ROYAL COMMISSION ON Biomass as a Renewable Energy Source · ROYAL COMMISSION ONENVIRONMENTALPOLLUTION – BIOMASS AS A RENEWABLE ENERGY SOURCE 5 means that most of our fuels will

ROYAL COMMISSION ON ENVIRONMENTAL POLLUTION

Biomassas aRenewableEnergy Source

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About the Royal Commission on Environmental Pollution

The Royal Commission on Environmental Pollution is an independent standing bodyestablished in 1970 to provide authoritative advice on environmental issues. Its terms ofreference are:

To advise on matters, both national and international, concerning the pollution of the environment;on the adequacy of research in this field; and the future possibilities of danger to the environment.

Within this remit the Commission is free to consider and advise on any matter it chooses;the UK government or the devolved administrations may also ask it to consider particulartopics.

The primary function of the Commission is to contribute to policy development in thelonger term by providing a factual basis for policy-making and debate, and setting newagendas and priorities. It considers the economic, ethical and social aspect of issuesalongside the scientific and technological aspects. It sees its role as reviewing andanticipating trends and developments, identifying fields where insufficient attention isbeing given to environmental problems, and recommending actions that should betaken. The Commission has published 24 reports, and many of their recommendationshave been accepted and implemented by successive governments.

The members of the Commission have a wide range of expertise and experience in naturaland social sciences, medicine, engineering, law, economics, and business. They serve part-time and as individuals, not as representatives of organisations or professions.

A full-time Secretariat supports The Chairman and Members by arranging and recordingmeetings and visits; gathering and analysing information; handling finances andadministration; and drafting and publishing the Commission’s reports.

In the course of its studies, the Commission canvasses a wide range of views. Informationon its work (including minutes of meetings, background papers by consultants andsummaries of evidence submitted) is available via www.rcep.org.uk.

BIOMASS AS A RENEWABLE ENERGY SOURCE

A Limited Report by

The Royal Commission on Environmental Pollution

Contents Page

CHAPTER 1 – Introduction 3

CHAPTER 2 – Biomass fuels 9Energy crops 9Forestry products 21Sawmill co-products 24Municipal arisings 26Conclusions 28

CHAPTER 3 – Generation using biomass fuels 30General principles 30Heat generation 31Combined heat and power 33Electricity generation 40Environmental implications 43

CHAPTER 4 – Meeting the target 47Economics of biomass 47Transport 52Energy conversion facilities 58Land-take 60Planning for biomass 63Phased delivery 67A strategic approach 68

CHAPTER 5 – Conclusions and recommendations 69

APPENDIX A – Policies to support biomass – description of current 72schemes

APPENDIX B – Case studies 75

APPENDIX C – Scope and limitations of the special report 83

APPENDIX D – Conduct of the report 85

APPENDIX E – Members of the Commission 88

APPENDIX F – Reports by the Royal Commission on Environmental 89Pollution

REFERENCES 90

ROYAL COMMISSION ON ENVIRONMENTAL POLLUTION – BIOMASS AS A RENEWABLE ENERGY SOURCE 1

2 ROYAL COMMISSION ON ENVIRONMENTAL POLLUTION – BIOMASS AS A RENEWABLE ENERGY SOURCE

CHAPTER 1 – INTRODUCTION

Context1.1 Energy consumption throughout the world, but particularly in industrialised societies, has

been steadily increasing. Much of the energy consumed, 97% in the case of the UK1, comesfrom non-renewable sources. The present use of carbon-based non-renewable energy isunsustainable, inter alia because of the effect of the resultant carbon dioxide (CO2)emissions on the global climate. Reduction in demand must be part of the solution2 butalternative energy sources must also be developed. All energy sources come withenvironmental penalties, whether from the construction of dams and barriers or from theimpact of renewable sources such as wind on rural landscapes, but these impacts must bebalanced against the necessity of developing low-carbon sources that are botheconomically viable and also secure.

1.2 The Royal Commission’s Twenty-second Report, Energy - The Changing Climate published in 2000, advocated a number of steps that the government should take, both in terms ofdomestic policy and through international negotiation. A key recommendation was that along-term target should be set to reduce CO2 emissions by 60% by 2050. This was based onthe contention that the maximum concentration of CO2 in the atmosphere should notexceed twice the pre-industrial level. The government subsequently accepted that the UKshould put itself on a path towards this aim3. In order to reach a 60% reduction of CO2emissions, it is vital for the government to concentrate on encouraging low- or non-carbonelectrical and heat generation. As a component of a renewable energy generation mixture,biomass should play an important role.

1.3 There are three types of indigenous biomass fuel: forestry materials, where the fuel is a by-product of other forestry activities; energy crops, such as short rotation coppice (SRC)willow or miscanthus, where the crop is grown specifically for energy generation purposes;and agricultural residues, such as straw or chicken litter. Biomass can also be imported,mainly in the form of pelleted sawdust (which is already an internationally tradedcommodity).

Why Biomass?1.4 Wood is a renewable fuel; its production and use is almost carbon neutral. Trees absorb

CO2 to photosynthesise organic compounds using solar energy. The energy is storedchemically and released when the wood is subsequently destroyed - whether by naturaldecay or combustion. Hence, although CO2 is released into the atmosphere when wood isburnt, an equivalent amount of CO2 has been taken from the atmosphere during growth.Some net release of CO2 would take place if the growing, processing or transporting of thewood involved the use of fossil fuel.

1.5 The carbon in biomass used as fuel does not therefore contribute to greenhouse gasemissions. Technically emissions from biomass use are reported in the UK greenhouse gas



inventory as a memo item, but are not included in the national total. This is in accordancewith international guidelines from the Intergovernmental Panel on Climate Change(IPCC) and the United Nations Framework Convention on Climate Change (UNFCCC).On the other hand emissions of nitrous oxide and methane from the combustion processare included in the national total (because the carbon is balanced by photosynthetic uptakebut the methane and nitrous oxide are not). Emissions of nitrous oxide from any fertiliserused to grow the biomass are also included, as are emissions of CO2 from fossil fuel used inforest or field operations and transportation.

1.6 Unlike most other renewable energy sources biomass can be stored and used on demand togive controllable energy. It is therefore free from the problem of intermittency, which is aproblem for wind power in particular. Also, unlike most other renewable sources, biomassoffers potential as a source of heat as well as electricity, offering high conversionefficiencies. This potential appears to have been overlooked in government policies topromote biomass, which have concentrated on electricity generation. In this report wetherefore concentrate on biomass as a fuel for heat or combined heat and power (CHP) . Wewill show that biomass energy offers an opportunity to rethink energy generation and todrive a step-change in the efficiency of power and heat production. The implications for theUK’s CO2 reduction targets are highly significant.

1.7 Biomass energy technology is inherently flexible. The variety of technological optionsavailable means that it can be applied at a small, localised scale primarily for heat, or it canbe used in much larger base-load power generation capacity whilst also producing heat.Biomass generation can thus be tailored to rural or urban environments, and utilised indomestic, commercial or industrial applications.

1.8 The technology is most efficient where a source of fuel and a demand for heat are within aneconomically viable distance of each other. In this report we examine the costs oftransporting biomass fuels, both financially and in terms of CO2 emissions. We show that wemight expect a significant proportion of the UK to be able to meet the maximum distancecriterion for efficient use of biomass. In some areas of the UK fuels could be grown as energycrops and in others it would arise as a by-product of agriculture, forestry and other activities.

1.9 Biomass offers important opportunities for UK agriculture and the countryside. As theNorth Sea resources become exhausted, the shift from coal to oil and gas-fuelled generation

Box 1A Units of energy production

Rates of production of energy are measured in watts (or kilowatts (kW), megawatts(MW) or gigawatts (GW)). If a production rate of one watt is maintained for one hour,the amount of energy produced is one watt-hour.

This report uses watts and the units derived from watts to indicate energy generally.Where it is important to distinguish heat (thermal energy) from power (electrical energy)a suffix (th or e, respectively) is used. For example a CHP facility with a total output of 40MW might typically produce 30 MWth and 10 MWe.


means that most of our fuels will come from outside the UK. This dependence oninternational sources for our fuel reduces security of supply and marginalises the domesticagricultural sector. Biomass energy provides an opportunity to develop a fuel source fromthe UK’s own resources, increasing the security of its energy supply; it also offers newopportunities for UK agriculture.

Why not biomass?1.10 Biomass has been successfully used as a source of energy across Europe but it has not

become established in the UK; there are several reasons for this. The main problem is thatthe government’s capital grants schemes for biomass initiatives have focussed on high-technology approaches to electricity-only generation with a view to potential exportdevelopment. Demonstration schemes have not been based on established biomasstechnology and they have consequently failed, with resulting loss of confidence. Thefailure to recognise heat utilisation as an important way of delivering high-efficiency energymeans that opportunities have been lost. Climate change policy, not speculative exportpossibilities, should be the primary driver for developing the biomass sector in the UK.

1.11 Additionally, the complexity of grant schemes has made it difficult to make headway intodeveloping this sector. In this study we identified 14 different grant schemes, but found nonational co-ordination. Similarly there is no national facility for the sharing of informationand experiences on biomass. At present it is too difficult for the biomass sector to grow andgovernment policies that are meant to make this process easier fail to do so.

1.12 These problems however are institutional rather than technical. There is no fundamentalreason why the UK biomass industry should not follow the route that has proved to besuccessful in countries such as Sweden, Denmark, Austria and New Zealand. However,growth of energy crops requires water and land and can have implications for biodiversityand landscapes.

1.13 In this report we address these issues and discuss how they are likely to affect the take-up ofenergy crop production in the UK. Any extensive use of biomass could also have significanttransport implications, and planning must allow for and minimise the associated costs andimpacts.

1.14 Combustion of biomass generates gaseous emissions and considerable quantities of ash,some components of which (such as dioxins and heavy metals) are potentially harmful.This report discusses these emissions and makes recommendations for the reduction ofemissions and the handling of solid wastes.

Strategy

Targets

1.15 This study was carried out following the publication of the Energy White Paper, whichaccepted a number of the recommendations in our Twenty-second Report. Here we expand


upon those recommendations and offer policy-based guidance on how to achieve them. Inparticular we recommended that by 2050 up to 16 Gigawatts (about 12%) of the nation’senergy should come from biomass (Table 1.1). This would be a clear but not dominant rolefor biomass within a larger, diversified energy portfolio. Our Twenty-second Reportillustrated four possible scenarios for the future of UK energy generation, all of whichrequired some degree of biomass generation to meet the 60% CO2 reduction target. Table 1.1 summarises the contributions required from biomass as set out in the fourscenarios in the Twenty-second Report.

Environmental, social and economic implications

1.16 This report describes the agronomic, technological and infrastructure developments thatwould be needed to deliver sufficient energy from biomass. In doing so, it discusses theenvironmental, social and economic implications of each component.

Environmental

1.17 Setting aside the savings in CO2 emissions, which are common to all renewable energysources, the production and use of woody biomass as an energy source will have bothpositive and negative effects on the environment. While these may be difficult to quantify,we have seen evidence that the net impact will be positive. Experiences in countries such asAustria and Sweden where use of biomass is well established are particularly encouraging.Given the limited experience in the UK, it is important that care is taken to learn fromexperience elsewhere to minimise adverse effects. Environmental impact assessmentsshould be carried out and the evidence reviewed at each stage of the development of abiomass energy sector.

Social

1.18 Experience in Austria and Sweden has shown that if biomass energy is introducedsensitively and transparently, society welcomes it. Local concern may well arise if peoplesee evidence of large-scale landscape changes as energy crops are introduced, or are not

Table 1.1 - Biomass targets from the Twenty-second report

Scenario Biomass Total UK Biomass as % of totalGW GW GW

1 16 205 8

2 16 132 12

3 7.5 132 6

4 3 109 3

satisfied that the local impacts of energy generating plants have been properly addressed.However, guidance and standards are available to address these concerns, and it isimportant that these are carefully applied.

Economic

1.19 We have also considered the cost of biomass energy. The cost of the fuel is comparable tothat of fossil fuels (particularly when the external costs of CO2 emissions are taken intoaccount), but the capital investment required is generally higher. In addition the grantstructure to support biomass utilisation is both complex and incomplete when comparedto the support available to other forms of renewable energy. It is not well suited tosupporting an energy source that delivers heat as well as electrical power. There is a need tostimulate markets for heat, and there are opportunities now to do this. We have maderecommendations to address this.

A staged approach

1.20 A successful biomass energy strategy requires that by 2050 much of the fuel needed will begrown as energy crops, and this means that potentially significant amounts of agriculturalland will need to be diverted to this use. However, in the shorter term there are existingsources of biomass to fuel the development of the sector. We have identified four stages inthis process:

• Immediate future - energy crops utilise a relatively small proportion of set-aside land.

• Short-term - area required for energy crops increases to an area equivalent to theamount of set-aside land.

• Medium-term - area required for energy crops increases beyond the amount of landthat is currently set-aside.

• Long-term - area of land increases to be a significant proportion of total availableagricultural land.

The timing of these stages and the amount of land that will ultimately be needed by 2050for growing energy crops will depend on the availability of other biomass fuels, especiallystraw and forestry arisings. We consider fuel availability in chapter 2.

1.21 In chapter 3 we discuss the different approaches to converting biomass to heat and power.We question the appropriateness of the government’s current emphasis on high-tech powergeneration and we concentrate on the use of relatively simple heat or CHP plants, and onco-firing in existing stations – these are technologies that are already available or are close tobeing proven.

1.22 Chapter 4 brings our conclusions on fuel resources and conversion facilities together intoa new strategy for developing a biomass utilisation programme over the next few decades,based around the four stages described above. We calculate the number of energy plants that would have to be built and the amount of land that would need to be



brought under energy crop production, and map these onto the four-stage model. Chapter 5 is a summary of our conclusions and recommendations.

1.23 Our proposed strategy does not cover biofuels for transport or energy carriers such ashydrogen produced from hydrocarbons. As described in the Twenty-second Report andour analysis of the environmental impacts of air travel, transport is a prime user ofhydrocarbons. Fuels such as bioethanol from cereals and biodiesel from oil seeds may havea role as fuels for surface transport4. Applications of woody biomass to produce transportfuels are more speculative, they are not covered in this report as we view them as longer-term possibilities that might be appropriate if surplus biomass or land is available once themore immediate applications have been exploited.

1.24 We also make the point that woody biomass gives a higher energy yield per hectare thantransport fuels from cereals or oil seed crops. However, in a climate of changing policies andincentives, farmers will naturally prefer to plant annual crops rather than woody materialswhich require a commitment to one crop for many years. This leads to a further theme inour recommendations: that development of a biomass sector is dependent on stable long-term policy.


CHAPTER 2 - BIOMASS FUELS

2.1 Biomass for fuel can be gathered or grown. Energy crops are grown using agriculturalmethods; in this chapter we shall examine the main species suitable for use in the UK andthe methods of cultivation, economic value and impacts through land-take, water use andsoil contamination. Forestry and municipal tree management both lead to substantialarisings of woody plant material that could be gathered for fuel and we shall consider thelikely arisings in the UK. The potential resources of straw from cereal and oil seed crops arealso considered.

Energy Crops

Species

2.2 Willow (Salix spp.) has already been used in commercial or near commercial operations inthe UK. Investment in developing new varieties with increased yield stability and improvedcrop management has made willow increasingly competitive as an energy source(paragraph 4.2). Willow chips are a reliable source of fuel of a consistent quality, suitable forfiring in CHP and district heating plants. Willow has been grown extensively inScandinavia for fuel, and in Sweden some 15,000 hectares of land are dedicated to itsproduction for renewable energy. Consequently, much more information aboutcultivation, harvesting and yields is available for willow than for the other potential energycrops. The grass miscanthus (Miscanthus spp.) is attracting an increasing amount of interestbut it is still largely at trial stage in the UK.

2.3 Among other potential candidate species, poplar (Populus spp.) is closest to providing analternative source of fuel. Poplar is being trialled in short rotation coppice (SRC)plantations, as well as being tried in silvoarable agro-forestry where it is intercropped witharable species. Straw has also been used as fuel and has the advantage of being a by-productwith which farmers are familiar.

Cultivation, harvesting and yield

Willow

2.4 Short rotation coppicing (SRC) is the most promising way of growing willow quickly andeasily. Breeding programmes are continuously developing new varieties that have higheryields, better growth characteristics (straighter stems for easier harvesting for example), andmore resistance to pests and pathogens. Willow is easy and relatively inexpensive to plantusing cuttings. The stems are cut into 2 metre lengths before transportation (they can befrozen if travelling long distances). A Swedish company5 has developed a step-planter thatcuts the stems into 15cm sections and deposits them in the soil. They are then pushedfurther into the soil with a roller and left to take root.


2.5 The first year of growth is cut back to encourage rapid, thick growth in the second to fourthyears. The willow is ready for harvesting and chipping after three years of regrowth. Thestems are cut above ground level and the stumps are left to reshoot. An average willowcoppice can be harvested over 15-20 years and the land can readily be returned toconventional crop use in 1-2 years by ploughing in the roots and treating the soil and weedswith herbicide.

2.6 Willow is capable of benefiting areas with loose topsoil because its roots grow into a mat-like mass immediately below the surface of the soil, which helps to retain the topsoil. Theleafy canopy prevents saturation of the land during periods of heavy rainfall, reduces soilerosion from run-off and prevents nutrients from entering streams.

2.7 Levels of pest or pathogen damage that are considered unacceptable in food crops can betolerated in plants that are destined to be burned. Consequently, established SRC can bemanaged with few pesticide applications without incurring significant economic penalties.Integrated Pest Management (IPM) has been addressed mainly for willow, but a number ofthe recommendations could be extended to poplar. The resistance of willow genotypes toinfestation by various pests and pathogens is well understood, as are site-dependent factorssuch as plants present in adjacent areas that might act as hosts to divert fungal diseases. IPMfor willow SRC recommends the planting of up to five varieties of different ages in aplantation to enhance biodiversity. It also recommends strategic planting to concentratepests and pathogens in smaller areas of coppice, reducing the scale of chemical applicationneeded to control the pests6. Rabbits are a pest that cannot be controlled through the use ofIPM, they can pose a significant threat to willow shoots and rabbit-proof fencing is costly,especially on irregularly shaped plots of set-aside land with high boundary to area ratios.

2.8 The emphasis, when planning SRC plantations, should be on utilising local knowledge andplanting varieties that have been tested previously on a similar site. Tailoring the plantationto the local environment is essential. Attention to detail at the planning phase can result inwell-designed, healthy coppices with high yields, low disease and pest susceptibility andimproved biodiversity.

2.9 Conventional willow harvesting machinery cuts and chips the stems simultaneously. Byplanting the willow in rows, high chipping rates can be achieved. It is important to harvestwillow in winter as it results in better wood with lower water content and allows nutrientcycling from fallen leaves. The harvesting equipment that has been used so far is based onthat used in Sweden. There, willow is harvested in winter and the frozen ground makes itpossible for heavy machinery to move over the land without causing excessive soil damage.In the UK the land does not freeze to the same degree as in Sweden and so this type of heavyequipment is not suitable. A UK willow growers’ group has gone some way towards solvingthis problem by using an imported sugar cane harvester7. There is no need for frozen soilduring harvesting as the mat-like roots of the willow plants adequately support the lightermachinery.

2.10 The UK transportation infrastructure cannot yet match the rate of willow chip production, sochips would have to be stored at the side of fields and reloaded onto trucks. The cost ofunloading and reloading chips for later transportation can be restrictively high both


economically and energetically, and storage times and methods need to be controlled to avoidthe development of fungi leading to biodegradation, and the build up of excessive moisture.

2.11 The cane harvester used in the plantations established around the Arable BiomassRenewable Energy (ARBRE) plant (paragraph 3.35) harvests the wood in rod form, which iseasier to transport and store and has a higher bulk density with lower moisture content.Storing the materials in rod form also reduces the loss of material and calorific value due to

decomposition during long-term storage8. The rods are then chipped before use, or, ifdestined for use in a co-firing plant (paragraph 3.42), can be milled directly into wood dust.

2.12 UK farmers and test centres have reported varying yields for willow SRC. This variation islikely to be the result of the variable quality of the plants, suitability of the land and more orless effective management. Yield has also been found to depend on planting density andfrequency of harvesting9. Farmers currently see willow as a marginal crop and will make useof subsidies by planting on set-aside land. The land chosen for set-aside is often the lowestquality land and this could also result in reduced yields. Weeding and fertilising areimportant in the first year of growth; if it is not carried out effectively then yield may drop.Fertilising can be important throughout the growth cycle, though the amount required forwillow SRC is significantly less than for arable crops.

2.13 Climatic factors also have an impact on yield. Willow requires substantial quantities ofwater and suffers reduced growth in dry conditions or dry years. Wetter regions of the UKmight be expected to be better suited to growing willow than others, though farmers havehad successful willow crops in drier areas of the UK so it seems that other factors may alsobe important10. The requirements for water should be considered as part of the overall waterdemand when crops are to be grown to provide energy for new building developments.

Coppiced poplar wood chips in farmer’s hands


2.14 Over the three years between harvests, the yield for willow should be ~ 20-25odt (oven driedtonnes) per hectare (but it can be higher if grown under optimum conditions with additionalfertiliser and water). This can deliver an income of > £100 per hectare per year (ha/y) inaddition to grants and subsidies. Under the current arrangements for grants and subsidies, thegrowing of energy crops is only considered to be viable at yields of 10 odt/ha/y or more11.Yields of willow at this level are achievable through careful agronomy and by building onexperience. Willow is less economically viable as a fuel for electrical generation only, and inchapter 3 (paragraphs 3.4 to 3.33) we have explored ways of adding value to the crop byexploiting the potential for using it in CHP and heat-only generation plants.

Poplar and other tree species

2.15 Poplar has been trialled on a much more limited basis in the UK and results have varieddramatically from site to site. Planting of poplar is more difficult than with other energycrops because it is not easily propagated from cuttings. Good apical buds are needed foreffective planting and growth. Planting machinery has not yet been developed and currentpractice is to use a cabbage planter; success with this machinery is limited and there is realscope for technological developments to make the process much easier and more effective.Land used for poplar is more difficult to return to normal agricultural use than that used forwillow, as the deep woody roots are difficult to remove.

2.16 Willow harvesting methods are also likely to be relevant to poplar although harvesting maybe needed more frequently due to the fast growing stems that thicken quickly.

2.17 Poplar trials in the UK have revealed that the yields are very site specific. In some casespoplar yield has outperformed willow by up to 66% but in others poplar yield has been aslow as 30% of willow production12. The wide variation in yield, dependent on a number ofsite-specific factors, could prove an obstacle to wide scale adoption of poplar as an energycrop in the UK but does not rule out its use in those areas that are suited to its production.

2.18 Increasing the variety of energy crop options available to farmers enables planting to bedetermined by local environmental factors, which increases farmer confidence. This alsoenhances security of supply for generators, as farmers will be able to plant crops that aremore likely to thrive in their locality thus making harvests more reliable than if only a singleenergy crop option were available. It is our opinion that the influence of site suitability onyield means that farmers should be allowed as much flexibility as possible when movinginto biomass fuel production. Planting should be guided as much as possible by localknowledge and farmers’ experience of the type of crops that they can grow on their land,not by planting grants for specific crops. We recommend that producer group grants beextended to include producers of energy crops other than willow. We also recommendthat the Scottish Forestry Grant Scheme be similarly extended to cover all possiblesources of biomass.

2.19 Short rotation forestry (SRF) is another option for the cultivation of a number of treespecies for energy. In SRF, trees are grown closely (as single stems) and harvested after 5-15years. Of the many coniferous and broad-leafed species that have been trialled, ash(Fraxinus spp.) may be the most suitable, but it requires good soil that is not acidic. On

poorer, wetter soils, alder (Alnus spp.) has potential. In the short term SRF is not seen as amajor source of biomass for fuel, but this could change in the future.

Miscanthus

2.20 Like wheat, miscanthus (also known as elephant grass), is a member of the grass family(Gramineae) and is grown using conventional agricultural methods and harvested annually.It is gaining favour with farmers as it is planted, harvested and stored using existing farmequipment and methods. It is cut and baled with a straw baler and stored in barns. It thusrequires less capital investment than willow. Farmers also have more confidence in usingcurrent farming practices. The main disadvantage of miscanthus is that it can be difficult torehabilitate the land for other uses due to its deep root structure.

2.21 Miscanthus is a genus of about 20 species native to tropical Asia and Africa and like mosttropical grasses (such as maize, but with the notable exception of rice), it carries out amodified form of photosynthesis, known as C4 (Box 2A). Most C4 grasses are cold sensitiveand do not grow well in cool regions. Miscanthus x giganteus, the cross most commonly usedfor biomass production, is fairly cold tolerant and can grow (rather than just survive) attemperatures that would not suit some arable C4 crops such as maize. Unlike maize,


Box 2A C4 photosynthesis

The key reactions of photosynthesis are the same in all plants. Light energy is convertedinto chemical energy, with the production of oxygen as a waste product. The energy is usedwhen carbon dioxide (1 carbon atom per molecule) is added to the 5-carbon atom sugarribulose bisphosphate producing, after several stages, two molecules of the 3-carbon atomsugar, triose phosphate. This is the C3 pathway, and is the starting point for synthesis ofalmost everything else in the plant: sucrose, cellulose, amino acids etc.

The enzyme that carries out the reaction to produce triose phosphate also catalyses areverse reaction, a process known as photorespiration, in which oxygen is used and carbondioxide generated. This is a waste of much of the light energy that could have been used toproduce sugars etc. However, photorespiration can be suppressed by increasing theconcentration of carbon dioxide at the site where it occurs.

C4 plants can change their internal concentrations of carbon dioxide by temporarystorage of carbon dioxide in C4 acids, such as oxaloacetic acid, formed from C3 acids inleaf mesophyll cells. From there acids are transported to bundle sheath cells (locatedaround the leaf veins) where carbon dioxide is released and the donor acid returned to themesophyll cells. In the bundle sheath cells carbon dioxide is at a higher concentrationthan in the mesophyll cells and thus photosynthesis can occur without photorespiration.

C4 plants are more efficient than C3, particularly at high temperatures, and many are alsothought to control their water use more effectively. C3 plants typically have transpirationratios (g water lost per g carbon dioxide fixed) in the range 490-950 compared to 250-350for C41. Maximum growth rates (g m-2 day -1 ) are correspondingly higher: 34-39 for C3compared with 50-54 for C4.

1 (Hamlyn G Jones (1993). Plants and microclimate CUP).


miscanthus maintains high levels of key C4 enzymes that function at low temperatures tomaintain high rates of photosynthesis13, although leaves may expand more slowly at lowtemperatures14. Successful growth of miscanthus has been reported at an altitude of 300mabove sea level on the Yorkshire Wolds. As with several C4 grasses such as genotypes ofsugar cane, there is evidence that endophytic nitrogen fixing bacteria can occur inmiscanthus15. This could reduce the need for nitrate fertiliser, but is likely to be verygenotype-specific. There is also evidence that miscanthus may have a positive effect onnutrient cycling and soil organic matter content (carbon and nitrogen)16. Miscanthus iseconomical in its use of nutrients and has a good internal recycling system, where much ofthe N, P and K (nitrogen, phosphorus and potassium) is translocated from leaves and stemsand stored in the unharvested rhizome fraction. Defra cites an ash content of 2.7% (of drymass), which is below average for this type of plant (paragraph 2.24).

2.22 Miscanthus is widely grown as an ornamental plant, because of its attractive inflorescences.Genotypes developed for biomass are selected for delayed flowering and for infertilehybrids to avoid it becoming a weed17, (miscanthus is propagated by rhizomes or bymicropropagation, so seeds are not needed to produce material for commercial use).Although relatively efficient in its use of water, miscanthus yields may still be reduced bydrought: genotypes with tight control of transpiration have been identified for use inbreeding programmes18.

2.23 There are fewer sites planted with miscanthus for energy production in the UK thanwith SRC so information is more limited. Of the seven sites for which results areavailable19, two failed to achieve regular yields of 15 odt/ha/y, and one of these failed toachieve the accepted profitability threshold of 12 odt/ha/y. Four of the remaining fivesites achieved yields in excess of 20 odt/ha/y in one or two years. However, reliableplanting and development of miscanthus rhizomes remains an issue given the limitedexperience to date.

Other grasses

2.24 Most work on evaluating grasses other than miscanthus has been carried out on canary reedgrass (Phalaris arundinacea), a C3 species native to Europe. Canary reed grass is a rhizomatousperennial that is grown from seed, reducing establishment costs, and can be harvested 2-4 timesa year. It produces harvestable material earlier than miscanthus and can be processed with thesame machinery as wheat straw. It can be grown in cold areas such as Finland20. The first harvestin the spring is of the previous year’s growth, before new tillers are produced; this has a lowwater content (10-15% dry weight). It does not need high levels of nitrogen, indeed it can beused to take up nitrogen from polluted waters and it may have an additional use in cleaning upheavy metals from municipal sewage21. On the other hand it can become very invasive ofwetlands and is in fact banned from some areas in North America. Canary reed grass was oneof four perennial rhizomatous grasses selected for evaluation for energy crops in Europe andUSA. The others were miscanthus, giant reed C3 (Arundo donax) and switch grass C4 (Panicumvirgatum). Both giant reed and canary reed grass inhabit wetlands, and so would not be asuitable alternative to arable crops on high grades of agricultural land. The ash content of C4grasses is typically around 8%, about double that of C3 grasses. This ash is primarily fine silica,which adds to the fly ash produced when the grass is burned22.

Straw

2.25 Cereal crops consist of roughly equal parts grain and straw, oil seed crops such as rapeproduce roughly 1.5 tonnes of straw per tonne of seed23. These ratios imply that the totalamount of straw produced in the UK was almost 24 million tonnes in 2002. This straw maybe used for animal feed or bedding, and there are limited export markets, for example toHolland for use in tulip cultivation.

2.26 Many farmers prefer to plough straw back into the field to improve the organic content andtexture of the soil. This use for straw has only come about in response to a ban on burningstraw, which had been the practice for many years, and there are divergent views on itsbenefits, especially in terms of nutrient content (paragraph 2.27). The volume of strawavailable in the UK is considerable and it is likely that a significant surplus would beavailable for use as fuel from those farmers that choose to market it for energy generation.

Environmental implications

Energy use during production

2.27 Table 2.1 shows the energy use and CO2 equivalent emissions from fuel production,including direct inputs, indirect inputs and resource-related inputs. These have beenconverted from values per wet tonne to values per oven-dried tonne (odt). Two values forenergy use and emissions for straw have been given as a result of the possibility of varyingfertiliser input assumptions (paragraph 2.26), which have a large influence on the estimates.In case (a), fertiliser inputs are used to replace nutrients lost when straw is removed from thefield instead of being ploughed in. As a result, indirect and resource energy use andemissions are large, and are significantly greater than for the other fuels. However, if it isassumed that replacement fertiliser is not needed (case (b)), the energy and emissions are


Table 2.1 Energy use and greenhouse emissions from fuel production24

Resource Energy use (Mj/odt) CO2 equivalent emissions (kg/odt)

Forestry residues 572 33

(chips)

Straw 1253 (a) 171 (a)

(baled) -31 (b) -4 (b)

Short rotation coppice 756 35

(chips)

Miscanthus 338 40

(baled)


negative compared with ploughing in. But even in the worst case, the CO2 savings fromusing biomass rather than fossil fuel (about 1,000kg CO2/odt equivalent for gas) massivelyoutweigh these emissions.

Water requirements

2.28 The high water requirement of willow can constrain its use to areas where sufficientirrigation water is available at reasonable cost and without unacceptable environmentaldamage (paragraph 2.13). However, municipal sewage or sewage sludge can be used toirrigate willow, and will provide both additional nutrients and water25. Water companieshave already shown an interest in this disposal routei, which could provide an additionalrevenue stream for farmers as well as reducing their fertiliser input costs.

Willow and heavy metals

2.29 The high heavy metal content of sewage used as fertiliser can raise concerns over soilcontent. Willow, however, will take up heavy metals, particularly cadmium, andconcentrate them in the wood. Willow plantations can therefore actively reduce levels ofmetals in contaminated soils26 (Figure 3-V) and can be used for the bioremediation ofcontaminated land. Subsequent care in managing the ash from energy production isimportant to prevent unacceptable build up of heavy metals in the soil. We address this inchapter 3 (paragraphs 3.53 - 3.56).

Landscape

2.30 The English landscape is not constant; it has been in a state of change for centuries ashumans have changed the use to which they put the land27. Change need not beundesirable, but substituting one landscape for another will be of significance to those whovalue the landscape and decisions on land use should be made cautiously. A change of landuse from arable cropping to willow coppicing or miscanthus cultivation over a large areawould have a significant impact on the landscape - a mature willow crop can grow to fourmetres in height before harvest and miscanthus can reach similar heights.

2.31 Willow plantations need not be visually intrusive if planting is planned sensitively. TheForestry Commission has produced a guideline note28 on planning plantations of SRC(willow in particular) and minimising the impact on the landscape. The guidelinesindicate that irregular-shaped plantations on low-lying land that are sympatheticallyshaped and managed are the best option for such a visually intrusive crop. The ForestryCommission emphasises that planting coppices of various ages near to existing tall plants(woodlands for example) reduces dramatic landscape changes after harvest; it alsosuggests incorporating public rights of way and planting areas of shrubs around these toimprove diversity and visual interest. It is important to avoid planting large, geometricshaped coppices on high ground that can block local scenic views, especially inrecreational areas.

i Yorkshire Water’s initial interest in the ARBRE project was in using the SRC as a sewage disposal route.

2.32 Straw is a by-product of an existing crop so few, if any, landscape changes would be likely toresult from its adoption as an energy fuel. Likewise forests are an existing landscape featureand their use as a source of fuel will have little or no landscape impact but improvements inforest management could increase their accessibility for public recreation.

Biodiversity

2.33 Short Rotation Coppice provides cover that is not supplied by arable crops or grasslandand weeds are better tolerated. This can provide an environment attractive to smallmammals, invertebrates and insects29, which in turn attract many species of bird. Groundnesting birds are attracted to SRC especially after harvest or first year cutback. Sensitiveplanting of SRC can improve game bird prospects, and pheasants in particular value theshelter that a well-established crop can offer. An average SRC plantation can exist for 15 or20 years, providing a more stable and mature environment for wildlife than annual crops.This is particularly true for winter-sown cereals which, as currently managed, do notsupport a high level of biodiversity.

2.34 The fauna attracted to coppices are similar to those found in woodland. Planting SRCadjacent to woodland not only reduces the visual impact of the plantations but alsoprovides ecological corridors for the movement of wildlife. The cover provided by acoppice offers opportunities for bird watchers and animal enthusiasts as it also attractslarger mammals such as deer. Unfenced willow and miscanthus plantations may, however,shelter rabbits that may graze neighbouring crops.

2.35 Sensitive planning is central to the issue of improved biodiversity. Replacing wetlands orother natural habitats is likely to result in a net reduction in biodiversity. The water demandof willow means that the crop can have an impact on an area beyond the plantationboundaries especially if it is sited close to wetlands or small local streams. Fish and otherwaterborne creatures can be negatively affected by a reduction in the water table due to thehigh water demand of coppicing in nearby areas. This is addressed in the ECEnvironmental Impact Assessment Directive that requires an assessment to be carried outbefore uncultivated or semi-natural areas are converted into intense agriculture if this islikely to cause significant environmental effects30.

2.36 Poplar appears less able to enhance biodiversity than willow, particularly in respect toinsects31. However, poplar coppices can tolerate higher weed populations and weed seedsare an important bird food. There may also be benefits for biodiversity of invertebratessuch as spiders, beetles and slugs32. Poplar plantations also tend to sustain more stable anddiverse plant communities, with fewer annuals and invasive perennials33.

2.37 As yet there are few data available on the biodiversity impacts of other energy crops such asmiscanthus, though similarly a miscanthus plantation might provide better cover, higherweed-growth and lower pesticide usage than arable crops.

2.38 We recommend that the biodiversity benefits of energy crops be reflected in theEnergy Crops Scheme, with payments matching those available with respect tobiodiversity enhancement through the Countryside Stewardship Scheme. The Energy



Crops Scheme goes some way towards this by allowing open spaces within plantations to beincluded in the area that is counted in the awarding of grants, but payments based on setcriteria for sensitive planting of a variety of species and ages and incorporating public rightsof way and wildlife corridors would provide better incentives for farmers embarking onenergy crop production. The possibilities for integrating energy, farming diversity,

Box 2B Land classification in England and Wales

Agricultural land is divided into classifications by the physical limitations of the land foragricultural use, the determining factors being climate, site and soil and how these affect theversatility of the land and the reliability of crop yields1. England and Wales have fiveclassifications (or grades) and grade 3 is divided into subgroups a and b2, the Scottish executiveuses seven grades of land classification with up to three sub-categories in each3, The first fivefollow roughly the descriptions and proportions set out below for England and Wales4.

Grade 1 - excellent quality agricultural land

3% of agricultural land

Land that produces consistently high yields from a wide range of crops such as fruit, saladcrops and winter vegetables.

Grade 2 - very good quality agricultural land


Yields may have some variability but are generally high, some factors may affect yield,cultivation or harvesting.

Grade 3 - good to moderate quality land


Limitations of the land will restrict the choice of crops, timing and type of cultivation,harvesting. Yields are generally lower and fairly variable.

Grade 4 - poor quality agricultural land


Severe growing limitations restrict the use of this land to grass and occasional arable crops.

Grade 5 - very poor quality land


Land that is generally suitable only for rough grazing or permanent pasture.

1 Defra (2003). Agricultural Land Classification. Protecting ‘the best and most versatile agricultural land’2 MAFF(1988). Agricultural land classification of England and Wales3 Personal Communiction, J Hooker, April 2003.4 Defra. England ALC stats

biodiversity and recreation targets should be recognised and encouraged throughadditional payments to farmers that meet these standards.

Potential production

2.39 England has about 2.5 million hectares (Mha) of grades 1 and 2 agricultural land, 6 Mhaof grade 3 land and 3 Mha of grades 4 and 5 land. Food production is likely to continueon the best grade 1, 2 and 3 land but a significant amount of land in grades 3, 4, and 5 willbe available and suitable for energy crops. Environmental impact assessments may ruleout some areas of set-aside and grade 5 land for energy crop production onenvironmental grounds, or it may just be unsuitable (steep slopes or very poor quality soilfor example). Therefore it is more likely that grades 3 and 4 land will be used for willowproduction. Energy crop production could be started as a use for set-aside land but it islikely that eventually other arable land would need to be switched to energy cropproduction.

2.40 There are currently 1,795 hectares of land under cultivation of commercial willow SRC andmiscanthus in the UK34; at least 1,500 hectares of this is willow35. The land dedicated toenergy crops totals less than 0.01% of the total arable land in the UK36. The Defra Non-Food Crops Strategy states that domestically grown crops should meet a significant part ofthe demand for energy and raw materials in the UK37. The National Farmers’ Unionsuggests that up to 20% of crops grown in the UK could be made available for non-fooduses (i.e. for fuels or industrial materials), by 202038; hence, there is scope for a significantexpansion of energy crop production in the UK. Planning crops in order to achieve themaximum environmental benefits and yields in areas close to demand is the challenge to bemet by the farmers and energy generating companies

2.41 The implications for UK land availability can be considered in four stages:

• Immediate future - energy crops utilise a relatively small proportion of set-aside land.

2.42 For the immediate future, the indications from power plants in the planning stages are thatfarmers can be attracted to allocate sufficient land to growing energy crops by the existingset-aside and planting grants39,40 with a proportion of growers not using set-aside land.

• Short-term - area required for energy crops increases up to the amount of set-aside land.

2.43 The average set-aside land over the four years from 1999-2002 was 640,000 ha. It is unlikelythat all of this will be suitable or available for energy crops, for a variety of reasons includingfarmers’ preferences for other industrial crops, water availability, commercial return andland productivity. Therefore, it is likely that a change in grant regime will be required toensure that land equal in area to the total area of land that would otherwise be set-aside isused for non-food crops, with an appropriate proportion being energy crops. This is likelyto result in much set-aside land being returned to its former uses, with some land remainingfallow, whilst other land is converted from other crop production to energy and industrial



crops. The new CAP single payment scheme is understood to make energy crops morecommercially viable41 for farmers but additional drivers will be needed from government toencourage wider-scale take-up of energy crop production.

• Medium-term - area required for energy crops increases beyond the amount of landthat is currently set-aside.

2.44 As a viable fraction of set-aside is used for energy crops, growth in energy crops will moveonto other grades of land. The issues then become effective agricultural and forestry policyand the relative profitability of different land uses. Agricultural policy issues that ariseinclude import and export balances of food crops and the effect of a possible move to lessintensive and lower output farming methods. Within the UK there will be manygeographical variations, for example the availability of water for SRC, so the cover of thesenew crops will not be evenly spread throughout the country. Further evidence42 suggeststhat, in the short to medium term, Scotland will have sufficient biomass from forestryarisings and co-products to meet its needs and will not need to grow dedicated energy crops.

• Long-term - area of land increases to be a significant proportion of total availableagricultural land.

2.45 In the long-term, in addition to the economic and policy issues above, the environmentalimpacts would become more significant. Siting of energy crop production would beconstrained by both proximity to installations using the biomass and the suitability of theland. To achieve the levels of biomass energy production suggested by some sources43 wouldrequire at least 20% of the total available arable land area, and would be likely to result inmany large areas having much more than 20% of land area dedicated to energy crops.

Conclusions on energy crops

2.46 This land will not come into energy-crop cultivation unless it provides an adequate returnfor farmers. The Energy Crops Scheme (Appendix A, paragraph A.6) intends to encouragefarmers and end-users to work together and to ensure that supply and demand are bothsatisfied. It takes account of factors such as environmental and landscape issues as well asenergy requirements. The scheme already recognises the biodiversity value of SRC to someextent. We recommend that the Energy Crops Scheme be enhanced to make energycrops more viable for farmers, and be tied to specific planting standards to protectlandscape and other environmental features. This would help to reassure environmentalgroups and the public that SRC plantations cannot be established indiscriminately at theexpense of the local environment. It would also provide a higher income stream for farmers.

2.47 Successful cultivation of energy crops would have two positive outcomes. A fuel would beproduced for use in biomass energy generators in a way that is not a by-product of, andtherefore limited by, a different type of operation such as forestry or municipal tree surgery;and a valuable cash crop with additional financial support would become available forfarmers. Set against this are limitations imposed by processing and transporting the fuel.However, without guaranteed markets farmers are unable to receive Defra establishmentgrants for energy crops and they are understandably hesitant to dedicate large areas of theirland to a crop that is relatively new to the UK.

2.48 While in general willow and poplar perform better in wetter areas and miscanthus yieldsare likely to be higher in warmer areas less prone to frost, energy crops can be grown inmuch of the UK. A detailed investigation needs to be carried out into the suitability ofareas of the UK for biomass energy. We recommend that extensive detailed analysis ofthe suitability of land for energy crop production and a comparison of this topossible markets for the energy be undertaken on a regional basis. This should becarried out with central government support and guidance and should aim toincorporate environmental, agricultural and fuel poverty issues as well as economicconsiderations.

Forestry Products

Trends in availability

2.49 Historically, woodcutting has fuelled domestic or industrial stoves and has provided theraw material for products such as charcoal and other processed or semi-processed woodfuels. In the developed world the use of wood in this way has been largely abandoned infavour of other forms of energy, and forestry is now primarily directed towards theproduction of timber and paper pulp. The demand for paper pulp in the UK is decreasingas recycling increases, and the demand for construction timber from UK forests has alsodecreased; consequently the availability of wood for fuel has increased. Added to this, largeamounts of Britain’s forests were planted in the 1960s and 1970s and will soon be reachingmaturity without a clear market for the wood.

2.50 Figure 2-I illustrates the anticipated wood production from forests in Britain from 1994to 202144. Supply is predicted to increase over the next couple of decades, peaking atabout 10 million tonnes per year above current demand by 2020. Not all of these forestswill necessarily be replanted so wood production could decline after 2020. This,however, will be offset to some extent by bringing more forests under activemanagement. Demand for UK-grown timber might increase over the same periodbecause of the large-scale house building currently foreseen in government strategies forhousing and planning45. Competition from imported timber however will mean that UKmaterials will not be used to meet all of the domestic demand and some surplus woodwill still be available as fuel.

2.51 We expect that much of the extra 10 million tonnes per year of production by 2020 will be available as biomass fuel for energy, and that the supply will then fall to a leveldependent on the competitivity of the UK industry. Long-term supply cannot be predictedbut it is likely to be significantly higher than the current availability of 1.3 million tonnesper year.

2.52 A market for bioenergy in Britain would provide an opportunity for Britain’s forestindustry to receive income from its residues; giving the forest industry a market for its by-products and increasing its competitivity and helping it to resist decline. Under suchconditions the economic strength of the industry may be sufficient to utilise the increased



potential harvests projected in Figure 2-I. As the primary products comprise only half ofthe trees cut, a growing forestry industry would provide a growing supply of biomassresidues for energy purposes at a low cost. Whether demand for UK timber increases ordecreases over the coming decades, biomass energy provides an additional market thatcould complement other wood-based industries to develop the forestry sector.

2.53 Forestry materials available for biomass fuel arise as a consequence of other forestryactivities, so that the marginal energy costs of and emissions from its production areminimal. Should the production of fuel become again a major objective of forestry, itwould be necessary to investigate the costs and environmental impacts of keeping land inforestry as opposed to releasing it to other uses, as well as the energy requirement ofharvesting and transporting the materials. The opportunity to sell forest arisings as anenergy fuel could make forest management more economically viable. This is anopportunity to use an existing resource and improve the management of the UK’s forestsand woodland as a result. We recognise that it is important, however, to monitor the impactof removing arisings from the forest. In some areas the physical removal of arisings couldcause unacceptable effects on soil structure (leading to erosion) and nutrient retention(leading to possible acidification and eutrophication of waters). Sufficient materials mustbe left on the forest floor to prevent this from occurring.

2.54 Management of planted forests to produce fuel for energy could offer a valuable opportunityto rethink the UK’s forests and to replant with a diversity of indigenous species to replace thesingle species planting prevalent in many of the UK’s forests. This recommendation wasmade in the Commission’s Twenty-third Report46. We recommend that the WoodlandGrant Scheme for England and Wales take a similar approach to the Scottish ForestryGrant Scheme, which recognises this potential and structures the grant payments toreward planting of selected broadleaved trees in new and improved woodland areas47.

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Accessibility

2.55 If forests are located in remote areas, there may not be access for harvesting machinery ortransportation and it may be uneconomic or unattractive to invest in building roads.Building access roads in unspoilt areas is usually undesirable but this would only apply to asmall proportion of the UK’s forests and should not be considered a general obstacle to theuse of forestry materials for fuel. The long lead-time, uncertainty of supply (a glut followedby scarcity of supply in some areas following the 1987 storms for example), and a lack ofexpertise in harvesting methods all detract from the value of forest materials as a long-termsource of fuel compared to energy crops, for example, that are more controllable. However,in those areas close to forests, the benefits of using an existing local resource for energyproduction are clear.

2.56 Forestry products are not suitable for all modes of biomass conversion. The dispersed natureof the supplies makes it unlikely that they will be used for large-scale energy production. Thefuel is often insufficiently homogenous for small-scale plants without considerable pre-processing to increase the density and uniformity and reduce moisture content. A typicalproduct is compressed sawdust in the form of pellets but the energy and economicrequirements of such a process impacts on the suitability of the fuel and must be handledaccordingly – this is discussed below (Box 2C). The Finnish Alholmens Kraft is a very largecogeneration plant that is located at the site of a pulp plant so that both industrial residuesand forestry co-products from the primary product collection can be used as fuel48. Thiscould serve as a model for UK applications of biomass energy.

Impact on other industries

2.57 There are several industries that rely on forestry materials, particularly wood and sawdust,as an input material. In the absence of other factors a sharp rise in demand for biomasscould potentially increase prices and so decrease the competitiveness of such industries; ifso, this would need to be reflected in any economic analysis of biomass fuel. However,supply of forestry materials is increasing much faster than demand (paragraph 2.50) and asignificant increase in prices is unlikely to materialise49. In addition, these wood-basedindustries produce by-products that themselves have potential as fuel, and some farms andmanufacturers already use their own by-products to fuel small-scale CHP units (Box 2C).

Forests as Carbon Sinks

2.58 The Kyoto Protocol acknowledges the value of forests as carbon sinks and promotesafforestation as a way of achieving national targets for CO2 reduction set under Kyoto.Only forests that are planted post-1990 are eligible for accounting under this system.Carbon sequestration through afforestation accounted for around 0.4 million tonnes ofcarbon (MtC) in the UK in 200150. Use of surplus forest materials to displace fossil fuels asan energy source would have a much more significant impact than afforestation onreducing CO2 emissions towards the Kyoto targets.

Availability and costs

2.59 The dispersed nature of forest materials means that they are better suited to small scaleCHP or district heating applications. The rural location of most forests makes them ideally



placed primarily (but not exclusively) to serve rural communities. There is an opportunityto link biomass energy policy with rural regeneration and fuel poverty strategies. Theeconomic returns on rural schemes may be lower than in urban areas due to the lower heatdemand density in rural areas51.

2.60 Encouraging co-operatives between foresters would increase their influence in the energysector and spread the capital costs and risks between a number of stakeholders. Energygenerators are likely to support such moves; dealing with a single co-operative rather thana number of individual farmers or foresters reduces administration costs. We recommendthat the government investigates the possibility of extending the grants forestablishing producer groups to farmers and foresters who wish to use theirwoodlands or other arisings (hedgings for example), as a source of fuel but do not wishto plant energy crops.

2.61 The benefits associated with forests are not exclusive to rural areas. The Office of the DeputyPrime Minister’s (ODPM) Sustainable Communities programme (paragraph 4.18)incorporates the planting of a number of community forests for recreation. We recommendthat the infrastructure for management and distribution of forest resources should be anintegral part of the planning process; these materials should then be used in localcommunity heating or CHP schemes to improve the sustainability of these communities.

2.62 One of the key advantages of forestry material is that there is already a surplus of wood thatcould be made readily available for use as a fuel. With a supply peak around 2020 (Figure 2-I), forestry materials can be used to initiate the biomass energy sector and supportits development over the next couple of decades. This would allow energy crops to beplanted at a gradual rate enabling the environmental impacts of the change in land-use to beperiodically monitored and reviewed. By the time forestry materials begin to decline (post2020), sufficient energy crops should have been planted, and yields increased, to allowthem to take over the lead in energy production.

Sawmill co-products2.63 The main demand for forestry materials currently comes from sawmills but these mills

produce by-products that could in turn be used as biomass fuel in either their raw state orfollowing processing. Chipboard manufacturers would be in competition with energycompanies for sawmill by-products but they also produce by-products that could beemployed for energy production. Sawdust can be compressed into wood pellets that can beused in domestic or industrial applications. Pellets have the advantage of being dense, cleanand dust-free so they are easy to transport, store and combust in smaller-scale operationsthat require a more consistent fuel.

2.64 Using biomass resources produced on-site to provide heat and power for the pelletingprocedure, as Balcas does (Box 2C), reduces the environmental impact of the processsignificantly. Sawmills, chipboard manufacturers and other processors of virgin wood areideally placed to develop on-site biomass CHP and pelleting schemes along the Balcasmodel (albeit on a smaller scale).

2.65 In some European countries the take-up of small-scale domestic wood-fuelled heatersincreased dramatically with the increased availability of wood pellets. Wood pellets havebeen particularly successful in promoting the use of biomass for heat in Austria (Figure 2-II). A large pellet market and distribution system has developed that enableshomeowners to install domestic pellet heaters confident in the knowledge that they will beable to obtain a regular, reliable supply of fuel. In Salzburg, 50% of all new-build projectsnow incorporate biomass heating, 70% of which use pellets as fuel52.


Box 2C Pelleting sawdust

The pelleting process can be scaled according to the resource available. Balcas Ltd is acompany based in Northern Ireland that owns 4 sawmills, 2 pallet factories and an MDFmouldings plant. They have recently been awarded a capital grant from the DTI to build aCHP and pellet mill extension onto their sawmill in Enniskillen. Balcas will use surplussawdust and woodchip from the mill to fire a 15MW boiler to produce 2.7MW ofelectricity and heat to dry further wood, to produce wood pellets and power and heat theentire facility. The pelleting operation will produce 50,000 tonnes of pellets per year andthese will be sold to external customers.

This scheme will cut energy bills and fossil fuel consumption, and will dispose of the mill’sco-products in a safe and convenient way, which will bring additional income to thecompany (provided they have a market for the pellets).

Construction of the pelleting and CHP plants is due to begin in early 2004. It is worthnoting that the grant has been awarded only for the CHP facility and that there is nospecific government support for the pelleting operation under this particular initiative.

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Figure 2-II53 Biomass heating in Austria since 1986


2.66 The Forestry Commission estimates that the sawmill co-product available in Britain totalsaround 859k odt/y, 20% of which is sawdust54. There are existing markets for 98% of thisresource but the Forestry Commission estimates that around half the sawdust could bemade available for fuel without serious disruption to existing industries. Any increase inavailability of sawdust for pelleting in the future would come from either an increase insawmill activity or a decrease in other markets for sawmill co-products.

2.67 Any significant increase in pelleting in the short term would have to come from processingother sources of wood (willow, forestry materials etc). Wood Energy Ltd in Devon isdeveloping miscanthus pelleting to improve the manageability and density of the fuel andthey are currently trying to secure funding for firing trials55.

Municipal arisings2.68 The maintenance of parks, gardens, road and rail corridors and other green spaces in towns

and cities gives rise to plant cuttings that are typically woody and suitable for use asbiomass fuel. The civic community already incurs the costs of producing and collectingthe material as part of its normal operations, and any marginal costs of delivering to anenergy plant instead of to a landfill site will be slight if not negative, particularly if gate feesare consequently avoided. The increases in the landfill tax and the introduction of theLandfill Directive56 are requiring councils to look for alternative disposal routes for their biodegradable wastes.Using woody arisings toproduce energy is analternative route for thesematerials. Some of thematerial might be suitablefor composting, digestion orfurther processing into solidfuel (sawdust pellets) and thecost of this would depend on the local availability ofoutlets for its use in this way.

2.69 The Forestry Commissionestimates that the quantityof park and garden wastearising in towns and citiescould total 492k odt/y if this resource were exploitedfully. The dispersed natureof the resource makes thisfuel especially suited tosmall-scale, district heat orCHP production, to reducetransport distances and Forestry workers feed cut branches into shredder

costs. There are however few opportunities to store or process municipal materials atsource, which affects the possibility of allowing the fuel to dry to the low moisture contentrequired for some small-scale operations.

2.70 A project in South London, BedZED (Beddington Zero Energy Development), will usewood from municipal tree management in a small CHP plant using gasification in ahousing development that aims to be energy-neutral (Box 2D). It was funded by capitalgrants from the Combined Heat and Power Association (CHPA) and the Energy SavingTrust (EST). The EST was established by the DTI to encourage the sustainable use of energyand to help the government to achieve its carbon reduction targets. There has been nodirect government involvement in the scheme but Patricia Hewitt (Secretary of State forTrade and Industry) chose BedZED as the site of the launch of the Community Energyprogramme, thereby lending weight to the scheme.

2.71 Some councils are piloting biomass CHP and district heating schemes in their publicbuildings. Nottinghamshire County Council, for example, has installed biomass heating inthree of its schools, to be fuelled by forest materials from the local area. However, theycurrently have to use more expensive wood pellets as it is proving problematic to establisha reliable supply chain from local foresters in the absence of government support57. Thisprovides the public with examples of the application of reliable, efficient CHP andencourages acceptance of the new technologies but the supply chain problems must beresolved to attract further interest in biomass schemes.


Box 2D BedZED

BedZED, the Beddington Zero Energy Development, is a development of 100properties including housing, work units, shops and green spaces. It has been designedto have as little environmental impact as possible. Through the combination of energyefficiency and sensitive design it is estimated that residents will see a 60% reduction inheat demand compared to a typical suburban home.

BedZed aims to be carbon neutral through the use of renewable energy converted on-site. A combined heat and power unit no larger than a small home will meet all theenergy demand, fuelled by arboricultural arisings from Croydon Council’s parkmanagement (which would otherwise go to landfill). The CHP unit has been sized tosupply the entire heat demand of BedZED and the average electricity demand. At timeselectricity will be exported to the grid, to be retrieved during periods of peak demandwhen the CHP electrical output is insufficient. The CHP plant uses a gasificationprocess with a reciprocating gas engine (paragraph 3.15). It is currently the subject of astart-up programme to achieve reliable operation.


Classification as waste

2.72 Forestry materials, municipal arisings and straw are all secondary products; consequentlysome of these materials might fall under the legal definition of waste. The classification of amaterial as a waste depends on whether it has been discarded or is intended or required tobe discarded regardless of whether there is a market for it as a product58.

2.73 In broad terms, the ramifications of materials being designated as wastes impact largely ontheir transportation. Waste transfer notes must accompany waste materials during transit.As the disposal of these materials is current practice, existing transport arrangementsshould already be in compliance with waste regulations where necessary.

2.74 The classification of these materials as waste need not affect their use as a fuel. Plants thatare fuelled by virgin, untreated wood are excluded from the Waste Incineration Directive59.This means that biomass plants burning municipal arisings or forestry wastes either alone orwith energy crops or co-fired with coal should not need to be classified as wasteincinerators. However, we recommend that all potential biomass schemes confirm thelegal status of their operations on a case-by-case basis.

2.75 Separate from the legal question is the issue of public antipathy to the processing of wastein their neighbourhood. It has been reported60 that certain biomass stations have met withopposition when local residents have become concerned that the plant may be used as awaste processing plant in the future, even when this was not in the project plan. It may beeasier to promote wood gasification technologies that require a homogenous fuel that isclearly distinguishable from waste; but with the development of advanced technologiessuch as pyrolysis that can accommodate very heterogeneous fuel sources, this is likely tobecome an increasingly prominent issue. It is important for acceptability that biomassplants are kept distinct and separate from waste disposal operations; this will only beachieved if operators are scrupulous and transparent about the source of their fuel.

Conclusions2.76 The Forestry Commission has calculated that about 3.1 million odt/y of wood-derived fuel

could currently be made available in the UK61. This includes forestry materials, sawmill co-product, municipal arisings and energy crops (but not straw). This is equivalent to 440MWof electricity (at a conversion rate of 20% in an electrical output only plant), which is abouthalf of the UK’s commitment to electricity production from biomass, even withoutadditional planting of energy crops. The same amount of fuel could also produce some1400MW of heat (assuming 85% total efficiency). This assumes full and easy access to all ofthe UK’s current biomass resource without competition for these materials from otherindustries. If competition for this wood from other industries is taken into account, anestimated 1.3 million odt/y could be made be available; this is a sufficient resource toinitiate a sizeable biomass for energy sector, and it is available now.

2.77 The biomass for energy chain is currently disjointed and there is insufficientcommunication between the stakeholders involved. We recommend that a new

government/industry forum should be established, consisting of representatives fromall parts of the biomass for energy supply chain, including farmers, transporters,generators, construction companies, local councils and central government policymakers. The forum would allow its members to identify problems, share solutions andexperiences and make recommendations on improving the effectiveness of biomassenergy policy. Currently the process of establishing schemes is fragmented and relies to agreat extent on local knowledge and enthusiasm and the drive of a few local entrepreneurs.Setting up a discussion forum would allow knowledge and experience to be shared to thebenefit of all, and produce policy recommendations to enable biomass energy to bepromoted more effectively.



CHAPTER 3 - GENERATION USING BIOMASS FUELS

General Principles3.1 Biomass can be converted into energy by simple combustion, by co-firing with other fuels

or through some intermediate process such as gasificationii. The energy produced can beelectrical power, heat or both (combined heat and power, or CHP). The advantage ofutilising heat as well as or instead of electrical power is the marked improvement ofconversion efficiency - electrical generation has a typical efficiency of around 30%, but ifheat is used efficiencies can rise to more than 85%. This chapter describes thesetechnologies, and considers the amount and types of generation that would be needed tomeet the renewable targets discussed in chapter 1 (paragraph 1.2).

3.2 In each type of plant, the overall reaction for a fuel of mean composition Cx Hy Oz is

Cx Hy Oz + (x+y/4-z/2)O2 x CO2 + (y/2) H2O

The total energy released by this reaction is independent of whether the fuel is burned in acombustion plant, pyrolysed (i.e. heated to decompose the fuel) or gasified (i.e. heated in a flow of a gas, usually air or steam). If the gas and char from pyrolysis or gasification are then burned, the overall reaction is the same as the above; the differences inperformances between combustion and pyrolysis or gasification lie in the way in which theheat is released and utilised.

3.3 Biomass differs from other fuels in several respects, of which two are particularly significantfor heat, CHP or power plants using biomass. The calorific value - i.e. the heat released byburning a specified mass of fuel- is relatively low. Furthermore, the water content of thecombustion gases is relatively high, both because of the hydrogen present in the fuel (seeabove) and because most biomass fuels contain some degree of moisture which evaporateswhen the fuel is burnediii. To recover the energy retained in the water vapour, it is necessaryto use a condensing heat exchanger which converts the water vapour to liquid and recoversthe latent heat of evaporation; this is currently considered an undesirable degree ofcomplication for simple heat and simple CHP plants. However, the overall efficiency isgenerally improved if the biomass is dried before firing, to reduce the water content of thecombustion gases.

ii Some types of biomass can be converted to energy through other means, such as anaerobic digestionto produce methane or fermentation to produce ethanol. These methods are not well suited to thelignocellulosic materials being considered here and are therefore not included in this report.

iii Two measures of calorific value are used: the Gross Calorific Value (GCV, or higher heating value),which measures the heat released when the fuel is burnt and the water is condensed out of thecombustion gases as a liquid and the Net Calorific Value (NCV, or lower heating value), whichmeasures heat release on the basis that the water remains in the vapour phase. The difference betweenGCV and NCV is higher for biomass than most other fuels, and is widened by increasing moisturecontent.

Heat generation

Description

3.4 The simplest kind of process,a plant that provides heatoutput only, is shownschematically in Figure 3-I.The fuel is burned with air in acombustion chamberiv. Thehot gases produced bycombustion pass into a heatexchanger, where they cooland transfer heat to anotherfluid. In the case of a heatingplant, such as for districtheating, this fluid is water thatis pumped through the heatexchanger and circulated todistribute the heat. Thecooled gases are then cleanedto remove particulates andother pollutants before beingemitted to the atmospherethrough a chimney or stack. Typically up to 90% of the Net Calorific Value of the fuel canbe recovered as heat; the proportion is higher (and can exceed 100%!) if a condensing heatexchanger is used.

3.5 Most of the non-combustible part of the fuel - primarily minerals - leaves the combustionchamber as bottom ash. Finer particles are conveyed out of the combustor and removed inthe gas cleaning stage, along with any material injected to clean the gases, as fly ash. Bottomash and fly ash are commonly handled and disposed of separately.

Practical application

3.6 Heat-only applications for biomass are constrained to locations where biomass fuel isavailable and a market for the heat exists. At present this makes them particularly suited,but not limited, to rural areas without access to the gas grid. These areas otherwise have toresort to costly and polluting oil-fired heaters, electric heating or older wood stoves whichare usually inconvenient and inefficient. The use of locally produced materials could alsohelp with rural regeneration through investment and employment opportunities andprovide an alternative market for sectors such as forestry (paragraph 2.59).


Figure 3-1 ‘Heat only’ combustion plant

iv A range of possible combustion chamber configurations is available but, for the sake of simplicity,this kind of detail will not be considered here; nor will the various detailed refinements which can beemployed to improve the efficiency of any of the general processes be discussed.

To stack

Gas cleaning Fly ash

Bottomash

Cool water

Hot water

Heatexchanger

Fuel

Air

Combustionchamber


3.7 Wood from forest management seems therefore to be a particularly suitable fuel for heatproducing plants. The college of West Dean in Sussex has operated a successful exampleof this type of development since 1980. Thinnings and other surplus wood arising fromthe management of woodland on the college estate fuel the heating system for thecollege. This provides both an economic incentive to maintain the woodland and asubstantial cost saving on the college’s fuel bills. Further details of this scheme are inAppendix B.

3.8 Another example of a small-scale wood-fuelled heat facility is a community housingassociation in Lochgilphead in Scotland. A 460kW boiler, powered by locally producedwood chips and by-product from a nearby sawmill, heats 50 one and two storey houses anda respite home.

3.9 There does appear to be emerging government recognition of the need to providesupport to renewable sources of heat. Defra has recently awarded £16m in grants to anumber of energy saving and heating schemes. The largest recipient was Leicester CityCouncil, which was awarded £5.1m for a citywide community heating system. The firstphase will link Leicester University, four housing estates and sixteen council-ownedbuildings. The scheme is not entirely biomass-fuelled but it contains some biomasselements (case study 1, Appendix B). Urban schemes such as this can be less suited toentirely biomass-fuelled schemes as the immediate availability of the materials is limitedto management of urban green spaces and biomass from the surrounding countryside.Other fuels may therefore be necessary to supplement biomass; at least until the supplyinfrastructure develops.62

Chipper and storage shed

Combined heat and power

Description

3.10 For generation of electricity as well as heat, the plant requires a generator driven either bythe combustion gases or by some other working fluid. Figure 3-II shows a steam cycle(reduced to its bare essentials). The hot combustion gases pass into a boiler where water isevaporated to produce high-pressure steam. The steam passes through a steam turbine thatdrives the electrical generator. On leaving the turbine at lower pressure, the steam iscondensed by heat exchange with cold water, and then pumped back up to the higherworking pressure. Thus the steam cycle is closed; water is only added to compensate fordeliberate venting of the steam or leaks from the steam cycle. On leaving the boiler, thecombustion gases are still at a temperature above that at which they are vented. They cantherefore be cooled further by transferring heat to circulating water, before cleaning andemitting to the atmosphere. Bottom ash and fly ash are produced as in a heat-only plant(paragraph 3.5).

3.11 The kind of plant shown in Figure 3-II is capable of flexible operation to vary the ratio ofheat to electrical output. To maximise heat output, the turbine can be bypassed so that thesteam goes straight to the condenser and the plant operates in “heat only” mode. Howeverit is then possible to bring the turbine into operation if electrical output is needed to follow demand or support intermittent supply from other renewables. If particularly rapid response is needed, the turbine can be partially bypassed but allowed to rotatewithout driving the electricalgenerator. Using CHP plantin this way leads to verymuch lower energy penaltythan using electricity-onlyplant as “spinning reserve” tosupply short-term increasesin electrical demand.

3.12 This kind of process is usedfor relatively large scale CHPplant: it provides both heat(to water which can becirculated for heatingpurposes) and electricaloutput. Steam cycles aremost efficient at relativelylarge scales, and the processin Figure 3-II is used in large-scale CHP plants of the typeused in urban installations inNorthern Europe. This kindof process is also used in


Gascleaning

Fly ash

Bottomash

Cool water

Heated water

Fuel

Air

Combustionchamber

Hotwater

Coldwater

water

Condenser

Steam

TurbineElectrical

generator

Heatexchanger

Boiler

To stack

Figure 3-II Combined heat and Power(CHP) plant, using steam cycle for co-generation


large-scale coal-fired electricity generating stations in the UK, where the heat transferred tocooling water from the steam circuit is dissipated by evaporating some of the cooling waterin cooling towers that are a familiar sight at UK electricity generating stations. It is also usedin some biomass-fired electrical generation plants, such as the Fibrowatt plant at Thetford63

or the straw-fired plant at Ely64.

3.13 With a steam cycle, the proportion of the calorific value of the fuel that can be converted toelectrical output is limited by the temperatures in the steam cycle, most critically by thesteam temperature at entry to the turbine ( Box 3A). A modern coal-fired combustion planttypically has an efficiency of about 40% in converting the energy content of the fuel toelectricity. Biomass-fired plants are typically smaller; they also give combustion gases atlower temperatures (paragraph 3.3) so that very high steam temperatures cannot beachieved. Consequently while their overall efficiency, including the production of heat andelectricity, can be high (typically 80% or more) their electrical conversion efficiency islower, and maybe of around 10% for small units. To achieve higher electrical efficiency - i.e.higher Power Efficiency in the case of CHP plant - it is therefore necessary to dispense withthe steam cycle and use instead a gas turbine or gas engine. Rather than simply beingburned, the fuel must now be gasified or pyrolysed.

3.14 In a gasification process, air (or sometimes steam) is blown through the fuel to produce acombustible gas (mainly carbon monoxide and hydrogen). A mixture of air and steam maybe used to control the temperature in the gasifier. Pyrolysis involves heating the fuelwithout air or steam, to decompose it and drive off volatile combustible gases. Pyrolysisinevitably leaves a carbon-rich char which may be burned or gasified. Gasification leavesmuch smaller proportions of residual char.

3.15 Figure 3-III shows schematicallya gasification process. The gasproduced by gasifying the fuel isburned with air and the hotpressurised combustion gasesare passed into a gas turbine.Because the turbine inlettemperature can be higher, theproportion of the heat releasedthat is converted to electricity ishigher (Box 3A). Very largegasification plants may operateat high pressure, to furtherincrease the efficiency ofelectricity generation. However,in order to protect the turbinefrom corrosion and erosion, thegases must be cleaned beforeentering the turbine. Gascleaning may be done on the

Fuel

Gascleaning

Air orsteam

Air

Gasturbine

Electricalgenerator

To stack

Fly ash

Cool water

Hot water

Heatexchanger

Combustionchamber

Gasifier

Bottom ashand char

Figure 3-III Combined heat and Power(CHP) plant, using gas turbine for co-generation

fuel gas before final combustion, as in Figure 3-III, or may sometimes be applied aftercombustion. The gas turbine drives the electrical generator directly. Heat is recoveredfrom the hot gases after the gas turbine, to provide the heat output from the CHP plant.The combustion gases can commonly be vented without further cleaning. Both fly ash,and particularly bottom ash, usually contain unburned char and must be handledaccordingly. For example, they may be co-fired with coal in a conventional generatingstation. This type of plant is inevitably more technologically risky than a combustionplant like that in Figure 3-II. It is also capital-intensive and complex, and therefore onlyviable at relatively large scale.

3.16 Small-scale CHP plants require a different approach from either the steam cycle in Figure 3-II or the gasification process in Figure 3-III. The electrical generator is driven not by aturbine but by a reciprocating gas engine, most commonly a modified diesel engine. Ineffect, the combustion chamber and gas turbine in Figure 3-III are combined in the gasengine. It is still necessary to clean the gases before they enter the engine, although therequirements are less stringent than for a plant using a gas turbine. This must be done at theelevated temperature of the fuel gas but not at high pressure, the technology is thereforesimpler. As in Figure 3-III, the heat output is obtained by cooling the exit gases therebyexchanging heat into water that is circulated as the heat supply.

Combined Heat and Power Quality Assurance Scheme

3.17 New CHP facilities may attract government support under the CHP Quality Assurance(CHP QA) scheme. CHP facilities representing significant environmental improvementsmay be exempt from the Climate Change Levy (CCL) provided they meet certain


BOX 3A Efficiency of energy conversion

[Summarised from Box 3A of the Twenty-second Report of the Royal Commission onEnvironmental Pollution: "Energy – The Changing Climate" (2000)]

Although the first law of thermodynamics states that energy can be neither created nordestroyed, different forms of energy are not simply interchangeable. Converting heat towork involves using some form of heat engine (such as the steam cycle in Figure 3-II) inwhich heat is supplied at a high temperature (T1) and leaves at a low temperature (T2). Inthe case of the steam cycle in Figure 3-II, T1 corresponds to the steam temperatureentering the turbine and T2 to that of the water formed from steam in the condenser. Themaximum fraction of the heat entering the heat engine that can be converted to work (i.e.electrical energy in this case) is

ηmax = 1 – (T2/T1) = (T1 -T2)/T1

Thus ηmax increases if T1 is increased. Real generating plants have conversion efficiencysubstantially below this thermodynamic limit.

The fraction of the heat not converted to work (or electricity) leaves the engine as low-gradeheat.


performance standards. This is not relevant to biomass-fired plants, which automaticallyqualify by using a renewable fuel. However, Enhanced Capital Allowances (ECAs) may alsobe claimed based on the plant’s Quality Index (QI), a measure of overall efficiency(paragraph 3.19), and Power Efficiency which is defined as the proportion of the (gross)calorific value of the fuel converted to electrical output.

3.18 Both the Power Efficiency and QI thresholds to qualify for ECAs have been set at levelsintended to encourage biomass-fired CHP, implicitly recognising the particularcharacteristics of biomass specifically that the proportion of the calorific value that can beconverted into electrical output is lower than for other fuels (paragraphs 3.3, 3.13 and Box3A). Plants fuelled solely by biomass must achieve a Power Efficiency of 10% or more andalso reach a required QI threshold, both based on total fuel burned and electricitydespatched over a 12-month period. By comparison CHP units using more conventionalfuels must achieve a power efficiency of 20% plus a more stringent QI threshold.

3.19 The QI is “an indicator of...energy efficiency and environmental performance...relative tothe generation of the same amounts of heat and power by separate alternative means”65. Thedefinition of QI in the CHP QA standard recognises differences between fuels and scales ofoperation, including the particular characteristics of biomass: biomass-fired plant is set athreshold which is very much lower than that for large gas-fired plants, significantly lowerthan for small gas-fired plant and marginally lower even than that for plant fired byalternative fuel gases or biogas.

3.20 Thus the existing CHP QA standard appears to provide incentives for new biomass-firedCHP installations, although they need to be complemented by incentives for renewable heatproduction (see below). The requirement to meet even the 10% threshold for PowerEfficiency calculated for average performance over a year however, could act as a barrier tousing CHP plant as “spinning reserve”. We recommend that the government undertake orcommission a study to investigate whether the existing Power Efficiency standards areappropriate and, if necessary, modify the CHP QA standard to promote the use of CHPas “spinning reserve” to back-up intermittent renewables. The study should also reviewwhether the thresholds should be based on the gross or net calorific value of the fuel (page 30,footnote iii).

Practical application

3.21 CHP plants burning biomass as a fuel are not common in the UK. The BedZEDdevelopment in South London (Box 2D) has a small biomass gasification plant at its centre.Some technical problems have been experienced, primarily with gas cleaning (Figure 3-III),but the indications are that these problems are short-term. Also, the scheme beingdeveloped by Leicester City Council (paragraph 3.9) is likely to include 6MWe of biodiesel-powered CHP in its later stages. There are other examples of CHP plants using biomass orbiofuels, but use of the technology in the UK is far behind deployment in other NorthernEuropean Countries.

3.22 This is partly because output-based government support for renewable energy is onlyavailable for electricity generation (Appendix A) but also because biomass-fired plants are

less easy to operate than, for example, gas-fired. Relatively small heat-only plants can betolerant to fuel inconsistency and moisture but larger plants, and particularly gasificationprocesses operating at high pressure (Figure 3-III), require dry fuel with consistentproperties, including particle size. Fuel preparation and drying then presents an additionalexpense if forest co-products or SRC biomass is to be used. Sawdust or wood-dust pelletsbreak down to give a particularly free-flowing material. Domestic scale plants requireconsistent free-flowing fuel for automatic operation, and therefore many operators andmost domestic users would prefer to use the more costly sawdust pellets than cheaper butless consistent willow chips or forestry residue.

3.23 Although sawdust pellets are becoming an internationally traded commodity, supplychains are not yet sufficiently established in the UK to guarantee a reliable source of fuel.Potential developers may therefore be discouraged from investing in CHP because of thelack of available and consistent fuel. Some developers have resorted to using local forestryresources until supplies of pellets are available but this can cause problems with technologythat is designed for a drier, more homogeneous fuel.

Heat demand and CHP

3.24 The viability of heat and CHP schemes at larger than domestic scale relies on a market forthe heat output, which in effect means that they are tied to a building, a factory or a heat-distribution network. In Scandinavia such networks have been established, and experiencethere shows that a heat distribution network can extend economically for tens of kilometresand reach tens of thousands of homes and other premises. There are over 600 communityheating schemes in the UK, some of which already utilise CHP66. We recommend that thecouncils or organisations that own these networks should be encouraged toincorporate biomass elements using local resources wherever possible when upgradingthe systems.

3.25 There are also possibilities to develop new applications for CHP plants within an emergingbiomass sector. The heat output can be used for drying biomass, for production of pellets tobe utilised in other plants. Production of some biofuels for transport also represents a heatdemand, for example the distillation of bioethanol. This demand can be met by straw-firedCHP.

3.26 For larger biomass power installations of the order of 10MWe and above, finding a 10-30MWth heat demand to enable the plant to run in CHP-mode is less easy today than itwas 10 years ago. The UK has continued to de-industrialise, and there are now fewer single-site heat demands available. In addition, many suitable sites such as petro-chemical plants,airports and car factories already have gas-fired CHP systems in operation. Some sites doremain however, and new opportunities are emerging with significant housing, retail andindustrial park developments. Retail sites find connection to a district heating systemespecially attractive because it removes the need to allocate potentially profitable retailspace to a heat plant.

3.27 Community heating, utilising both existing small and larger systems, as well as developingnew schemes, provides a significant opportunity for biomass heating. For existing schemes,



replacing fossil fuel boilers with biomass heating boilers is a relatively simple andeconomically viable option, subject to an adequate and reliable heat demand and sufficientcapital grants. Bristol City Council is considering this option for a council-owned housingblock currently fuelled by natural gas (case study 4, Appendix B).

3.28 While there is no central database of heat demands in the UK, research for the CommunityEnergy Programme run by EST and the Carbon Trust has begun to map heat demandacross the UK67. These include domestic buildings, hospitals, higher educationalestablishments, factories, warehouses, offices and retail premises, central governmentbuildings (including prisons, Ministry of Defence buildings, and offices), hotels, leisurecentres, and schools.

3.29 The findings of this research have been separated into heat and electricity requirements bysector; this is illustrated in Table 3.1. It demonstrates that hospitals and hotels areimportant opportunities for biomass district heating and CHP, providing stable heatdemand and utilisation levels. Universities, schools and leisure centres provide other goodheat demand levels, while those for offices and warehouses are less attractive. It also

Table 3.1 Fossil fuel use for electricity and heating

Fossil Fuel Use - Electricity Usefor Space Heating

and Domestic Hot Water

Hospitals (kWh/bed) 25,740 7,000

Universities (kWh/full time student) 4,200 1,710

Factories (kWh/m2) 245 471

Local Government Offices (kWh/ m2) 95 39

Commercial Offices (kWh/ m2) 147 95

Retail (kWh/ m2) 185 275

Warehouses (kWh/ m2) 64 81

Hotels (kWh/bedroom) 13,620 6,387

Schools / Further Education (kWh/pupil) 2,583 372

Leisure Centres (MWh) 2,350 650

1 This figure does not include process electricity

illustrates that far more energy is consumed for heating these buildings than for directelectrical requirements. It is therefore logical for heat to be the driver of a CHP facilitywhere there is sufficient demand. Replacing fossil fuel-powered heat therefore offersopportunities for much higher CO2 savings than replacing the electricity. The currentgovernment incentive schemes fail to recognise this despite the fact that this would be anextremely effective way of achieving the CO2 reduction targets that it has set.

3.30 All new housing, office and other building developments provide opportunities forbiomass heating and CHP. All boiler replacements offer similar opportunities, particularlyin areas away from the natural gas grid (paragraph 3.6). At present however, the level ofawareness amongst developers, designers, financiers and users on the potential for biomassenergy is low. Significant informational campaigns are necessary, as well as targetedmarketing programmes for local authority staff and elected members, developers and theprivate sector. With significant new housing developments planned across the UK(paragraph 4.18), as well as new and refurbished hospitals, schools and other publicbuildings, every development where district heating and CHP for both biomass and fossilfuels is not assessed is an opportunity lost for saving CO2 emissions. We recommend thatall new housing schemes and mixed industrial/retail/housing developments shouldassess district heating and CHP opportunities, including the opportunity to use localbiomass fuels. Positive planning policies should require these developments to includebiomass district heating and CHP wherever it is feasible (paragraph 4.19).

3.31 To make both current and additional sites attractive for CHP in future, greater incentiveswill be needed for ‘green heat’, comparable to those for renewable electricity (Appendix A).Whereas green power can attract a price of 6.5-7p/kWh in total, green heat can attract anincome of only 1-1.5p/kWh68. This encourages the development of the less efficient greenelectricity market at the expense of the more efficient green heat market, so that electricityis currently the usual driver for CHP and heat output is often wasted. Heat output needs tobecome a significant driver to promote more widespread use of CHP, especially in plantsthat can be used as “spinning reserve”.

Green heat credit

3.32 It has become clear to us that the most obvious gap in current support schemes is thelack of any mechanism for supporting the generation of renewable heat energy,comparable for example to the RO scheme for renewable electricity. We recommendthat the government introduce such a support mechanism. It could act as a majorstimulus to both biomass heat and biomass CHP, and it is unlikely that these renewableenergy forms will increase significantly without it. The mechanism could be set up alongthe lines of the Renewables Obligation, and oblige current heat suppliers (gas, oil andelectricity) to supply a given proportion of their heat from renewable sources by a set date(for example, 2% by 2010 and 5% by 2020). The Renewable Heat Obligation could eitherrelate only to biomass, or include other technologies such as solar hot water panels; thepercentage obligation would depend on which technologies were included. Certificates ofverification of supply could be administered in a system analogous to the RenewablesObligation Certificate system as Heat Obligation certificates - HOCs.



3.33 We have recommended the introduction of a ‘green heat’ credit as a policy measure that wouldfit naturally with the government’s current policy and actions to promote renewable energy.However, we note that an approach based on taxation of CO2 emissions would promote allrenewable energy sources, would require fewer specific measures and would automaticallypromote heat as well as electrical output. The introduction of the EU-wide emission tradingsystem will favour biomass along with other renewable energy sources, but whether the pricewill be high enough to provide a serious incentive remains uncertain at this stage.

Electricity generation3.34 Unlike heat-only and CHP facilities, operations that generate only electricity avoid the

need to locate generation facilities adjacent to demand. Electrical power lines are cheaper toinstall than heating networks and are more versatile, and where the plant is situated near thenational grid the generator can sell any surplus power on the open market. The cost is theloss of efficiency by not utilising the heat output from the plant. For example, the ForestryCommission has estimated that some 440MW of power would be available from existingbiomass resources (paragraph 2.76) - this would however forfeit 1400MW if the heat wasnot also used. At present only electricity output qualifies for credits under thegovernment’s Renewables Obligation scheme, which is why this has attracted moreinvestment than district heating or CHP (Appendix A). There are two approaches toelectricity-only generation from biomass: gasification and co-firing.

Gasification of energy crops - ARBRE

3.35 The Arable Biomass Renewable Energy (ARBRE) plant at Eggborough in South Yorkshirewas an example of the kind of process shown in Figure 3-III: gasification of the fuelfollowed by combustion into a gas turbine, with high turbine inlet temperature tomaximise the efficiency of conversion to electrical energy. The fuel comprised agriculturalresidues and SRC willow chips. The plant was designed for electrical output only, with theheat dissipated by water evaporation in cooling towers. Some aspects of the project wereoutlined in the Twenty-second Report.

3.36 Although the ARBRE initiative eventually collapsed, it nevertheless illustrated many of theinfrastructure features essential for a successful biomass energy scheme. The ARBREproject involved a group of farmers growing willow and selling it to a dedicated biomassenergy plant with long-term contracts. Kelda (originally Yorkshire Water) was investigatingthe potential for using sewage sludge as a fertiliser.

3.37 The ARBRE plant experienced some technical difficulties, specifically due to deposits thatfouled and ultimately blocked the heat exchangers. These should not have been sufficientto jeopardise the scheme but the investors were unable to underwrite the costs ofcompleting the start-up programme and bringing the plant into full operation. The failureof ARBRE had implications considerably beyond that single operation: Kelda saw it as apotential pilot for a further 10 such plants whose future is now in serious doubt, while theSwedish company from whom the technology had been licensed saw it as an importantdemonstration. But the loss of ARBRE has also shaken the confidence of other investorsand, equally importantly, of the farmers concerned.

3.38 One of the original difficulties at ARBRE lay in securing a stable funding base for thisexperimental project. It was planned and built under the Non-Fossil Fuel Obligation(NFFO), which guaranteed demand and price for the electrical output but ignored thepotential heat output and gave no assistance with the capital expenditure. The RenewablesObligation has now replaced NFFO but nevertheless many of the features of NFFOremain, specifically in focusing on electrical output but giving no credit to heat. The lack ofsuccess so far in introducing this technology seems to be a UK-specific problem, given thesuccess with which biomass energy plants are operating in other Northern European states,and this suggests under-resourcing of this critical pilot stage. ARBRE cost £28m69 to build,but a properly operating plant would generate revenue and would be attractive to investorsif underwritten; it would also lead the way for further investment.

3.39 The government’s emphasis on high-technology, capital intensive plant, concentrating onelectrical output and aiming to maximise the potential export value of the technology(paragraph 1.10), inevitably means that biomass energy will experience a few false starts(such as ARBRE). Furthermore, given that the UK process plant sector shrank to a smallsize some decades ago, most of the equipment is fabricated outside the UK so the potentialexport earnings are limited. The focus should therefore be on establishing the sectorthrough the use of existing, proven technology whilst simultaneously developing newtechnologies and demonstration plants. We recognise the value of innovation but stressthat it must be developed against the backdrop of a secure, stable sector that can operateindependently of these new developments until they are proven; the very successfuldevelopment of the wind sector in Denmark illustrates this approach. Waiting for high-techapproaches to be developed merely delays the development of the entire sector.

3.40 The Bio-Energy Capital Grants Scheme (Appendix A, paragraph A.8) has so far been toofocused on new technologies. We recommend that the scheme is expanded and itsguidelines revised to make clear that its main purpose is to support the installation ofbiomass-based combustion equipment to bring about a large-scale expansion of heat-only and CHP generation from biomass (power-only generation should be excludedon efficiency grounds).

3.41 We recommend that the government underwrite the cost of at least one, but preferablyseveral schemes to demonstrate the commercial viability of medium-scale biomassenergy projects. Future schemes should however be designed to utilise their heatoutput as well as electrical power.

Co-firing

3.42 With slight modification, coal-fired power stations can accept a proportion of processedbiomass (usually as sawdust) blended into the fuel. A number of plants in the UK currentlyco-fire a variety of biomass materials, including that from energy crops, to produceelectricity and consequently qualify for Renewables Obligation Certificates (ROCs).

3.43 Co-firing, unlike the use of biomass on its own, produces net CO2 emissions from thecombustion process, because of the coal in the fuel mix. These emissions are less than if thecoal had been burned alone, but the overall contribution of carbon to the atmosphere is still



positive. Partly because of this the ROC system places limitations on output from co-firingto prevent companies focusing on this one, easier form of renewable energy at the expense ofinvestment in renewable technologies that avoid fossil carbon emissions altogether.

Grades of biomass

3.44 Biomass for co-firing is classified as low-grade or high-grade according to calorific value.Sawdust is low-grade as it has a high moisture level and hence a low net calorific value. It canbe co-fired without drying because it will be mixed with coal, but the heat released pertonne will be less than for drier material. This is not just because part of the mass (themoisture) has no calorific value but also because of the heat consumed in evaporating thewater. High-grade biomass is produced by drying and processing (into pellets, for example),but is more expensive and better suited to domestic heaters and 100% biomass-fuelledoperations (paragraph 3.22).

Blending

3.45 The fuel for co-firing is prepared by blending coal and sawdust. Sawdust already has a highmoisture content (paragraph 3.44) but has a capacity to absorb further water if not keptunder cover. Consequently the capital costs of providing storage for sawdust is high. Thiscould be minimised by providing central facilities for the blending and storing of fuel,servicing several generating facilities. However, Ofgem claims that under current rules fuelthat is blended off-site is not eligible for ROCs. So for now, co-firing plants must blendtheir own fuels on site, or inject coal and biomass to the combustion chamber separately.Therefore, power generators wishing to co-fire must invest in costly storage and blendingfacilities. If they are unable to recoup this capital expenditure by 2016 (when co-firingceases to be eligible for ROCs) they may choose not to co-fire at all. This is a significantobstacle to the development of co-firing.

3.46 We have heard a number of arguments from Ofgem to justify this situation. We have heardconcerns about the difficulty of maintaining audit trails across long distances (somesawdust is imported), about the difficulty of sampling blended fuels to check theircomposition, and even the concern that sawdust will blow away during transport. We arenot convinced by the arguments and consider that the current arrangements for blendingare unnecessarily restrictive. We therefore recommend that possibilities for securearrangements be investigated whereby Ofgem can certify blended fuels for co-firing aseligible for ROCs at sites other than the power station that is going to use them.

Role of co-firing

3.47 Current government policies encourage and reward co-firing of biomass and fossil fuels inexisting power plants, but, correctly in our view, co-firing is treated as a transitional stage in theprocess of replacing fossil fuels that allows a biomass industry and infrastructure to develop.We will return to this point in chapter 4. However, we note that some of the more prominentschemes we have examined that use biomass alone are failing or delayed, albeit for well-understood and rectifiable reasons. The technology might take longer to develop than so faranticipated and the need for co-firing is, therefore, likely to need to remain a part of UK energyproduction for longer than is currently foreseen by government. In particular, the capacity to

replace co-firing with completely biomass-fuelled power production is likely to remain limitedbeyond the 2016 deadline for the end of co-firing. We recommend that the 2006 review of theRenewables Obligation takes this into account when assessing its deadlines.

Environmental implications3.48 Combustion plants of any description have environmental effects, resulting from their

gaseous emissions, solid wastes, physical intrusion, noise and transport. Any strategy thatenvisages the construction of several hundred new wood-burning plants requires a carefulassessment of the consequences of their effects on the physical environment and of thereaction they will engender in people living near them, or who might otherwise be affected.The strategy will need to include arrangements for minimising pollution and intrusion, andgauging and addressing public concerns.

Emissions

3.49 A heat producing plant needs a local heat distribution network servicing its customers. Thiswill usually mean constructing the plant reasonably close to housing or commercial orindustrial premises that can make use of the heat. This implies that particular attentionneeds to be paid to emission control, for reasons both of public and environmental healthand of public acceptability. Gas cleaning and particulate removal technologies are readilyavailable, and would be incorporated into the initial design for new-build facilities.Condensers and re-heaters can be fitted to remove steam, plumes of which are unsightly butdo not otherwise affect the environmental impact.

3.50 The emissions of most concern (Figure 3-IV) are Volatile Organic Compounds (VOCs).Carbon monoxide (CO), nitrogen oxides (NOx), particulate matter (PM), sulphur dioxides(SO2) and chlorinated organics (principally dioxins). In gasification plants, the gas can betreated before combustion to remove VOCs. Carbon monoxide emissions are low if thecombustion conditions are adequately controlled. Lower combustion temperature


0.0

0.2

0.4

0.6

0.8

1.0

1.2

g/kW

h

VOC CO NOx PM SO2 VOC CO NOx PM SO2Biomass Technology Reference Technology

Fuel production

Clean-up

Conversion

Conversion/indirect

Figure 3-IV Regulated pollutant emissions from Swedish CHP plantfuelled with biomass or coal70

VOC Volatile Organic CompoundCO Carbon monoxideNOx Nitrogen oxidesPM Particulate matterSO2 Sulphur dioxide


compared to other fuels (paragraph 3.3) means that the production of nitrogen oxides islower. Well designed and operational gas cleaning equipment filters particulate matter andthereby concentrates heavy metals into the fly ash (paragraph 3.54). The sulphur content ofwood is much lower than coal, leading to much lower sulphur oxide emissions. Thus,compared on the basis of electrical output, biomass leads to generally lower emissions thancoal; example data from Sweden are shown in Figure 3-IV.

3.51 Chlorinated organic emissions can arise if the fuel contains chlorine. Many forms ofbiomass have very low chlorine content, and therefore give rise to very low quantities ofdioxins. However, the presence of chlorine in the biomass can lead to dioxin production.Therefore timber treated with organochlorine wood preservatives, or wood mixed withPVC, should not be used as a source of biomass fuel in the sorts of generators beingdescribed here. Such materials would be classified as waste (paragraph 2.73) and should beburned only in a properly authorised waste incinerator. The combustion of virgin wood willresult in the formation of much lower levels of dioxins, but even these small quantities havethe potential to be significant on the scale of wood burning that would be necessary to meetthe targets for biomass energy that we have proposed. It is important, therefore, to ensurethat wood-burning heat and power plants are designed to reduce dioxin levels to the lowestpracticable level. Guidance on best available technology for firing installations for woodand biomass is being prepared by the Expert Group on Best Available Techniques of theIntergovernmental Negotiating Committee of the Stockholm Convention on PersistentOrganic Pollutants71.

3.52 A modern wood burning plant should, therefore, with careful design, be able to meet all airpollution control standards at reasonable costs. Even so, siting of the plant must be carriedout with care, and in particular it is important that biomass plants should not be located inareas where they would exacerbate existing poor air quality. Plant burning any fuel in aboiler or furnace with a net rated thermal input of 50 megawatts or more is authorised bythe Environment Agency (SEPA in Scotland and the Environment and Heritage Service inNorthern Ireland) under the Integrated Pollution Prevention and Control (IPPC)regulations Part A. All plant involving pyrolysis, gasification or other heat treatment ofcarbonaceous material would also fall under Part A. Plant with a thermal input of between20 and 50 MW would be authorised by local authorities under IPPC Part B73. Emissions ofnitrogen oxides may represent a significant contribution to poorer local air quality. On theother hand, in some areas, heat made available from a biomass plant could displace morepolluting heat sources (paragraph 3.6).

Solid Wastes

3.53 The amount of ash produced when plant material is combusted generally lies between 6-16% of dry weight, although it may be as low as 1%74. Although much of the variation canbe attributed to plant species, growth conditions also play a major role. Apart from heavymetals, considered below and in chapter 2 (paragraph 2.29), the major components of theash are usually potassium and phosphorus. For this reason, wood ash is often used as afertiliser. However, the proportions of these and other substances vary widely, resulting inthe pH of the ash ranging from almost pH neutral to distinctly alkaline. This variation isoften affected by the major nitrogen source used by the plants75.

3.54 Because of their behaviour in combustion plant, some metals exit primarily in the fly ash;this includes metals with high toxicity, including cadmium, mercury and lead. Figure 3-Villustrates this (see also case study 2, Appendix B). The volume of fly ash from the facility ismuch smaller than that of the bottom ash. Therefore the proportion of these metals is verymuch higher in the fly ash than in the biomass. In effect, the process concentrates themetals into the fly ash, which can then be consigned to a sealed landfill. The bottom ashfrom which these metals have been depleted can be returned to the land where the crop isgrown, or put to some other use such as inclusion in cement or other constructionmaterials. This process is illustrated for willow in Figure 3-V using cadmium as an examplebut it could be applied equally to other heavy metals and other energy crops. Long-termbuild-up of metal levels in the soil would depend on continuous addition of a fertiliser witha high heavy metal content - usually sewage sludge. The use of bottom ash or sewage forland conditioning would need to comply with regulatory or advisory limits on metal inputsto soil.

3.55 Co-firing of biomass with coal leads to mixed ash in which the coal minerals dominate. Thiscontains constitiuents that prevent it from being returned to the soil. As a result, the soilused for biomass production may suffer long-term depletion of key elements, notablynitrogen, so that increased inputs of agrochemicals may be needed.

3.56 Bottom ash from certain combustion processes can be used as a construction aggregate - formaking cement or breezeblocks, for example, or returned to the soil as fertiliser. Ash frompower stations and from municipal waste incinerators is used in this way, and this is clearlya more satisfactory way of dealing with ash than landfilling. It is important, though, toensure that fly ash, with its higher metal content, does not find its way into use either as afertiliser or an aggregate.


Cadmium fromsewage orfertiliser

Cadmiumin fuel

Fly ash(most of cadmium)to secure landfill

Cadmiumalreadyin soil

Uptake bywillow

Bottom ash(small amountof cadmium)

used as fertiliser

Figure 3-V Ash recycling

Intrusion

3.57 A programme of construction of new small to medium heat or CHP plants, incorporatedinto new housing or light industry developments, offers an opportunity for sensitive andinnovative design. Modern biomass stations need not be ugly, and it is desirable, if they areto gain public acceptance, that they are well designed. The building needed to house a smallto medium sized installation need not be large or intrusive. The generator at BedZED (Box 2D) is housed in a building the size of a small house, and is incorporated sensitivelyinto the development. The wood-chip store and heat generating plant at West Dean(paragraph 3.7) is the size of a substantial agricultural shed, but sensitive planning hasensured minimal aesthetic impact of the plant; the chimney is camouflaged and wallssympathetic to neighbouring buildings improve the appearance of the plant. At both WestDean and BedZED, potential planning problems were avoided through discussion withthose who would be affected by the building of the plant. The 36MW straw burning plantat Ely, Cambridgeshire incorporated a number of measures to reduce the visual impact ofthe plant76, including sinking the plant to 8m below ground level. The surplus clay removedduring construction was used to build soundproofing landscape features that were plantedwith 12,000 mixed trees and shrubs and this is now used as a public recreational area.

3.58 Generators, particularly those powered by reciprocating engines, are inherently noisy, butto be acceptable to the community the local power plant must be close to silent. It isessential to design a high level of noise control into a scheme from the outset. At WestDean, noise problems were avoided by restricting the chipping to times when it wouldcause minimum disturbance. At BedZED, the plant is located close to the main buildingsbut has been adequately soundproofed so that no noise complaints have been made.

Conclusions3.59 The properties of biomass make it a particularly appropriate fuel for heat and CHP plants.

Technologies for biomass-fired heating plants are well established; applications depend onmatching biomass supply to heat demand. CHP technologies are controllable but furtherdevelopment is needed, particularly for small-scale plant and plant with high efficiency ofconversion to electrical output. Co-firing of biomass with coal in existing generatingstations has an important short- to medium-term role in developing the biomass sector.Biomass plant that are well designed and properly operated are associated with loweremissions than other fuels, notably coal. Handling of the ash, including recycling ofnutrients to the soil, requires attention for any substantial application along withminimising the impacts of traffic movements and the visual impact of the plant itself.

3.60 Government policy should concentrate on the development of the biomass sector in theUK rather than speculative export opportunities. The plethora of existing schemes shouldbe replaced or supplemented by coherent policies to promote efficient heat productionand use, particularly ‘green heat’ from biomass. Unintended barriers to the use of biomass,for example in co-firing, need to be removed.


CHAPTER 4 - MEETING THE TARGET

4.1 To meet the targets recommended in our Twenty-second Report we proposed that between3 and 16 GW should be derived from biomass (paragraph 1.15). In this chapter we calculatethe number of biomass conversion facilities that would be needed to meet this target andconsider sources of wood to fuel them and the land area needed for growing energy cropsduring each of the four stages of development that we recommended in Chapter 2(paragraph 2.41). We also consider transport implications and, perhaps most critically, weinvestigate ways of gauging likely public attitudes to this form of energy and incorporatingvalues into decision-making.

Economics of Biomass

Fuels

Willow

4.2 In appropriate circumstances, an established willow coppice could bring returns equivalentto those from some arable crops while utilising relatively low-grade land. However, theinitial investment required to establish a crop, purchase planting and harvesting machineryand secure a market, can currently be prohibitive. Farmers are unable to grow energy cropswithout both financial assistance and guaranteed demand for the crop. A number ofgovernment schemes offer financial assistance for planting energy crops (Appendix A) butthese are very limited in the extent to which they can provide the necessary security. Thereis potential for these costs to fall, since with larger areas of energy crops, the relativemachinery costs for each farmer will fall, and efficiencies in harvesting and collection willalso improve. Yields are also likely to improve through better management and higheryielding willow stocks, perhaps by 30%. However, cultivating willow and other SRC cropswill continue to be risky for farmers unless the government can bring forward betterarrangements for financial assistance and promoting long-term contracts.

4.3 Assessing the overall economics of energy crops is problematic at this stage of development,due to the limited experience in both growing the crops and utilising them in power orheating systems, (less than 2,000 hectares (ha) of energy crops are currently being grown inthe UK, producing around 17,000 odt of fuel a year). A number of factors are critical inassessing the overall economic viability for farmers of growing the crops. These include:

• Crop yields

• the level of grants available for establishing the crop

• set aside payments for land used

• the costs of maintaining and harvesting the crop

• the market for the fuel and payments made for it

• costs of removing the crop at the end of the growing cycle.



4.4 The establishment grants for energy crops from Defra are between £920 and £1600/ha,depending on the crop and former land-use. In addition, set-aside payments can continueto be claimed. Alternatively 145/ha for energy crops is available from CommonAgricultural Policy (CAP) funds (but the total fund available is restricted and in practicepayments may be significantly lower than this). Scottish farmers qualify for additional set-aside allowances if they use all of this land for energy crop production. Despite thecombination of these funds, there has been slow uptake of energy crops in the UK, mainlydue to the lack of a market for the fuel and long-term farmer security.

4.5 A recent analysis of the potential income over a 16-year period for both willow SRC andmiscanthus suggested that for medium yield land the average annual income would be£187 to £360/ha77. This compares poorly to a wide range of food crops and livestock. Mostof the current energy crops are grown on set-aside land, this payment is important inmaking the economics of energy crops viable. A report for the DTI that reviewed theeconomic case for energy crops in the UK confirms this conclusion, it concluded that:based on current yields, our estimates of the gross margin for the farmer suggest that energy cropproduction is only attractive using set-aside land78. At current yield levels SRC willow is lessattractive than barley, oats or winter wheat. The DTI commissioned a further assessmentthat showed that with a 30% increase in yield, energy crops would be an attractivealternative to barley. Without subsidies an economic case cannot currently be made forenergy crops but carefully designed additional subsidies could encourage further uptake ofenergy crops by UK farmers. The critical issue for farmers is the security of a market for atleast two to three crops. Without that the risks of establishing a crop with a lifetime of 15-20years is too great.

4.6 Planting grants are currently paid in one lump sum after planting. The first harvest takesplace after four years of growth and for these four years farmers will not be receiving anyincome from those areas of land under SRC production except for set-aside payments. Ifguidelines on the planting of different ages and species are followed, farmers should then beable to attain an annual income from the crops. We recommend that Defra considerintroducing growing grants for the first three years of an SRC plantation to improve thefinancial viability of the crop for farmers. We also recommend that the governmentoffer long-term security to farmers by ensuring that should their local market for SRCcollapse, they will be able to receive payments for keeping the crop until the end of the15-20 year SRC lifespan (paragraph 2.38).

4.7 The Commission has received evidence that higher payment levels to farmers wouldmake energy crops more attractive. However, the over-riding conclusion was that thecritical element in improving both the economics and the commitment of farmers toenergy crops was security of demand. We believe that if farmers had confidence that atleast two, and ideally three, crops were guaranteed a market at a reasonable price, manywould make a commitment to the crop. Unlike annual crops, where low prices one yearwould be likely to lead a farmer to planting an alternative crop the next, SRC willow andmiscanthus require commitment to a long-term crop on at least a 16-year cycle. Althoughmiscanthus is on a shorter growing cycle with annual cropping, it is quite difficult toremove the rhizome roots once established so that miscanthus too must be viewed as along-term option.

4.8 This assertion is confirmed by recent initiatives from the UK company Biojoule, part of theAEA Technology Group. Biojoule is seeking to provide fuel for the co-firing market.Biojoule have offered a simple contract to a number of farmers to test this market. The keyingredients of the contract are:

• an agreement to purchase at least two crops with an option on further crops,

• an agreed minimum price, with further financial incentives to increase the yield froma minimum level of 4 odt/ha/year,

• commitment to take on the harvesting and sale of the crop.

This contract was offered to farmers surrounding a large coal-fired power station and over300 ha were offered for energy crop planting in Spring 200579.

Comparative prices of biomass fuels

4.9 Energy crops are relatively expensive compared to other biomass fuels. There are threedistinctive groups and price bands of fuels:

• Waste arisings attract a ‘gate fee’ if sent to landfill instead of being used as a fuel. Coststo the generator are up to £15/odt. These are by far the cheapest fuels and may in factcome at negative cost, depending on transport costs and gate fees.

• Forest residues, timber industry off-cuts and arisings and agricultural residues such asstraw are typically in the range of £15-35/odt. These are ‘medium cost’ fuels, andtransport costs here are quite critical to overall costs. Sawmill and related timberprocessing industry products used on-site would likely be at the lower end of this pricerange.

• Energy Crops, wood pellets and wood chips produced from roundwood and havingto be transported more than 8km are the more expensive fuels. Fuel prices here are inthe range of £40-80/odt but as yields increase and production and distributioninfrastructure develops this would be likely to decrease.

4.10 Energy crops thus cannot currently compete on price against the other two groups ofbiomass fuels. Energy crops do however have the potential to provide very significantvolumes of fuel. In the event of significant growth in the use of biomass for heat and power,resource limitations may be faced for the other fuels. In order to use the dual heat andpower benefits of biomass energy to help reach CO2 reduction ambitions, energy crops willbe needed in significant quantity. As supply increases, prices are likely to drop to a morecompetitive level.

4.11 However, overall, with the exception of mains natural gas, biomass is currently cheaperthan all other competing fuels. Even when set against natural gas, some of the cheaperbiomass fuels can compete successfully (as is shown in the worked example in case studies5 and 6 in Appendix B). Gas prices are also increasing at present, a trend likely to continueover the next few years; hence the balance could shift towards wood heating. Biomass alsooffers the additional benefit of a secure, controllable supply of domestic fuel that is not thecase with other intermittent renewables or imported fossil fuels.



Capital and generation costs

4.12 Compared to fossil fuel heating technologies, biomass plant is more capital intensive by afactor of 2 to 3; savings for a project come through cheaper fuel. While there is a significantpotential for capital cost reductions, this will require large volumes of sales and a reliablesupply chain in the UK. Even with reduced costs due to volume sales, there would still be acapital cost gap between wood heating technologies and current fossil fuel technology.Capital grants are available through several sources (Appendix A) to reduce the impact ofthis higher initial cost but as yet they have been unable to stimulate large-scale take-up ofthe technology.

4.13 Table 4.1 shows the comparative capital costs of biomass and fossil fuel technology forelectricity and heat production. It is evident that biomass heating is cheaper per kWinstalled than any of the power options, but the return from heat sales is correspondinglylow. Biomass power costs are higher for the reasons discussed above.

4.14 For gasification and pyrolysis plant (until recently the technologies favoured by the DTI forcapital and R&D grants), the costs of the plant are speculative as they are still at thedemonstration stage. The only example of a large-scale gasification plant in the UK, forexample, was the ARBRE project, which failed as we have described above (paragraph 3.38).

Table 4.1 Installation costs of generation technology

Technology Size £/kW installed

Biomass Heating >1MWth £70

Biomass Heating >300kWth £100

Biomass Heating <300kWth £200

Gas fired CCGT 150MWe £400

Gas Fired CHP 750kW-1MW £600 - £700

Pulverised Coal Power 600MWe £1,000

Steam Turbine Biomass Power 5MWe - 40MWe £1,400 - £1,800

Gasification Biomass Power 5MWe - 40MWe £1,500 - £2,000

Biomass Power 5MWe - 40MWe £1,800

Pyrolysis Biomass Power 10MW £4,400

4.15 Site-specific capital grants are available for some biomass power stations. Five grants havebeen awarded since February 2003 for plants ranging from 2.5MWe to 23MWe. Most ofthese grants include a requirement to take a growing level of energy crops as a fuel source.However, none of them had definitely gone ahead or received full financial backing byearly March 2004. The CHP Quality Assurance scheme can in principle provide EnhancedCapital Allowances (paragraphs 3.17 - 3.20) but it is not clear whether this has actuallymaterialised.

4.16 While capital grants can help in reducing the high up-front costs of such systems, it seemsthat under current policy conditions only those plant that are able to utilise either verycheap or zero cost fuels (i.e. plants using fuels for which they can charge a gate fee) are likelyto go ahead. Dialogue with industry representatives has indicated that for power plant usingeither forest residues or energy crops, there is a 1-1.8p/kWh gap between the pricechargeable for electrical output and the income necessary for economic viability80.

4.17 The household use of fossil energy currently attracts a 5% rate of VAT. Some energy-efficiency equipment now also attracts that rate. In addition to an increase in capital grantsfor biomass installations, we recommend that the rate of VAT on biomass-generationequipment for final users also be reduced to 5%. This could help to stimulate the take-upof small-scale biomass generation (domestic pellet heaters for example).

Effective markets

4.18 Biomass energy is most economically viable when the heat potential is exploited. This ismost effectively achieved by locating heat and CHP plants so that they can be linked atreasonable cost to heat-distribution networks. This implies that new-build residential areas,hospitals and industrial complexes are the most likely applications for biomass energyfacilities (paragraph 3.29). The Office of the Deputy Prime Minister (ODPM) hasannounced its intention to build almost 1.2 million new homes by 2016 under itsSustainable Communities programme. The Sustainable Communities programme cannotbe truly sustainable without some degree of renewable energy supply. Biomass could be apart of this if the water and land availability for energy crop growth and otherenvironmental factors are favourable. In our view, if the ODPM programme goes aheadthe use of sustainable energy production should be an integral part of the design.

4.19 Distributed heating networks can be incorporated into residential estates most cost-effectively at the initial design stage. The project at Leicester (case study 1, Appendix B)demonstrates this, though the Leicester initiative will also cater for an element of retrofit inexisting premises. Using biomass as a fuel will not always be feasible in all locations.Nevertheless in many new-build situations there will be scope for securing supplies ofbiomass in an environmentally sound way within a reasonable distance. Where this is notpossible, the use of other fuels to power CHP would be more efficient than centralisedelectricity-only generation. Accordingly, we recommend that the ODPM encouragecouncils and developers to incorporate CHP and district heating as standard in all of itsnew-build projects, fuelled by biomass wherever possible. Councils should considerbiomass CHP or district heating as an option in all retrofit projects. To aid this, werecommend that an integrated approach that takes account of all available biomass



resources in a region should be included in the spatial plan for the region81. A newForestry Commission supported website provides relevant information, which shouldprove a useful tool for such an analysisv.

4.20 Further steps will be needed if the full potential of biomass for district heating and CHP is tobe realised. We recommend that financial support be awarded to councils to enable themto investigate the potential for biomass energy in their area. Taking the European Union’sleadvi, underwriting loans for biomass schemes where councils are unable to provide thenecessary investment could enable the first steps towards council-led development of thissector to be taken. This would reduce the pressure on councils to avoid biomass as a marginalrisk project and would also reduce the reliance on local entrepreneurs to drive projectsforward and to invest time and resources in sourcing funding from disparate sources.Government underwriting of loans (or even provision of loans) would reduce lenderuncertainty and increase the opportunities for councils to secure funding for schemes.

4.21 The project at Leicester (case study 1, Appendix B), illustrates a further unintendedfinancial barrier to the development of biomass (and other) projects whose funding derivesfrom a local authority’s housing department. We recommend amending the HousingRevenue Accounting system to allow councils to secure additional investment for districtheating and CHP systems without being penalised in other areas of funding.

4.22 There are over 600 community-heating schemes in the UK, some of which already utiliseCHP82. The councils or organisations that own these networks should be encouraged toincorporate biomass elements using local resources when upgrading the systems. Werecommend that as part of the government/industry forum (recommended inparagraph 2.77) a network of renewable district heating experts should be establishedto enable the transfer of knowledge and expertise from one council to another.

Transport4.23 Traffic required by an installation is a constraint on the uptake of biomass energy. Small

rural roads or streets in urban housing developments are not suitable for large numbers oflorry movements and the siting of a plant must take into account the need to keep to aminimum the increased traffic caused by fuel deliveries.

4.24 Table 4.2 illustrates the different delivery requirements of different scale plants by fueltype83. The table shows that small heating or CHP plants require relatively few deliveries.The Leicester district heating plant, for example, will need only two deliveries per day, fivedays a week and will store sufficient fuel on-site to cover weekends and holidays. Any

v www.woodfuelresource.org.uk

vi Under existing EU legislation there is a Third Party Finance Initiative (TPFI) that underwrites energyloans under a payback scheme. This will be replaced in 2006 by the Energy Services Company (ESCO)directive which will be easier to implement that the TPFI.


Table 4.2 Deliveries required by plant size and fuel type

Plant Truck Deliveries Deliveries Deliveries volume (/day) (/day) (/day)

(m3) wood chips straw bales miscanthus bales

Large scale 120 21 28 17biomasscombustion(30MWe)

Large scale 120 17 23 13biomass gasification(30MWe)

Small scale 120 5 6 4biomass combustion (5MWe)

Small scale 60 1 1 1biomass gasification (500kWe)

Industrial 60 0.5 1 0.5biomass heat (1 MWth)

Co-firing 5% 120 16 22 13biomass (25 MW )

increase in road traffic resulting from the operation of the facility will be an importantfactor in the planning of any new biomass project. Also, over a period when, theCommission believes, road transport should be decreasing84 it is important to ensure thatjourney distances are minimised and to seek alternative modes of fuel delivery.

Based on references above, using density values of 0.15 m3/t for wood chips (Suurs, 2002), 0.11 m3/t forstraw and 0.19 m3/t for miscanthus (Bullard, 1999)


Table 4.3 Comparison of CO2 equivalent emissions from biomass, coaland natural gas to electricity chains (g CO2eq/kWhe)

Production Transport Conversion Clean-up Total

Biomass 59 17 0.7 0.2 77

Coal 97 957 0.04 1054

Gas 15 396 0 411

Carbon dioxide balance

4.25 Below, we discuss the relative economic and environmental costs of different modes oftransport for the various biomass fuels. Transport will add to the CO2 costs of biomass fuelsand this must be offset against the CO2 reductions secured from use of biomass. Table 4.3 shows CO2 equivalent emissions from a willow-fuelled plant, supplied by willow from within a 50km radius. Road transport is assumed, and the equivalent figures for coal and natural gas-fuelled power plants are shown for comparison.

4.26 The table shows that the bulk of the emissions for biomass production occur in theproduction and transportation stage and that these are very high compared to gas.However, these emissions are more than offset by the very low conversion emissions. Thereare also opportunities to reduce production and transport emissions as the biomass sectordevelops; making biomass even more favourable compared to the fossil fuel alternatives.

Transportation of biomass

4.27 Transport costs remain a limiting factor in the price and financial viability of biomass as afuel. The loss of most of the UK’s country railways has forced farmers to resort to roadtransportation for their crops. This is the most expensive mode of transport: the costs andenvironmental impacts are substantially higher for road transport than for rail or ship.These costs are illustrated in Table 4.4 in financial terms and in terms of the relatedemissions.

Plant efficiencies: Biomass 32%, Coal 38%, Natural Gas 52%.

4.28 These figures may seem to indicate that transportation by ship would be the most desirablemethod of distributing biomass; indeed biomass is already shipped around the globe forco-firing or for production of heat and electricity85. These costs, however, do not adequatelyreflect the total costs - even shipped biomass still needs to be transported from the field tothe port and on from the port to the plant, which will require road transportation for farmsand plant not located at ports or railheads. Emissions other than CO2 from shipping arealso a matter of growing concern. The environmental impacts of shipping biomass wouldtherefore extend beyond the emissions data in the table above. It is also worth noting thatdistances over which shipped biomass travels is significantly higher than road or railtransport distances so the cumulative costs will be correspondingly higher.

4.29 Importing biomass reduces the incentive to UK farmers and foresters to diversify into fuelproduction and has implications for security of fuel supply for the UK and for UKagriculture and forestry. For these reasons we have not examined closely the scope forimported wood to be a major source of fuel in the UK, but it may have a short-term role inthe development of the biomass energy sector.

4.30 Because many forestry materials and, in particular, municipal arisings already incurtransport costs, the marginal costs of their transportation to an energy facility are likely to


Table 4.4 Costs and emissions for transportation of biomass

Mode of Fuel Type Transport Cost CO2 equivalent emissionstransport (£/odt/km) (kg/odt/km)

Road SRC (chip) 0.077-0.086 0.18-0.27

Miscanthus (baled) 0.058-0.080

Forest Materials (chip) 0.077-0.086

Straw (baled) 0.102-0.139

Rail SRC (chip) 0.040 0.028-0.048

Miscanthus (baled) 0.028

Forest Materials (chip) 0.036

Straw (baled) 0.04

Ship SRC (chip) 0.010-0.014

Miscanthus (baled) 0.008-0.0011 Sea Waterways

Forest Materials (chip) 0.010-0.014 0.012-0.024 0.022-0.066

Straw (baled) 0.014-0.019


be zero or very low. Also, their dispersed location makes them often more suitable forlocalised district heating or CHP schemes. This means that transport distances and theassociated costs (both economic and environmental), can be kept to a minimum. Themode of transport used for municipal materials in particular is dictated by the practicalitiesof collecting and distributing the materials; in an urban setting road transportation willusually be the only option. Transport costs are therefore more of an issue for thedistribution of dedicated energy crops than forestry or municipal materials.

4.31 As all of these biomass materials have relatively low densities, transport is volume-limited,not weight limited. As a result, the cost per tonne per kilometre varies for differentfeedstocks, due to the difference in density between wood chips, straw bales andmiscanthus bales.

4.32 The use of lorries for transporting the fuel restricts the economic distances over which thefuel can travel. Using the graphs below (4-I and 4-II) it is possible to estimate a maximumeconomical transport distance for the potential biomass fuels. Using this distance it is thenpossible to calculate the economically viable collection radius for the fuelvii and the cropdensity that would be required within that radius to service a power station.

4.33 The resource density is the proportion of land within a specified area that can be used toprovide a fuel. For example, a power facility that is built near a forest will have a highresource density. In contrast a power facility in a city will have a much lower resourcedensity as only small areas of the radius around the installation will be producing fuel (parksthat are interspersed between buildings and roads etc). A higher resource density impliesthat fuel can be sourced closer to the plant, leading to lower transport costs and lowerimpacts for an installation of a given size.

0

20

40

60

80

100

120

140

160

Cos

t (£/

odt/k

m)

0 10 20 30 40 50 60 70 80 90 100

Distance (km)

SRC (min) Straw (min) Forestry residues (min)SRC (max) Straw (max)

MiscanthusForestry residues (max)

Figure 4-I Transport costs of biomass by distance

vii The average journey is 2/3 of the radius

4.34 It is likely that early ventures into energy crop production will be tightly linked to markets,as at ARBRE or West Dean. Bauen86 has calculated mean economic road transportdistances, with maximum acceptable feedstock cost of £60, to be 33-54km for forestryresidues, 28-33km for straw, 30-60km for SRC, and 20km for miscanthus. Thesecorrespond with collection area radii of 50-81 km for forestry residues, 42-50km for straw,45-90km for SRC and 30km for miscanthus (paragraph 4.32). Even using road transport,over these distances the CO2 gain over fossil fuels confirms that biomass is an attractiverenewable energy option. Further, there are few parts of the UK where there are no demandsfor heat or no options for using electricity within 50 km. In most parts of the countrysources of biomass of some sort, whether energy crops, forests, straw or municipal treesurgery, could be developed. It appears that, provided a sensitive approach to vehiclemovements in residential areas is adopted (paragraph 4.23), transport will not be a limitingfactor, especially in the early stages. However, better ways of transporting the material willneed to be adopted as the market matures in order to maximise environmental gains and toavoid damage and nuisance. We therefore recommend that transport demands bereviewed at each of the four stages of the development of energy crop production.

4.35 A significant obstacle to the development of crops for energy in the UK lies in the logisticsof distributing the crops to the generators and subsequently getting the energy to theconsumer. The Biomass Infrastructure Scheme, presently worth £3.5m and awaiting state-aid approval from the European Commission, is intended to help develop the supply chainand market infrastructure for forestry materials, energy crops and straw for energy use bybridging the current gaps between fuel-growers, generators and energy end users; it will aimto bring the stakeholders together and make the movement of all types of biomass andbiomass energy more efficient. The Commission strongly supports the earliest possibleimplementation of this scheme.

4.36 We accept that there will be areas of the UK where one or more of the limiting factors willbe present; these areas will not be suited to biomass generation. This is not a cause forconcern. As stated in chapter 1, biomass is not being proposed as the sole energy solutionfor the UK (paragraph 1.15). The overall contribution from biomass will be a small butsignificant and valuable proportion of UK energy generation and it should be seen as a part


Res

ourc

e de

nsity

30%

25%

20%

15%

10%

5%

0%0 20 40 60 80 100

Large scale combustion (30MWe)Large scale gasification (30MWe)Small scale combustion (5MWe)Small scale gasification (500kWe)Industrial heat (1MW)Co-firing (25MW)

Radius (km)

Figure 4-II Resource densities for biomass stations by collection radius.


of a diverse, integrated energy portfolio. We do stress however that the possibility ofbiomass generation should be investigated at every opportunity to ensure that it is giventhorough consideration wherever applicable.

Energy conversion facilities4.37 The number of facilities required to produce energy at a given rate will depend on the type

of installation, and in particular their size and efficiency. Here we consider two scenariosbased on the types of heat-only or CHP installations discussed in chapter 3:

i Small heat-only

ii Large steam-cycle CHP

iii. Small gasification/pyrolysis unit using a piston engine

iv Large gasification/pyrolysis unit using a turbine

4.38 Table 4.5 illustrates typical energy outputs of these four types of facility, showing the splitbetween electrical and heat output when they are used as CHP units.

4.39 The table also shows, by way of example, the amount of wood required to fuel these plants87

and, if all that wood were to come from energy crops, the area of land needed to grow them.Paragraph 4.34 discussed maximum economic transport distances; on that basis acatchment area with a 50km radius around each plant is assumed, to indicate the percentageof land within that catchment that would be needed for fuel production (Figure 4-II). The

Table 4.5 Energy conversion facilities

Type Efficiency Fuel input Output Wood Land use Resourcedensity

% (MW) Heat Power Total odt/y hectares %(MWth) (MWe) (MW)

Small heat-only 75 1.3 1 0 1 4,056 406 0.2

Large steam-cycle 80 53 30 12 42 170,333 17,033 8.7 CHP

Small gasification/ 75 1.3 0.7 0.3 1 4,056 406 0.2pyrolysis

Large gasification/ 80 49 29 10 39 158,167 15,817 8.1pyrolysis

picture would be complicated where many plants are located within the same catchmentarea, which would very likely be the case with the smaller sized facilities - in this case thepercentage of land required to grow energy crops would be correspondingly higher. Wheresome of the fuel comes from straw or other sources of wood the area required for energycrops would be correspondingly lower. The total amount of land required for theproduction of energy crops across the UK is discussed in paragraphs 4.44 - 4.54, but it canbe seen from the last column of table 4.5 that facilities capable of powering fairly significantconurbations might require resource densities approaching 10% within a 50km radius.

4.40 Table 4.6 illustrates the number and size of facilities that might typically be required by theyears 2020 and 2050 to achieve 16 GW of biomass energy, the upper end of the rangeproposed in the Twenty-second Report (paragraph 1.15). Scenario 1 assumes significantinvestment in small facilities of around 1MW (types i and iii, for example) so that roughly50% of the total biomass energy is from such plants. In Scenario 2 the main emphasis is onthe larger facilities of around 30 MW (types ii and iv), with only 10% of the energy comingfrom smaller units. The use of biomass in large co-firing power stations would markedlydecrease the number of heat-only and CHP plants required by 2020, but this should largelyhave been phased out by 2050.

4.41 Table 4.6 suggests that between 200 and 500 large generation plants of the size of Enköping(case study 3, Appendix B) or ARBRE (paragraphs 3.35-3.38) might be needed, supported bybetween 1,600 and 8,000 small installations, typically of the sort that might be found poweringhospitals, universities or industrial operations; by comparison, in 2002 there were already55,000 wood-burning facilities in Austria. There is little evidence yet of any progress towardsproducing either biomass generating capacity on this scale in the UK or the fuel to power it88.Only seven biomass power generation plants are operational in the UK at presentviii; there istherefore a need for a programme to accelerate the introduction of more plants.


Table 4.6 Numbers of generating facilities required to deliver 16 GW

Year Scenario 1 Scenario 2

1 MW 30 MW Total no. 1 MW 30 MW Total no.

of installations of installations

2020 2783 93 2875 557 167 724

2050 8000 267 8267 1600 480 2080

viii These are plants supported by NFFO and so they do not include heat-only plants. However, onlya small number of heat-only plants are currently operational.

4.42 Three factors need to be addressed if the rate of construction of biomass conversionfacilities is to be accelerated:

• provision of financial underpinning over sensible time frames (paragraphs 4.2 - 4.17);

• securing effective markets for the heat output from the facilities (paragraphs 4.18 - 4.22); and

• engaging the public in the development of the sector (paragraphs 4.64 - 4.72).

Land-take4.43 We consider below the area of land that will be required to supply 16GW of biomass energy.

4.44 As discussed in 3.44, the calorificvalue of wood is very variable,depending in particular on itsmoisture content. Considerationof “oven dried tonnes” (odt)overcomes this to a certainextent but still does not take intoaccount the differences causedby the loss of energy in the latent heat of steam producedduring the combustion process(paragraph 3.3). Uncertainties arecompounded by the large rangeof conversion efficiencies, fromaround 30% in an electricity-onlyplant to above 80% in a CHPfacility.

4.45 With CHP usage, very roughly, 1tonne of wood per year willgenerate on average 2 megawatt-hours of energy. This implies thatthe lower target of 3 gigawatts ofenergy from biomass, would consume wood at a rate of about 13 million tonnes per year.For the higher target, 16 gigawatts, about 70 million tonnes of wood would be required.

4.46 If all the wood for these scenarios was derived from energy crops at an average yearly yield of10 odt per hectare (paragraph 2.14), some 1.3 million hectares of land would have to be usedfor energy crops to deliver the lower target and 7 million hectares for the higher target. To putthese numbers into context, as discussed in chapter 2, there is currently some 17 millionhectares of agricultural holding in the UK. The bulk of this land is classified as grades 3,4 and5, and is of lower value for food production, suggesting that it could be considered for energy


Box 4A Megawatts and hectares

The combustion of a single tonne of woodwill provide a single quantity of energy,measured in megawatt-hours (Box 1A). Theenergy per unit weight is the calorific value ofthe wood (paragraph 3.3).

The rate of combustion of wood (tonnes peryear) determines the rate of production ofenergy, measured in megawatts. Theproportion of this energy that is useable is theconversion efficiency of the generating plant.

The relationship between hectares andmegawatts thus depends on the yield perhectare of the energy crop (tonnes per hectareper year), the calorific value of the biomass(megawatts per tonne) and the conversionefficiency of the generating plant.

crops. However geographical location and ecological considerations might mean that if theupper 16GW target is to be attained through energy crops alone, areas of grade 1 and 2agricultural land would also have to be used. Currently less than 2 thousand hectares ofagricultural land is under energy crop cultivation (paragraph 2.40) and a major change inland use would therefore be required to meet even the lower target.

4.47 As discussed in chapter 2, other sources of biomass could be available to reduce the amountthat needs to be produced from energy crops. These other sources may be particularlyimportant in allowing time for the change in land use required for the production of energycrops as well as reducing their final land-take. Forests, sawmills and municipal treemanagement could provide about 1.3 million tonnes per year this decade (Figure 2-I).Theoretically this could rise to 10 million tonnes per year by 2020, reducing somewhat afterthis. Straw could also be used, with some 21 million tonnes per year potentially availablefrom wheat and barley and 2.5 million tonnes from rape (paragraph 2.25).

4.48 Figure 4-III illustrates one scenario for meeting the higher energy from biomass target of 16gigawatts, by 2050 using forestry products, agricultural wastes and energy crops. The basicassumptions for this figure are that the calorific value of wood is 10 GJ per tonne and that theaverage energy conversion efficiency is 75% (i.e. the biomass is being used in CHP facilities).It is also assumed that the currently available wood from forests and sawmills could allpotentially be used, that this increases to half the amount theoretically available at 2020, andthat it then settles at about twice the currently available level. About one third of the strawcurrently produced is also assumed to be used for biomass energy and it is presumed that thisremains constant in time. Fig.4-III shows the resulting scenario for the total amount ofenergy from wood and straw each year over the period 2005-2050. The requirement forenergy crops is then estimated as the remainder. The figures on the right hand side of thegraph indicate the millions of tonnes of wood or straw required from each source by 2050ix.


2005 2015 2025 2035 20450

4

8

12

16

20

Gig

awat

ts

YearForestry

Straw

Energy crops

GW from biomass

55 Mt

7.5 Mt2.5 Mt

Figure 4-III Scenario for 16 GW of energy from forestry, straw andenergy crops

ix Prior to 2010, the relative contributions of forestry and straw are not defined, but given the assumptionsdescribed above, the potential resources are more than enough to meet the requirements of the energyscenario.

4.49 In this scenario for moving towards 16GW from biomass, energy crops would not beneeded before 2010. The first two stages of the four-stage approach described by Bauen89

and discussed in chapter 2 (paragraph 2.41) and below would continue until 2017 at whichtime forestry, straw and energy crops would provide roughly comparable inputs. After2020, energy crops would become the dominant source.

4.50 Assuming, as before, that 1hectare of land yields 10odt of wood per year, the implied landthat would have to be under energy crop cultivation at any time is indicated by Figure 4-IV.The land required for energy crops would rise from 1 million hectares in 2020 to 5.5 millionhectares in 2050x.

4.51 The figure provides a rough idea of overall demand for land but it does not take intoaccount the need for transport distances to be minimised and the importance of installinggenerating facilities near markets for heat. This will, to a large extent, constrain the source offuel used in any particular location. In some parts of the country, forest wood will not beavailable within a viable distance; if markets for biomass-generated heat are available, theproduction of energy crops will then need to be stimulated. Similarly there will be otherparts of the country where straw or forest wood are the locally available fuels. It seems likelythat sufficient wood could be gathered or grown to meet the 16 GW target, but councilswith a market for biomass-produced heat wishing to stimulate its uptake as recommendedin paragraph 2.48 should assess the strengths of the various sources in their area.

4.52 At each stage it would be prudent to re-evaluate the amounts of wood available from eachsource and the efficiencies of production and use, and use the economic tools discussed in


x If much more optimistic figures of 75% of availability for forest and straw, 20 GJ per tonne calorificvalue, 80% generation efficiency and 15 odt per hectare yield are used, then the 1 million hectares forenergy crops would be sufficient to meet the full 2050 16 GW target.

2005 2015 2025 2035 20450

2

1

3

4

5

6

Mill

ion

hect

ares

Year

Stage 1Stage 2

Stage 3 Land required formodest scenarioStage 4

Figure 4-IV Land-take for energy crops to contribute to 16 GW Biomassenergy by 2050

chapter 2 and 3 to adjust the rate of production of wood. The staged approach would alsoprovide an essential opportunity to track the environmental impacts of the various sourcesof wood and associated combustion plants. There will be gains, such as the increase inbiodiversity expected from willow SRC (paragraph 2.33), sewage disposal opportunities(paragraph 2.28) and, of course, the production of a renewable energy source. The potentialnegative impacts that will need to be closely monitored arise from the landscape issuesdiscussed in chapter 2 (paragraphs 2.30 - 2.32) and the provision of water for energy crops inareas of the country where water is not abundant.

4.53 We recommend that a strategy for increasing energy crop production must include both re-assessment of fuel sources and rigorous impact monitoring, with strategic environmentalassessments, at each stage.

Planning for biomass4.54 Government policy (and the Renewables Obligation in particular) has failed to take

account of the time that is required to establish an energy crop. Using the example of a2,000 MW station that currently co-fires 5% of its fuel as biomass, by 2009, 25% of thisbiomass proportion must be from dedicated energy crops (1.25% of total fuel); if thegenerator chose to continue to fire the same proportion of biomass, this would require30,000 odt of willow SRC. At current yields of 7 odt/ha/y over a three-year harvest cycle(i.e. 21 odt/ha over 3 years), this means that the generator would require the willow fromaround 1,500 hectares of land in 2009.

4.55 These crops would take 4 years to grow, so to be ready for harvesting by the 2009 deadlinethey would need to be planted in the spring of 2005. Farmers plan their land-use ahead oftime because they need to order seeds (or cuttings for willow SRC) and prepare the land(rabbit proof fencing can be expensive and time consuming to erect). This would need tobegin in mid-2004 for everything to be in place for a spring 2005 planting date.

4.56 Willow SRC is eligible for a Defra planting grant, which farmers need to know is guaranteedbefore they order the plants and fencing. The paperwork for these grants takes around 3months. In order to reach the 2005 planting date, applications for planting grants wouldneed to have been submitted no later than April 2004.

4.57 Farming co-operatives may have needed to be established to ensure that enough land wasavailable to produce the wood required. This could easily take 2 months or more to organise,which means they would have had to start making arrangements in early February 2004.

4.58 Once this process has begun it would need to be repeated for at least three years to ensure aharvest every year in the SRC cycle. This could bring a farmers’ co-operative’s total plantingarea to almost 5,000 hectares, and possibly more as the energy crops percentage of co-firingincreases between 2009 and 2016. A land commitment on this scale would requireassurance from the generator that they would purchase the fuel, otherwise farmers wouldnot be eligible for the Defra grants that are dependent on end-user contracts and theywould not be confident to commit that area of land to a crop for an uncertain market.



4.59 Farmers are therefore unable to proceed without a contract from a generator, yet thegenerator is able to benefit from the Renewables Obligation system without anycommitment to a grower. The fear among growers is that generators will co-fire for as longas they are unrestricted in their use of biomass (and can use imports) and then will stop assoon as the energy crop requirement is introduced in 2009.

4.60 The situation is further complicated by the fact that generators are reluctant to offercontracts to growers because they are concerned that the Large Combustion Plant Directive(LCPD) may severely curtail the long-term future of some power stations. Until they knowhow the Directive will affect them, they cannot offer a contract to a biomass supplier. If thistook too long it would be too late for the farmers to plant their coppice. Growers wouldhave required a contract or letter of intent by the end of January 2004 to enable them tosupply sufficient fuel to enable the generator to meet their 2009 RO deadline. As far as wehave been able to establish, this has not happened and the future of energy crops for co-firing is consequently now in doubt. Generators are likely to comply with the LCPDthrough some combination of the fitting of flue gas desulphurisation (FGD) equipment,use of low sulphur coal and adjustment of power-station load factors. It may be that theincome from ROCs gained from the use of co-firing in a number of power stations wouldhelp the generators to fit FGD in one of them. It would then be important, if FGD powerstations had to close, for the FGD station to be able to honour all the contracts to growersthat were outstanding. We recommend that the required methods of accounting andadministration for the ROCs should ensure that this can and does occur.

4.61 The purpose of co-firing is to stimulate the energy crops market; it is currently failing to doso. With the added security of compulsory contracts, supply of energy crops would increase(paragraph 4.7), which in turn should encourage the uptake of biomass schemes other thanco-firing. This will only happen if, as we recommend, the restriction on materials for co-firing is combined with a requirement that the generators confirm their intention to co-fire by awarding long-term contracts to growers without which they should not be ableto qualify for ROCs.

4.62 The combination of policies from different government departments and from Whitehalland Europe are hence working against each other and causing a deadlock in the biomassindustry. We recommend that the government introduce an integrated strategy thatincorporates every part of the supply chain to support and promote a biomass energyindustry in the UK.

Public acceptability

Causes of concern

4.63 A review90 of earlier research in 1998 concluded that the widespread establishment of SRCwas potentially acceptable to most users of the countryside. However, a recent study91 hasidentified that concerns were likely to be about:

• generating plant,

• storage/processing building proposals,

• associated traffic movements,

• visual impacts,

• doubts over the reliability and location of biomass supply,

• lack of benefit for the local community.

4.64 A key problem identified in case studies was the site-specific nature of NFFO contracts.Proposals for such contracts were based on one site, determined in a secretive process, andnot open to subsequent modification. Public consultation was then aimed at persuadingthe public of the correctness of the choice, rather than being a genuine consultation. Newplans should recognise the importance of community involvement in planning decisionsand be genuinely open and flexible. It is essential that uncertainties and different premisesbe explicit in the planning process. A key recommendation of the Commission’s Twenty-first Report, Setting Environmental Standards, was that people’s values should be integratedinto each critical stage of decision-making. These principles should be applied whenplanning any biomass installation. In our Twenty-third Report, Environmental Planning, wemade recommendations on improving procedures and developing new processes for moreeffective and productive public involvement in the development of new schemes.

4.65 With any new-build biomass facility, as with any combustion process, there is also likely tobe public concern about emissions. At an early stage, it is necessary to ensure that the publicin general, and major players such as the environmental groups, are comfortable thatemissions will be satisfactorily controlled and that biomass generation represents acontribution to essential developments in energy provision. Risk estimates, oftenpresented as the objective outcome of a scientific assessment, may involve important butoften obscure assumptions and value judgements. Thus perceptions of risk that divergefrom expert estimates are not necessarily irrational but may well reflect different values from thoseunderlying the expert assessments92. The conflict between the values and risk estimates of localexperts and industry experts has been cited in a number of studies93 as a source ofcontention during the planning stages of biomass facilities.

4.66 The need to minimise the intrusiveness of plant by careful design and location wasdiscussed in chapter 3 (paragraph 3.56). In particular, for plants situated in residential areasthe ensuring ‘ownership’ of theplant by people living near it isessential. This suggests that smallplants serving local communitiesmay be better accepted than largeones that also serve communitiesliving some distance from theplant. A public perception ofbiomass plants is influenced, to adegree, by the existing situation.Plant replacing old, inefficient,polluting oil-fuelled plant (that areused in many off-grid areas) arelikely to cause less concern thanplants that are planned as newinstallations.


Wood chipper and storage shed surrounded by walls and trees,West Dean


4.67 Local public involvement in a scheme is important, and the developer and council willneed to:

• make explicit the local benefits and impacts from the facility,

• ensure that local energy costs are reasonable,

• ensure complete transparency throughout the process,

• demand sensitive design and architecture,

• engender not just openness but involvement.

Role for government

4.68 The acceptance of renewable energy options by the public is important to the success of anyenergy strategy that reduces CO2 emissions to the levels that will stabilise climate change.The government has an interest in engaging public opinion in the debate about renewables,including biomass. There may therefore be a role for Government in assisting thecommunication process leading to the development of individual planning proposals, toensure that public concerns are addressed and that renewable energy strategies are enacted.

4.69 A broad range of opinion should be incorporated into the key stages of design and planningof biomass projects. This is important to ensure that the assessment processes properlyaddress public concerns and do not overlook the importance of incorporating a range ofdifferent perspectives into the design of a scheme and its subsequent implementation. Thiswill require a fully transparent process, with information about biomass energy placed inthe public domain and machinery in place to obtain the views of a broad range of people.In our Twenty-first Report we proposed a conceptual framework for environmental policythat involved several complementary and inter-related components, including inter aliascientific evidence, risk assessment and economic appraisal. We recognised that allcomponents would be characterised by uncertainty or indeterminacy, and might beinfluenced by different interests and beliefs.

4.70 The Office of the Deputy Prime Minister is currently consulting on replacing existingplanning guidance on renewable energy (Planning Policy Guidance note: RenewableEnergy - PPG22). The new consultation document, Planning Policy Statement 22 (PPS22),is much more concise than the document it is proposed to replace, and gives more guidanceon the importance of achieving renewable energy targets and how to address conflicts withother land uses. It highlights the public concerns raised in connection with renewableenergy projects and gives advice on addressing them, whilst achieving the overall renewableenergy objectives. The guidance note remains to be finalised.

4.71 There is more that could be done centrally, however, to initiate and inform debate aboutbiomass energy. We recommend that the network of existing Renewable Energy AdviceCentres should be expanded to increase the level and geographical coverage of theadvice available. Performance incentives should reward those centres that see schemesthrough from advice to installation and operation. Models and Internet displays ofenergy crop plantations and conversion plants and demonstration projects would help.Biomass is not a cheap form of energy; it requires high levels of capital investment and partof this is the cost of establishing that the scheme will be acceptable to the public.


Phased delivery4.72 A gradual approach to the introduction of biomass energy will be needed. The four stages

recommended below will provide a framework within which this gradual approach shouldinclude the introduction of the technology to people who might have a view on itsacceptability, the appraisal (and, from time to time, the re-appraisal) of the availability ofbiomass fuel from the sources we have identified, and rigorous monitoring of theenvironmental impacts of energy crops and energy generating plants.

First stage ( 2004-2012)

4.73 Bauen94 defined this period in terms of a relatively small proportion of set-aside land beingused for energy crops. Figure 4-IV indicates that this might last until 2012, but it could lastconsiderably longer. During this period:

• government grants for the production of biomass, the development of demonstrationconversion facilities and assisting the introduction of district heating schemes shouldbe rationalised;

• government should introduce the concept of energy crops to the public, gaugereactions and ensure that public values are incorporated into future plans;

• guidance should be provided to planning authorities on sensitive design ofinfrastructure, and to farmers on minimising landscape impacts and maximisingbiodiversity gains;

• wood from forests, sawmills and municipal tree management will increasingly be usedas fuel, particularly in co-firing installations, to prove the system.

Second stage (2012-2018)

4.74 During the second stage the area required for energy crops increases up to an areaequivalent to the amount of set-aside land.

• Co-firing is likely to remain a major user of biomass, with increasing numbers of smallCHP plants installed in hospitals, educational establishments andcommercial/industrial premises.

• Local authorities will start to assess biomass resources in their areas and a strategicassessment of the environmental impacts of growing energy crops will be necessary.

• This stage, which will last between 5 and 10 years, is also likely to see the start of asignificant programme of construction of larger (30 MW) biomass CHP plants nearurban conurbations.

Third stage (2018-2025)

4.75 The area required for energy crops increases significantly beyond the amount of land that iscurrently set-aside. This stage might last until about 2025 with the following developments:

• a rolling programme of energy conversion facilities and heat distribution systems willprovide a gradually increasing market for wood;


• farmers will gain confidence and energy crops will become an accepted main crop;

• co-firing will be phased out.

Fourth stage (2025-2050)

4.76 By this stage the programme will have been established. The farming community will becomfortable with energy crops, district-heating schemes will be the norm in new buildresidential and commercial developments and local communities will have a sense ofownership of their local generation plant. The area of land under energy crops increases, upto 2050, to be a significant proportion of total available agricultural land. By this time it willbe important to start examining other transport options, with increasing use of rail todeliver wood to processing and distribution centres.

A strategic approach4.77 This report has shown that the production of the wood, its transportation and its

conversion into energy have to be integrated if investment, efficiency and publicacceptance are to be achieved. Farmers will not grow energy crops, or foresters gather them,unless a market in the form of energy conversion stations exists, and these will not be builtunless there is a market for the heat and electricity they produce - whether through districtheating networks or advantageous electricity prices. The public will not accept thetechnology if they fear unacceptable levels of intrusion into the landscape or reductions inair quality.

4.78 Experience has shown that the introduction of biomass renewable energy systems in theUK will not be easy without considerable planning and a certain amount of seed-corninvestment by government. But equally, experience in other countries shows that biomasscan make a significant contribution to energy supply and that the investments areworthwhile. In this report we have shown that economically and environmentally, biomassenergy could be viable and ought to be pursued, and we have set out a staged approach todelivering the targets for biomass energy proposed in our Twenty-second Report.


CHAPTER 5 - CONCLUSIONS & RECOMMENDATIONS

5.1 In 2000, the Royal Commission on Environmental Pollution published its Twenty-secondReport, Energy - The Changing Climate. The government subsequently accepted our keyrecommendation of a 60% reduction in CO2 emissions by 2050 and stated in the EnergyWhite Paper that the UK should be put on a path towards achieving this reduction. In theTwenty-second Report we explored a number of ways for reaching that target, and the use ofbiomass as a useful source of renewable energy was a significant component of thesescenarios. In this report we have considered the use of biomass further.

5.2 Biomass energy production is close to carbon neutral and has the added advantages overother sources of renewable energy of being controllable and of producing heat; both ofwhich would increase the reliability and the security of the UK’s energy supply. Biomassenergy is well established in several countries around the world - the technology is provenand the benefits demonstrated; but so far, uptake in the UK has been extremely limited.

Conclusions5.3 Sufficient biomass is already available to initiate the development of the sector, in the form

of forestry products and by-products, straw and municipal arisings. Systematic use of thismaterial will have the additional benefits of providing additional income streams forfarmers and foresters, improving forest management, and diverting materials from landfill.In the longer term, the use of biomass for energy will depend at least partially on theproduction of energy crops. This would require a significant change in agricultural land-useby 2050, and we have recommended approaching this change gradually, through fourdistinct stages that provide opportunities for periodic assessment of the environmentalimpacts, the social acceptability and the economic viability of biomass utilisation.

5.4 Biomass conversion technologies are particularly adaptable; the scale, type of fuel and heatto power output ratio can all be varied according to local supply and demand. Distributedgeneration offers opportunities to engage local communities and to develop a sense ofownership of, and responsibility for, localised energy production.

5.5 Existing government support measures for biomass energy are complex and can conflictwith each other. In this report we propose a rationalisation of government policy andsuggest ways of making policy more effective in encouraging the development of a biomassenergy infrastructure. We also make recommendations for sharing experience and expertisebetween stakeholders in the biomass sector, and we describe the agronomies andtechnologies that are currently either available or in development.

5.6 There is a significant gap in government energy policy regarding heat production. Usingheat instead of, or as well as, electrical energy could increase conversion efficienciessubstantially - from typically 30% to around 80%. Biomass can be a reliable, controllablesource of both heat and power and the utilisation of this additional benefit shouldtherefore to be central to biomass exploitation.


Recommendations5.7 We have made recommendations in this report that encompass a wide range of measures

that could be introduced to stimulate the biomass market and make a significantcontribution to climate change strategies in the UK:

Fuel production and distribution

5.8 The grant system for farmers should be dependent on farmers meeting set environmentalstandards in landscape, biodiversity and water assessment when planning and plantingenergy crops (paragraph 2.46). In return, the grant payments should reflect fully thebiodiversity value of these crops (paragraph 2.38). Farmers should be awarded greaterflexibility in selecting energy crops and this should not be penalised by a restrictive grantsregime (paragraph 2.18).

5.9 Farmer security needs to be improved to encourage the planting of long-term energy crops.Requiring generators to provide long-term contracts to growers to enable them to qualifyfor ROCs would provide the necessary security for farmers and would introduce equitybetween key stakeholders in the ROC system (paragraph 4.61). The government may alsowish to consider offering guaranteed markets and prices to farmers to increase security untilthe markets are more developed (paragraphs 4.6 - 4.7).

5.10 The Commission supports the earliest possible implementation of the BiomassInfrastructure Scheme to improve farmer access to markets and investor confidence in thesector (paragraph 4.35).

Technology

5.11 Biomass energy technology, like others, must comply with environmental standards.Planning should be sensitively designed and all possible technical measures should beutilised to reduce noise and emissions and to increase efficiency and therefore reducetransportation of fuel. Solid wastes, fly ash in particular, will need to be disposed ofcarefully and appropriately (paragraphs 3.48 - 3.57).

5.12 The focus should be on establishing the sector through the use of existing, proventechnology whilst simultaneously developing new technologies and demonstration plants.The Bio-Energy Capital Grants Scheme should be expanded and its guidelines revised tomake clear that its main purpose is to support the installation of biomass-based combustionequipment to bring about a large-scale expansion of heat-only and CHP generation (power-only generation should be excluded on efficiency grounds) from biomass. We recommendthat the government underwrite the cost of at least one but preferably several schemes todemonstrate the commercial viability of medium-scale biomass energy projects. Futureschemes should however be designed to utilise their heat output as well as electrical power(paragraphs 3.39 - 3.41).


Generation of energy

5.13 Possibilities for secure arrangements should be investigated whereby Ofgem can certifyblended fuels for co-firing as eligible for ROCs at sites other than the power station that isgoing to use them. Review of the ROC scheme should consider the delay in energy cropproduction and how this affects current deadlines (paragraphs 3.46 - 3.47).

5.14 The scope for biomass as a source of renewable heat needs further investigation. Theintroduction of a green heat credit would help to raise the profile and profitability ofschemes that use biomass. It would also encourage better efficiency in energy generationand increase the CO2 savings of the UK energy sector (paragraph 3.32).

5.15 Biomass energy should be considered positively in all new-build and retrofit projects. Theassumption should be in favour of biomass energy in all projects; construction companiesand councils should have to justify any decision not to adopt this option (paragraphs 3.24,4.18 - 4.19).

Strategy

5.16 The planning process should be open, transparent, flexible and inclusive. Localcommunities should be involved in every stage of planning a new biomass plant and local‘ownership’ should be encouraged in all new-build projects (paragraphs 4.63 - 4.69).

5.17 A biomass forum should be established to encourage the sharing of ideas and expertise andto provide support to early-stage projects. This forum should be open to all stakeholdersincluding farmers, construction companies, local councils, power generators andenvironmental NGOs (paragraphs 2.77, 4.22).

5.18 The four-stage approach set out in this report allows for periodical review and reaction tochanges brought about by the development of a biomass sector (paragraphs 4.73, 4.76).Because of the considerable uncertainties that exist in this early stage of biomassdevelopment in the UK, a strategy for increasing energy crop production must includeboth regular assessment of fuel sources and rigorous monitoring of impacts, withassessments of environmental consequences at each stage.

5.19 We invite the government to improve measures to encourage biomass as a long-term, stableand secure option for renewable energy. We particularly encourage the government toconduct an investigation into the potential for green heat production and the use of policymeasures outlined in this study to make real progress towards the establishment of thissector. The opportunities for using biomass to reach CO2 reduction targets for the UK aresignificant and all biomass policy should be aimed primarily at this goal.


APPENDIX A – POLICIES TO SUPPORT BIOMASS –DESCRIPTION OF CURRENT SCHEMES

A.1 Public support for biomass may be given to the provider of the fuel or to the generator ofthe energy. This could be an individual household, a single institution (such as a school orhospital), a community comprising both households and institutions, or an industrialestate. The energy may be in the form of heat, power, combined heat and power (CHP) orelectricity from co-firing in coal-fired power stations. The support may be applied to thegrowing, processing or distribution of the fuel, to the purchase of the generation equipmentor to the flow of final energy itself.

A.2 It will be seen that current support schemes are quite complex. There is a growing networkof Renewable Energy Advice Centres (growing out of the Energy Efficiency AdviceCentres) to give advice on the renewable energy measures that can be taken and the grantsavailable. The commentary that follows gives some further details of the schemes.

Support for Fuel Provision

A.3 There are four broad types of biomass fuel: forestry materials, where the fuel is a by-productof other forestry activities; energy crops, such as short-rotation coppice (SRC) andmiscanthus, where the crop is grown specifically for energy generation purposes;agricultural residues, such as straw or chicken litter; and imported biomass, for use in co-firing. There is currently no support for imported biomass for co-firing although there maybe for the energy generated from it (paragraph A.14).

A.4 The Biomass Infrastructure Scheme (presently worth £3.5m and awaiting state-aid approvalfrom the European Commission) is intended to help develop the supply chain (and marketinfrastructure) for woodfuel (forestry materials and energy crops) and straw for energy use.The Scheme is intended to bridge the current gap between fuel-growers and energy end- users.

A.5 The Woodland Grant Scheme (WGS) is part of the England Rural DevelopmentProgramme (ERDP), in Scotland there is the Scottish Forestry Grants Scheme (SFGS). Theschemes provide grants for managing existing woodland and for planting new woodland, asa result of which forestry material may be made available for energy use. The WGS is worth£139 million over the seven years from 2000 to 2006. The Farm Woodland PremiumScheme, also part of the ERDP and only available in conjunction with the WGS, providesannual payments to farmers to compensate for agricultural income foregone as a result offorest planting. This scheme is worth £77 million over the same seven-year period.

A.6 The Energy Crops Scheme provides grants of between £920 and £1600 per hectare(depending on the crop and former land-use) and is worth £29m over 2000-2006, tosupport the establishment of energy crops, provided that growers have a contract for theenergy end-use for their crop, and they adhere to certain conditions. In addition, grants ofup to 50% of costs are available for setting up and operating Willow SRC (not other energy

crops) producer groups, and to help with the purchase of planting and harvestingmachinery to be held in common for the group.

A.7 The EU Common Agricultural Policy (CAP) provides two kinds of support for energycrops. Energy crops may be grown on set-aside land, and on non-set-aside agricultural landthey may receive a grant under the CAP of 145 per hectare (though this is reduced pro rataif the total qualifying acreage in the EU exceeds 1.5m hectares).

Support for Generation Equipment

A.8 The Bio-Energy Capital Grants Scheme is a UK-wide scheme worth up to £66m andprovides up to 40% of the costs of generation equipment in eligible projects. Most of thesupport has so far been applied to high-technology equipment (for example, gasification),but in principle any equipment generating heat, power or CHP from biomass is eligible.Projects using energy crops are given priority. The funding is available to public sectororganisations for capital funding of district heating schemes.

A.9 The Clear Skies Initiative is worth £10m and supports households and communities inEngland, Wales and Northern Ireland in the installation of renewables technologies,including biomass heat (also solar hot-water panels and solar PV). There is a similar ScottishCommunity and Householders Initiative, worth £3.7m over three years to 2006.

A.10 Biomass-fuelled boilers are eligible under the Enhanced Capital Allowances (ECAs)scheme, through which firms can write off 100% of the equipment costs against theirtaxable profits in the first year of investment. Equipment for ‘good-quality’ CHP(paragraphs 3.17 –3.20) is also eligible for ECAs.

A.11 The Community Energy Programme is worth £50m and supports public-sector districtheating schemes through capital grants. So far only one of thirty-two grants (which haveused £16m of the £50m available) is for a biomass scheme, but this could expand.

A.12 The Carbon Trust provides finance for carbon-reduction projects, spending £5m on R, D&D funding in this area in 2003. It can also make equity investments in more matureprojects. Eligible projects include the generation of heat from biomass, although suchschemes have been awarded only 1% of the total fund to date.

A.13 The Community Renewables Initiative, worth £1m and funded by the CountrysideAgency, provides information and facilitation to stimulate community-based partnershipsto promote renewables.

Support of Energy Flows

A.14 Renewable electricity generation, including that from biomass (and the electricitycomponent from CHP) is eligible for Renewables Obligation Certificates (ROCs) and canreceive Levy Exemption Certificates (LECs) in respect of the Climate Change Levy(paragraphs 3.17 – 3.20). ROCs and LECs are also available in respect of the biomass inputwhen it is co-fired in conventional power stations, in an effort to establish biomass supplychains. This support is planned to be phased out by 2016.


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Table A.1 Summary of policies to support biomass


APPENDIX B – CASE STUDIES

Case study 1: Leicester City Council - district heating scheme112

Background

B.1 Leicester City Council has a long-established history of providing district heating (DH). Itsfirst DH system was established in 1953 and was fuelled by locally-sourced coal. The coalpits in the area have since closed and the Council is concerned about security of energysupply and the continued use of fossil fuels and their associated CO2 output.

B.2 The citywide community heating system utilising CHP was conceived in 1987 following agovernment-funded study. The Climate Change Review in 1989 resulted in the 1990Action Plan. This 35-year energy reduction plan set out to reduce energy use by 50% andstipulated that harmful emission levels should be reduced in Leicester by the year 2025.This made Leicester the first UK city council to implement a green energy strategy and itwas designated Britain’s first Environment City where a commitment was made to source20% of its energy supply from renewable energy by 2020. The Council saw biomass forenergy as a key way of meeting this target.

Finance

B.3 The Energy Centre team at Leicester City Council have secured £5.1 million of fundingfrom the government’s Community Energy Programme and £2.6 million from the EastMidlands Development Agency towards the costs of phase one of the scheme (£26.1million), and are seeking additional funding from the private sector. The total project costis estimated at £64 million over 8 years and they will have to seek further public sector andEuropean funding as well as funding from other sources.

B.4 Such a scheme has to compete with other demands on Council funds, and is disfavoured bythe way Local Authority funding is currently controlled. As part of Housing Departmentspending, heating schemes fall under the Housing Revenue Accounts system which issubject to tight restrictions and to the “additionality” rule which means that any additionalfunding must be used to release funds for expenditure elsewhere. Despite this, it has provedpossible (albeit difficult) to attract external investment in Leicester because the fact that themain investor, i.e. the Council, cannot go bankrupt makes the enterprise less risky.

Tenants

B.5 The control of the community heating systems by the energy section of the City Councilremoves the responsibility for maintenance of individual heating systems away from thehousing department and housing associations where they are connected to the communityheating system. It also benefits the tenants in two key ways; the heat provision is part of the


rent payment which is VAT free; and the Council, as the heat provider, is encouraged toupgrade the insulation of their housing stock to reduce heat demand. In effect, the Councilor an agent established by the Council acts as an Energy Service Company (ESCO).

B.6 In ‘right-to-buy’ sales of council properties fitted with community heating systems, theowner reserves the right to change the heating system if desired. If the property remains thatof the Council or is handed to a Housing Association, tenants do not have the right tochange the heating systems. Most right-to-buy tenants opt to keep the installed biomassheating system as it is more cost effective than installing an individual boiler and it providesheat at a lower running cost. It also means that they can benefit from council maintenanceand upgrades at little extra cost.

Fuel

B.7 Woodchip biomass will be used in the new plant. 70% of the woodchip needed will beobtained from forests surrounding the city and within the East Midland region. The other30% will be collected from the city centre where 5,000 tons of municipal arisings aregenerated each year and stockpiled on Council land. The plan is for local farmers to collectthe arisings and chip them for use in the biomass plant. 70% of these municipal materialswill be unsuitable for energy uses and will be composted by the farmers, the other 30% willbe delivered back to the biomass plant for fuel. This will save the council £15 a tonne inlandfill charges and will provide an income stream for farmers. The farmers involved in thisscheme will be collecting the rest of the wood from forests and woodland aroundLeicestershire and within the East Midlands. It is anticipated that sufficient fuel can besourced within a 10-mile radius of Leicestershire, which will keep transport distances to aminimum.

Planning

B.8 The proposed scheme has not received any complaints including objections to planningissues. Building on an existing power generation site and incorporating technological bestpractice to minimise emissions and plume formation have probably enhanced itsacceptability. It is anticipated that the scheme will be able to meet all clean air regulationsexcept possibly for nitrogen oxides, which are exacerbated by the traffic levels in the citycentre. Only virgin wood sources will be used for woodchip production and no waste orrecycled wood will be used; this avoids any possible contamination of the fuel supply andreduces the risk of harmful emissions.

B.9 Good service roads were already in place through residential areas as the site of the biomassfacility is within the existing community heating station, which is accustomed to takingdeliveries by oil tanker and was originally designed to cope with coal lorries. The newbiomass plant will require 2 lorries per day, 5 days per week; 4 days’ worth of fuel will bestored on site to cover operation over holiday periods. The 20 tonnes of ash produced perannum will be collected and distributed by the farmers who supply the woodchip, to beused for farm products such as fertiliser.


B.10 Concerns such as disruption from road works have been minimised by initiatives suchas ‘green digs’. A bridge needed to carry the hot water pipes over a major road, forexample, will also carry a cycle path, to add benefits for the community and to reducedisruption. Local media have been used extensively to engage the public and toidentify and address their concerns; this has been a major part of the project to raiseawareness of the benefits of a sustainable energy supply. This will be managedthroughout the project. Milestones will be set which clearly involve the media and thelocal community. In the Leicester Biomass scheme the use of CCTV during theinstallation of the biomass station and its future operation will allow the local schoolsto utilise the sustainability elements to fit within the national curriculum and to engagewith the project. This service would also be available through a website accessible toeveryone.

Case Study 2: West Dean district heating system

Background

B.11 The West Dean heating system was installed in 1983 to heat the main West Dean Collegebuilding, it was subsequently extended to include a number of extra buildings and is in theprocess of being further extended throughout the estate. Wood chippings from surplusmaterials that arise from the management of the estate’s 2,000 acres of forest are used togenerate the heat.

Forest management and fuel production

B.12 The primary function of the management of the estate’s forest is to produce timber andfirewood. The material that is chipped is the low quality wood that cannot be marketed andthe thinnings from the forest management. Prior to chipping, the wood is left at the forestedge for a year to dry to 30% moisture, therefore increasing fuel efficiency. During 2003,1,200 tonnes of chips were required to generate 1650MW(th).

B.13 The West Dean system is economically viable because many of the production costs aremet by normal forestry activities. Very few of the processes used in producing the fuel havebeen introduced specifically for this purpose.

B.14 The delivery of the wood to the chipper is combined with the return of equipment to nightstorage each evening and so requires no additional journeys (although transport fuel use isslightly higher for a loaded vehicle). Excess materials from the chipping process (bark, twigsetc) are returned to the forest floor when the machinery is driven to the forest each morning.The ash from the power plant is also returned to the forest floor; it is of little use as afertiliser but the estate sees this as an acceptable waste disposal route. The main additionalcosts involved in the provision of chips for the heating system are those from loading andunloading the wood and the chipping itself.


New build, retrofitting and expansion

B.15 The main initial investment for installing a district heating system, whether new build orretrofit, lies in the purchase of the equipment. This is made more costly by the lack ofdomestic suppliers of suitable machinery. At West Dean, with the exception of the waterheating pumps, all of the equipment was imported from Sweden and Denmark; thissubsequently increases repair and maintenance costs.

B.16 The West Dean system was entirely a retrofit project to replace an old oil powered system.The costs involved in exchanging one wet heat system for another were minimal. It wasmade easier by the fact that all of the buildings being refitted belonged to the estate. It wasanticipated that problems could arise in retrofitting properties in a market system, as thereis no guarantee that consumers will always opt to remain in the district heat system andinvestment may be lost.

B.17 The main expense in extending a district heating system lies in the underground piping.West Dean has recently purchased 150m of piping for their extension plans at a cost of £29k(this includes the engineering and installation costs). This cost would be expected to dropas demand increased but it is nonetheless a massive capital investment cost.

Prospects for expansion

B.18 The West Dean estate and Nottingham University recently conducted a joint investigationinto the possibility of utilising the waste heat from the production plant to operate a lowlevel steam turbine to generate electrical power. The project was considered too costlyunless significant grants were made available to establish West Dean as a demonstrationplant. The aim was to make the generation plant self-powering but the project did not goahead as the capital investment required was too high.

Case study 3: Enköping - use of sewage sludge113

B.19 To help meet a Helsinki agreement obligation to reduce nitrogen inputs to the Baltic Sea, theenergy company Ena Kraft, which is based in Enköping in Sweden, is using sewage sludge asa fertiliser for its willow plantations. This is cheaper than usual nitrogen removal processesand has proved so successful that the municipal council has financed additional willowplantations and is processing sewage from private septic plants as well as municipal waste.

B.20 By using sewage to irrigate willow, the Enköping council diverts 250-300 kg nitrogen/ha/yfrom surface waters and, ultimately, from the Baltic. Phosphorous and heavy metals aresimilarly removed. Bottom ash from the Ena Kraft CHP plant is also added into thisfertiliser mix.

B.21 By using sewage sludge and recycling the bottom ash, Ena Kraft not only meets its air qualityand CO2 targets by using willow as a fuel in its power station and also secures otherenvironmental benefits not normally associated with energy production. Ena Kraft attributesthe success of this project to the co-operation of a number of stakeholders including themunicipal water and wastewater works, the power plant, the environmental conservation

board, the municipal council and the farmers. It is a complex system and requires planning,discussion and effort to make it work, but once established it operates well.

Case study 4: Bristol and Avon - woodfuel for heat114

B.22 Bristol City Council and surrounding local authorities and agencies have been developingstrategies for increasing the role of wood fuel in their area. With substantial forestryresources and good opportunities for growing energy crops nearby, there is good potentialsynergy between political aspirations and biomass fuel resources.

B.23 The Bristol City Council Sustainable City Team commissioned a detailed feasibility studyinto the potential for using local biomass as a source of renewable energy for Council sites.The study identified a number of potential sites and also assessed the potential for biomasssupply within the city.

B.24 A 700 kW biomass boiler at a social housing scheme would save about 70% of the currentgas consumption, and reduce CO2 emissions by 266 tonnes per year. At a plant nursery,greenhouse heating currently consumes 56,000 litres of LPG and 15,000 litres of oil eachgrowing season. A 400kW biomass boiler could reduce this by 90% and save 68 tonnes ofCO2 emissions each year.


76 hawillowfield

120 hawillowfield

Salix uptakefrom ground:Cd: 9,8 g/ha & yearCu: 55Cr: 41Hg: 0,34Ni: 28 Pb: 9.86 Zn: 731 Cd: 0,75 g/ha & year

Cu: 194,5Cr: 26,1Hg: 0,33Ni: 12,9 Pb: 15 Zn: 324

Bottom ashCd: 10%Cu: 50%Cr: 60%Hg: 20%Ni: 30%Pb: 20%Zn: 20%

Fly ashCd: 90%Cu: 50%Cr: 40%Hg: 80%Ni: 70%Pb: 80%Zn: 80%

Cd: <1,1 g/ha & yearCu: 183Cr: <13Hg: <0,4Ni: 25 Pb: 13 Zn: 341

Total fuelinput: 350 GWh

ChipsSawdustWillowBark

100% Boiler Electrostaticprecipitator

Flue-gascondenser ch

imne

y

Deposit

Digested sludge

Clean water &sludge water

Waste watertreatment plant

Ash/sludgemix

irrigationproject

200,000m3/year

Condensed water30,000 m3/year

Clean water

3,8 milj. m3/year

River

Figure B-I Metal cycle in Enköping CHP-plant


B.25 Interest in utilising sawdust from a Council-run joinery has also led to an assessment of theopportunity for investing in a small-scale wood pelleting system. This could producearound 1,500 tonnes of good quality pellets a year for use in local biomass heating systems.

B.26 Two other potential sources of local biomass supply were identified. Existing resourcesfrom council woodlands, and other municipal arisings were available, as well as residuesfrom tree surgeons. In the latter case, the tree surgeons were keen to contribute as long as acentral site for disposal and drying was available. Avon Community Woodland is one of theseries of Community Woodlands developed across the country, it brings together localauthorities and agencies for specific actions and co-ordination of policy. A great deal of treeplanting has taken place in the Community Woodlands over the past decade, butcommercial outlets for both thinnings and more mature trees are reducing in line withoverall poor market conditions for timber. A series of actions is underway to stimulatemarkets for wood heating across the region in order to encourage additional markets forthis resource. Another source was recycled untreated wood waste such as wood chipproduced from pallets and off-cuts from timber processing (which a local wastemanagement contractor could supply). In total, around 960 oven-dried tonnes (odt) of fuelper annum was identified within the Bristol area.

Example costings

Case study 5: Biomass Heating Economic Evaluation115

500kW(th) boiler for a school and swimming pool

Biomass Heating - Base Case


HEAT ONLY

POOL Annual Heat Consumption 1,100,000 kWh

SCHOOL Annual Heat Consumption 1,250,000 kWh

Variables Price of Gas 1.50 p/kWh

Wood chip £30 £/tonne

Discount rate 6 %

Period 20 years

POOL

NPV

Cost of biomass system 1 £39,000 Total Net Saving £92,201

Cost of gas system £15,000

NPV of scheme £68,201

Cost differential £24,000

Cost per tonne of CO2 £16.32

Cost of heating with gas £16,500

Cost of heating with wood £8,462

Annual Savings on Fuel £8,038

CO2 savings per year 209 Tonnes CO2

POOL and SCHOOL

NPV

Cost of biomass system 2 £88,293 Total NPV Saving £196,973.84

Cost of gas system 3 £47,000

NPV of scheme £155,680.84

Cost differential £41,293

Cost per tonne of -£17.43 CO2

Cost of heating with gas £35,250

Cost of heating with wood £18,077

Annual Savings on Fuel £17,173

CO2 savings per year 447 Tonnes CO2

1 Net after c. 25% capital grant

2 Net after c. 25% capital grant3 includes heat mains


Case study 6: Biomass CHP Economic Evaluation116

260kW(e) and 500W(th) for a school and swimming pool

CHP- Base Case

CHP

Total electricity generated 1,260,000 kWh

Amount of wood consumed 1,077 Tonnes Assume 30% electrical efficiency

Discount rate 6%

Variables Price of Electricity 5.20 p/kWh

Annuity Factor 11.46992

Amount of CO2 saved 988 tonnes /year

SCHOOL and POOL

Capital Costs NPV

Capital cost of installation £320,000 Total Cost £342,000

Pipe work and linking to school £22,000

Total £342,000 NPV of income £568,476

Running Costs NPV of scheme £226,476

O/M £18,900

Cost of Wood Chip £32,308 Cost per tonne of CO2 -£11.46

Net Costs £51,208

Income

Income from electricity sales £65,520

Sales of heat £35,250

Total Income £100,770

Net Income £49,562

APPENDIX C - SCOPE AND LIMITATIONS OF THESPECIAL REPORT

C.1 Compared to other forms of renewable energy, energy from biomass attracts little attention.The number of projects using biomass energy in the UK is far less than that from energyfrom waste or wind power. The Commission analysed the various forms of renewableenergy in its Twenty-second Report ‘Energy - The Changing Climate’. This study wascommissioned to investigate developments in biomass energy since the Twenty-secondReport, exploring the introduction of new technology and the extent to which governmentenergy policy has provided appropriate incentives for its introduction.

C.2 The main focus of this report has been on biomass as a source of heat and power particularlythrough the use of CHP (combined heat and power) plants. Unlike most other sources ofrenewable energy, biomass has the advantage that it can be stored, and therefore controlled;it is also the source of a considerable amount of heat that, if captured and utilised, can offerhigh efficiencies and significant CO2 savings.

C.3 A study of biomass was considered timely because of the recent failure of the ARBREproject. Other countries have major programmes using biomass as a source of renewableenergy, both for heat and power, and are developing technologies and infrastructure toenable them to do this, yet the recent Energy White Paper had few proposals in this area.The UK is in danger of being left behind, and the collapse of ARBRE may exacerbate this.If the government is to achieve its stated aims for the reduction of greenhouse gases and UKindustry is to keep abreast of developments in this area, the use of biomass will need furthergovernment support. This study explored the importance of such support and possibleforms that it might take.

C.4 Concerns about the environmental consequences of growing energy crops and emissionsfrom biomass energy plants have been addressed and the carbon lifecycle examined, as wellas the energy balance involved in long-distance transportation of biomass for fuel. Publicconcerns about the large-scale cultivation and use of energy crops, fears about impacts ontraditional farming, the landscape and air quality, have been explored and ways ofincorporating them into renewable energy policies have been suggested.

C.5 This study has addressed the wider implications for biomass schemes; for example,biomass-fuelled plant can also play a role in waste management. CHP plants can co-firebiomass with coal, and some agricultural wastes can be used as fuel.

C.6 The issue of waste was raised a number of times during the course of this study, particularlywith regards to sewage disposal and diverting virgin wood from landfill. These options havebeen explored as components of the biomass energy process, but we have not coveredenergy from waste in general. We have already addressed this issue in our SeventeenthReport.



C.7 This report was restricted to an overview of the potential for biomass energy production andaimed to highlight the variety of options available that could be tailored to individualsituations. We have not taken a prescriptive approach and have not attempted to determinefuel availability and technology suitability for specific areas of the UK; although we havemade recommendations that such analyses be carried out on a regional basis.

C.8 This report does not cover biofuels for transport or energy carriers such as hydrogenproduced from hydrocarbons. Fuels such as bioethanol from cereals and biodiesel from oilseeds may have a role as fuels for surface transport but applications of woody biomass toproduce transport fuels are more speculative. Woody biomass gives a higher energy yieldper hectare than transport fuels from cereals or oil seed crops. It was therefore decided torestrict the coverage of the report to the higher energy yield option of biomass. Biofuels arenot covered in this report as we view them as longer-term possibilities that might beappropriate if surplus biomass or land is available once the more immediate applications forwoody biomass have been exploited.

C.9 Many fuels and technologies for energy generation can make contributions to reducingemissions of CO2 and other greenhouse gases. We acknowledged the need for a diverseenergy portfolio in our Twenty-second Report and we urge the government to place anemphasis on alternative energy sources and to develop policy and support mechanisms toencourage the renewables sector. We consider biomass to be a vital, viable part of thisgeneration mix that offers real opportunities for UK energy, environment and agriculture.


APPENDIX D - CONDUCT OF THE REPORT

D.1 The Commission announced the special report in August 2003 and called for evidencefrom a wide range of organisations and individuals. The questions focused on: the principalenvironmental benefits and disbenefits of biomass as a source of heat and power energy;the public concerns regarding biomass energy generation, why these concerns arise andhow they can be taken account of in the future development of biomass energy generation;the level of investment needed in order to introduce effective co-firing of biomass and fossilfuels; the extent to which fossil fuels could be replaced by biomass, the timescale necessaryto develop a large-scale switch from fossil to bioenergy and the medium-term measuresneeded to bring this about; the impacts on agriculture and the support available forchanging land use to energy crops; the proportion of biomass that could be provided byforestry and agricultural by-products.

D.2 The initial invitation included questions on the viability of transport fuels from cereal andoil-seed production. It was subsequently decided that this would require a report in its ownright and that it would not be covered in the course of this study.

D.3 This invitation was also placed on the Commission’s website with an invitation to respond.Overall 30 organisations responded to the invitation. The report was drafted betweenJanuary and April 2004.

D.4 The organisations and individuals who responded to our invitation to submit evidence orprovided information on request or otherwise gave assistance are listed below. In somecases, indicated by an asterisk* meetings were held with Commission Members orSecretariat so that particular issues could be discussed.

Government Departments

Department for Environment, Food and Rural Affairs*

Department for Trade and Industry*

Scottish Executive Environment and Rural Affairs Department*

Other organisations

Association of Electricity Producers

Agrobransle AB, Sweden*

Bio-renewables Ltd

British Association for Biofuels and Oil

British Biogen*

British Energy

The Carbon Trust

Combined Heat and Power Association*

Confederation of UK Coal Producers


Council for Nature Conservation and the Countryside

Countryside Council for Wales

Ena Kraft AB, Sweden*

Energy Advisory Associates

Energy Savings Trust

Engineering and Physical Sciences Research Council

English Nature

Environment Agency

EPRI

European Environment Agency

Federation of Swedish Farmers*

Forest Research*

Forestry Commission*

Leicester City Council*

MRETT

National Farmers’ Union*

National Society for Clean Air

Natural Environment Research Council

Nottinghamshire County Council

Ofgem*

Ofreg

Power Generation Contractors

Regen SW*

Renewable Power Association

Royal Society of Edinburgh

RWE Innogy*

Scottish Natural Heritage

Scottish Power

SEPA

Shell

Swedish Energy Agency*

Termiska Processer AB (TPS), Sweden*

Ulster Farmers’ Union

UNEP

United Utilities Plc

Individuals

Mr Syed Ahmed, CHPA*

Mrs Lena Åsheim, Lillöhus AB, Sweden*


Dr Ausilio Bauen, Centre for Energy Policy and Technology, Imperial College

Mr Peter Billins, British Biogen*

Mr Stewart Boyle, Wood Energy Ltd

Professor AV Bridgwater, Bioenergy Research Group, Aston University

Dr R V Birnie, Macauley Land Use Research Institute*

Mr Rupert Burr, Roves Farm*

Sir Ben Gill, National Farmers Union*

Mr Eric Herland, Federation of Swedish Farmers*

Mr Eddie Johansson, Ena Kraft AB, Sweden*

Professor Tomas Kåberger, International Institute for Industrial Environmental Economics,

Lund University

Mr Don Lack, Leicester Energy Agency, Leicester City Council*

Dr Stig Larsson, Agrobransle AB*

Mr Anders Lewald, Swedish Energy Agency*

Mr Henrik Lundberg, Termiska Processer AB (TPS), Sweden*

Mr Peter McDonald, Fyne Homes*

Dr Helen McKay, Forestry Commission*

Mr Graham Meeks, CHPA*

Mr Gustav Melin, Agrobransle AB, Sweden*

Mr Kent Nystrom, Svebio and Aebiom, Sweden*

Erik Rensfelt, Termiska Processer AB (TPS), Sweden*

Mr Mathew Spencer, Regen SW*

Mr Ian Tubby, Forest Research*

Mr Lars Waldheim, Termiska Processer AB (TPS), Sweden*

Commissioned Studies

The following papers were commissioned in the course of the study:

An analysis of the use of biomass for energy. A. Bauen, R. Dixon, J. Howes (E4 tech (UK) Ltd),J. Woods, Centre for Energy Policy and Technology, Imperial College London. 2004.

An analysis of the Combined Heat and Power Quality Assurance Scheme. S. Boyle, Wood Energy LtdMarch 2004.

Economics of biomass heating and power systems. S. Boyle, Wood Energy Ltd. March 2004.

Land requirements of bio-power and CHP plant. S. Boyle, Wood Energy Ltd. March 2004.

A summary of progress made on the four scenarios since the publication of the Twenty-second Report.S. Boyle, Wood Energy Ltd. March 2004.


APPENDIX E – MEMBERS OF THE COMMISSION

Sir Tom Blundell (Chair) Sir William Dunn Professor and Head of Department of Biochemistry, University of Cambridge andProfessorial Fellow, Sidney Sussex College

Professor Roland Clift Distinguished Professor of Environmental Technology and Director, Centre for EnvironmentalStrategy, University of Surrey

Professor Paul Ekins Head, Environment Group, Policy Studies Institute

Sir Brian Follett Chair, Teacher Training AgencyChair, Arts and Humanities Research Board

Dr Ian Graham-Bryce President, Scottish Association for Marine Science

Professor Stephen Holgate Medical Research Council Clinical Professor of Immunopharmacology, University of Southampton

Professor Brian Hoskins Royal Society Research Professor and Professor of Meteorology, University of Reading

Professor Jeffrey Jowell QCProfessor of Public Law, University College London

Dr Susan Owens Reader in Environment and Policy, University of Cambridge, Department of Geography, and Fellowof Newnham College

Professor Jane Plant Chief Scientist, British Geological Survey (Natural Environment Research Council)

Professor Steve Rayner James Martin Professor of Science and Civilization, Saïd Business School, Oxford University

Mr John Speirs Chairman, Chemistry Leadership Council’s Futures Group

Professor Janet Sprent Emeritus Professor of Plant Biology, University of DundeeBoard Member, Scottish Natural Heritage

Secretariat

SecretaryTom Eddy(Mr Eddy took over from Dr Peter Hinchcliffe who retired end of March 2004)

Assistant SecretariesGeorgina BurneyDiana Wilkins

Policy AnalystsRhian EnrightAndy DeaconJonny Wentworth

Information ManagerGuy Mawhinney

Office ManagerRosemary Ferguson

Administrative OfficersBaaba DavisGeoff Ofodile

Personal Secretary to the Chairman and Mr EddyDot Watson

APPENDIX F – REPORTS BY THE ROYAL COMMISSIONON ENVIRONMENTAL POLLUTION

24th report Chemicals in Products – Safeguarding the Environment Cm 5827, June 2003and Human Health

Special report The Environmental Effects of Civil Aircraft in Flight

23rd report Environmental Planning Cm 5459, March 2002

22nd report Energy – the Changing Climate Cm 4749, June 2000

21st report Setting Environmental Standards Cm 4053, October 1998

20th report Transport and the Environment Cm 3752, September 1997–Developments since 1994

19th report Sustainable Use of Soil Cm 3165, February 1996

18th report Transport and the Environment Cm 2674, October 1994

17th report Incineration of Waste Cm 2181, May 1993

16th report Freshwater Quality Cm 1966, June 1992

15th report Emissions from Heavy Duty Diesel Vehicles Cm 1631, September 1991

14th report GENHAZ Cm 1557, June 1991A system for the critical appraisal of proposalsto release genetically modified organisms intothe environment

13th report The Release of Genetically Engineered Cm 720, July 1989Organisms to the Environment

12th report Best Practicable Environmental Option Cm 310, February 1988

11th report Managing Waste: The Duty of Care Cmnd 9675, December 1985

10th report Tackling Pollution – Experience and Prospects Cmnd 9149, February 1984

9th report Lead in the Environment Cmnd 8852, April 1983

8th report Oil Pollution of the Sea Cmnd 8358, October 1981

7th report Agriculture and Pollution Cmnd 7644, September 1979

6th report Nuclear Power and the Environment Cmnd 6618, September 1976

5th report Air Pollution Control: An Integrated Approach Cmnd 6371, January 1976

4th report Pollution Control: Progress and Problems Cmnd 5780, December 1974

3rd report Pollution in Some British Estuaries and Coastal Cmnd 5054, September 1972Waters

2nd report Three Issues in Industrial Pollution Cmnd 4894, March 1972

First Report Cmnd 4585, February 1971



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Image titles and credits

Front cover Poplar & willow fuelwood plantation in Avon, copyright 1997 – 2002Science Photo Library.

Bales of straw, copyright 1997 – 2002 Science Photo Library.

View of coppiced woodland in Norfolk, England, copyright 1997 – 2002Science Photo Library.

Forest worker uses chainsaw to clear storm damage, copyright 1997 – 2002Science Photo Library.

Tractor harvesting coppiced willow, Forest Research (2004).

Chipper and storage shed, West Dean P. R. Hinchcliffe (2003).

Page 11 Coppiced poplar wood chips in farmer’s hands, copyright 1997 – 2002Science Photo Library.

Page 26 Forestry workers feed cut branches into shredder, copyright 1997 – 2002Science Photo Library.

Page 32 Chipper and storage shed, P. R. Hinchcliffe (2003).

Page 65 Wood chipper and storage shed surrounded by walls and trees, West DeanP. R. Hinchcliffe (2003).

The Royal Commission on Environmental Pollution is an independent body,

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in-depth reports on what it identifies as the crucial environmental issues

facing the UK and the world.

Information on the Commission’s work can be found at www.rcep.org.uk.

Copies of this report are available to download from the website,

alternatively, the Commission can be contacted at:

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ROYAL COMMISSION ON Biomass as a Renewable Energy Source · ROYAL COMMISSION ONENVIRONMENTALPOLLUTION – BIOMASS AS A RENEWABLE ENERGY SOURCE 5 means that most of our fuels will