CHAPTER

INTRODUCTIONAND

RATIONALEFORTHE

STUDIES

1

Introduction

This project was implemented with funding from the Netherlands Government as part of the Neth-erlands Climate Change Studies Assistance Programme (NCCSAP). The project included capacitybuilding in the sense that local consultants carried out most of the work with support from Ministryof Environment and Tourism and Southern Centre for Energy and Environment.

The local experts that carried out the study received technical assistance from the Institute for Envi-ronmental Studies and international consultants in the form of scheduled backstopping visits as wellas through fax and email.This energy sector study was anchored on factory surveys and consultation with policy makers. Thefactory visits included technical audits with the consultants aiming to identify opportunities for en-ergy efficiency improvement and emission reduction whilst at the same time listing the barriers tosuch initiatives and analysing opportunities to overcome these barriers. The findings of the consult-ants were discussed in stakeholder workshops and the bulk of this report is based on those findings.

This report includes four chapters where chapter 1 gives the project background and rationale aswell as a background to the energy sector in Zimbabwe. Chapter 2 gives a general description of theselected case studies most of which are in private companies. Chapter 3 explains the mitigation op-tions in more detail and also discusses the main activities of the host companies. Chapter 4 analysesthe options and present the cost and benefits of the options including recommendations on possiblenext steps.

Background Information

Zimbabwe’s economy is largely agro-based. Agriculture contributes about 16% of GDP. This sectoris followed by mining in order of economic importance. However, agriculture remains by far themost important sector of the economy since it supports over 80% of the population with the rest ofthe population being linked to this sector through manufacturing, i.e. agriculture provides the bulkof the raw materials required in manufacturing. Manufacturing contributes about 25% of the GDPand employs 17% of the total employed labour force.

Zimbabwe consumes about 280 PJ of energy annually (1992 data) with 44.6% of this coming fromcoal, 12.4% is derived from petroleum and 4.5% is generated from hydroelectric power. Biomass,which provides 93% of energy for rural households, contributes about 39.4% to the total energy sup-ply base annually.

From the foregoing, it is clear that the country’s energy consumption pattern is carbon intensive.Under this scenario, the need for mitigation options buttressed by the formulation of a national andinstitutional framework for a concerted mitigatory effort is imperative.

In order to come with viable mitigation options in the energy sector, a discussion of Zimbabwe’senergy base is imperative. The country has considerable coal deposits with proven reserves lasting107 years at the present annual depletion rate of 4.7 million tones. The second mine at Sengwa has anannual production capacity of 200 000 tonnes. In 1992, 2 - 4 million tonnes of coal (usually raw coal)were consumed by thermal power generation.

In addition to coal, Zimbabwe has discovered reserves of coal-bed methane, which is being consid-ered for exploitation mainly for power generation and industrial gas. Output from the deposits isestimated at 2 - 3 million m3 a month.

Energy Base

Fuel woodWood provides over 95% to 90% of the country’s households being the basic fuel for low incomeurban households who consume an average of 5kg a day in unelectrified houses, 1-2k in housessupplied with load limited electricity and 1.7kg in households with metered or unlimited electricitysupply. Total fuel wood consumption is estimated at 6 million tonnes annually. Mitigation efforts inthis sector cannot be haphazard because of the social sensitivity of the present beneficiaries of energyfrom wood.

Liquid FuelsPetroleum products are imported as finished products within the liquid fuel base, diesel is the keyfuel - the productive sector consumes about 71% in heavy haulage and railway traction, 8% in min-ing operations, 15% in agriculture and smaller amounts in other operations including plant start upsand flame stabilizations in industrial and power utility boilers.

Electricity - Internal SourcesZimbabwe has an internal installed electricity generation capacity of 1,846MW. About 36% of this isfrom hydropower and 64% is from coal-based thermal plants.

a) Hydro electricity: The Zambezi River offers the most significant hydroelectric capacity. The riverhas a total capacity of 7,298MW on full stretch. 3,266MW of this have been exploited, 666MW onKariba South Bank operated by Zimbabwe, 600MW on Kariba North Bank operated by Zambiaand 2,000MW at Kabora Bassa further downstream in Mozambique. There are plans to furtherdevelop hydropower on the river including units with a total of 300MW at Kariba South Extension.It goes without saying that the investment decisions on these schemes depend on the relativecost and reliability of coal thermal options as well as the relative cost and reliability of imports.

b) Electricity - Regional Schemes: Electricity imports have become increasingly important as asource of electrical energy due to the efforts being made through the power interconnection inSouthern African Development Community and the recently formed SAAP - a protocol whichallows for further and more systematized trade in electricity across national borders. Zimbabweimports up to 300MW from Zambia, 25MW from Mozambique and has an infra structure toimport 500MW from South Africa. Imports from Zambia and Mozambique are fully decarbonizedwhile those from South Africa will be mainly from coal thermal sources. A key element of theregional power grid, which is embodied both in the interconnections and power pool, is the Ingaproject in the Democratic Republic of Congo (DRC), which has a massive hydropower capacitycapable of supplying 45MW to the region on full investment.

In this regard, Zimbabwe being a signatory of the UNFCCC has launched a far-reaching study throughthe Ministry of Mines and Energy to assess greenhouse gas mitigation potential of regional powerpooling.

Solar EnergySolar energy poses as the most promising option of renewable energy for the rural sector, particularlysmall appliances and provision of hot water to households and institutions. The local manufacturingindustry enjoys low import duties on solar related devices, which the government introduced as anincentive to encourage solar rural electrification, but even then, the prices are still unaffordable to themost people in Zimbabwe. Zimbabwe also boasts a well developed solar technological advance-ment based on the US$7 million GEF solar PV dissemination support pilot project.

Zimbabwe in conformity with its obligations of UNFCCC Convention submitted its Initial NationalCommunication to the UNFCCC Secretariat in May 1998. Zimbabwe’s priorities in as far as they rateto climate change are listed in the Initial National Communication as follows:

• Enhancement of capacity in research institutions, particularly research on vulnerability andadaptation technologies

• Training capacity building for climate change decision making in industry

• Enhancement of policy analysis (energy pricing, incentives, standards, regulations, etc)

• Studies on energy efficiency improvement in small-scale industries and in the formal sector(technology assessments) and alternative energy initiatives such as improved wood stoves,biomass stoves and coal stoves and biogas. Included among the priorities for projects are a numberof mitigation activities in the energy sector.

Earlier Climate Change Studies

Since the Rio Earth Summit, Zimbabwe has been involved in a number of climate change studies vizUnited States Country Studies Programme - USCSP (GHG inventories, mitigation and vulnerabilityand adaptation), UNDP Capacity Building Project in Sub-Saharan Africa Project, several mitigationstudies sponsored by RISO, the Initial National Communication under a GEF sponsorship throughUNEP and a World Bank sponsored National Strategy Study (NSS).

The UNEP GHG Abatement Costing Studies.This project was centred on developing methodologies for greenhouse gas abatement costing. In theabsence of emission inventories the project included a brief assessment of emissions from the energysector. The local partners in the project were Southern centre and the principal partner was the UNEPCollaborating Centre on Energy and Environment based at RISO in Denmark. In developing themethodologies the project also identified greenhouse gas mitigation options in the energy sector.

The US Country Studies Program.The US Country Studies Program was implemented when the methodologies for carrying out emis-sion inventories and abatement costing were more developed. The project therefore improved on thework done under the UNEP studies and developed a more comprehensive inventory of emissions. Inaddition the project assessed vulnerability of various sectors in Zimbabwe to climate change as wellas identifying a few adaptation options.

World Bank National Strategy StudyThe World Bank NSS was a study to help in drafting a framework for implementation of CDM projects.The study adopted mitigation options from previous works and updated them. The study then broughtkey stakeholders together to discuss a possible institutional framework for CDM. This was early inthe development of the CDM process hence the recommendations were preliminary.

UNDP Capacity Building Project in Sub-Saharan AfricaThe UNDP project was under the enabling activities program. The main objective was to build thecapacity of local institutions and individuals for the purpose of developing the National Communi-cation for the UNFCCC. Project teams were built and the information for the chapters of the firstNational Communication was collected under this study. This information was then fed into theUNEP supported activity to draft the first National Communication for Zimbabwe.

UNIDO CDM Capacity Building for AfricaThe main objective of this project was to build capacity in African countries to identify and developCDM projects. The project focus was on defining the role of institutions that would be involved indeveloping CDM projects. The project process included identification of some potential CDM projectsand barriers to their implementation. The barrier identification process was based on workshopswhere participants screened and predefined list of barriers. The list had been defined through asurvey of institutions that were either linked to project development or were involved in developingprojects. Unlike this study the UNIDO study did not carry out factory audits. The local partners toUNIDO were Southern Centre for energy and Environment.

Zimbabwe has had a significant number of studies carried out to determine technology improve-ment opportunities. The studies have been in the areas of climate change inventory of emissions andmitigation assessment, energy efficiency improvement, the administration of United Nations Frame-work Convention on Climate Change (UNFCCC) renewable energy technologies and applications,investment opportunities in clean technologies and the introduction of clean technologies in the plan-ning process. The studies have been extended to the regional level where SADC has investigated theregional potential for technology improvement.

The following table shows a list of some of the technology options that have been identified throughthe various studies mentioned above.

The technologies were studied mostly at the analytical level even though a lot of practical work hasbeen with renewable energy devices as well as industrial audits. Attempts to establish commercialenterprises trading in clean technologies have not yielded the volume of business that matches theresults of the market assessments.

Table 1.1 List of Options

Technology Description of Option

Domestic lighting High efficiency lamps

Electric water heaters Solar water heaters, usage regulation

Electric motors High efficiency motors, speed control, Power factor control.

Industrial boilers Steam use coordination, insulation improvement, flue gas heat recovery

Industrial furnaces Plasma arc furnaces

Foundries Waste heat steam boilers

Diesel tractors Low tillage agriculture

Road transport Ethanol-Gasoline blending

Low Carbon Fuel Coaled methane

Renewable Energy Wood waste power generation

Solar water heaters

PV Power

Crop waste gasification

Wind farm for electricity

Wind pumps

Solar cookers

Solar crop dryers

Solar refrigeration

Soft technology Industrial audits

Integrated resource planning

Rural electrification master-plan

Power Pool Analysis

Source: UNEP Abatement Costing Studies

Climate change studies touch on activities in various sectors. The nature of the UNFCCC and thethrust of current debate are such that greenhouse gas mitigation by developing countries is second-ary to development issues. The clean technology options identified for Zimbabwe therefore have adevelopment basis for consideration. In most cases the technologies were identified as a result ofstudies to do with energy efficiency improvement as a supply option, alternative agriculture prac-tices to reduce soil loss, coal conversion to liquid fuels or fertilizer as a way of reducing the importa-tion bill and reduction of the import bill for petroleum fuels by blending with ethanol.

Most of the technologies considered for climate change mitigation had not been implemented fordevelopment purposes as they had barriers to their implementation. The major barrier was financeeven though other secondary barriers could be identified in the assessments. Given the potential forclimate change funding the technologies were presented for assessment as climate change mitigationoptions. The natural coincidence of GHG reduction technologies and priorities for national develop-ment makes Zimbabwe a strong candidate for climate change mitigation. Policies can be implementedto address both local issues and global issues without compromise to development. The followingtable shows some of the technological concerns that are of importance to local development.

Table 1.2 Technological Options with local developmental Interest

Sector Technology Local benefitEnergy Solar Energy Low cost electrification,

Wind Energy Rural energy supplyHydroelectricity Rural electrificationEthanol gasoline blend Reduction of Energy Import BILLCoal liquification to fuel

Manufacturing Coal distillation to ammonia Reduce energy use in fertilizerAmmonia from coal bed methane production

Source: Department of Energy Files

Introduction of new technology requires a market assessment for opportune applications, an assess-ment of cost and benefits of applying the technology and an exercise to remove any major barriersthat would impede the diffusion of the technology. In most climate change studies the analysis endswith an assessment of the economic cost and benefit wit minimal evaluation of the qualitative barri-ers to implementation on the technology. The following table shows the results of the mitigationoptions studied by UNEP (1992).

Table 1:3 Cost Analysis for Selected Technology Options

Reduction option Cost Unit Unit Energy Emission

(Z$/tonCO2) Size Type Type reduction

Saved (tonCO2

equivalent/

unit)

1 New ethanol plant -5933.3 1 plant gasoline 47029.0

2 Tillage -3929.4 1 tractors diesel 18.5

3 Efficient lighting -4223.2 1000 Bulbs el-coal 54.1

4 Geyser time switches -309.1 units el-coal 1.3

5 Coal bed ammonia -662.4 83 MW coal 808131.3

6 Methane from sewage -542.2 1 plant el-coal 1203.8

7 Cokeoven gas for Hwankie -2987.6 15000000 l diesel eqv diesel 43941.9

8 Prepayment meters -409.3 200 units el-coal 1.9

9 Efficient motors -459.3 1000 KW el-coal 4.3

10 Efficient boilers -23.0 100 tonnes coal 1051.4

11 Savings in industry -14.0 in-split

12 Efficient tobacco barns 0.1 1 barn coal 639.7

13 Pine afforestation 9.9 1 ha wood 29.4

14 Biogas from landfills 0.0 1 Landfill el-coal 16425.0

15 Efficient furnaces -1407.1 2 MW coal 7241.7

16 Biogas for rural households 48.0 1 digesters wood 9.1

17 Hydro power 388.7 1 KW coal 8.2

18 Solar geysers -519.7 units el-coal 2.9

19 Central PV electricity 2702.4 1 kW coal 2.1

20 Power factor correction 31075.8 1 MVAR el-coal 778.5

From the foregoing, it is clear that so far there are some gaps in our climate change studies. Thesegaps can be categorized into:

i) Assessment of promising technologies for climate change mitigation and local energyefficiency improvement.

ii) Identification of barriers for adoption of recommended technologies (mitigation options by industry in Zimbabwe)

iii) An assessment of opportunities to overcome the identified barriers and opportunitiesfor implementation of projects under the Clean Development Mechanism.

These gaps are analysed in this study for a selected number of case studies

Current Study

The rationale of this study on identification of barriers is premised on the fact that a lot of climatechange studies have been conducted in Zimbabwe on the use of win-win mitigation technologies inindustry, but contrary to expectations, industry as a whole has not incorporated these proven moreefficient technologies into their operations.

In this study we intend to carry out a comparative analysis of the existing technologies currentlybeing used in Zimbabwe industries versus new win-win technologies, which are not in use in Zimba-bwe. The comparison will be based on energy consumption, costs (equipment procurement andoperational), life span of equipment as well as long and short-term economic and environmentalbenefits. From such an analysis, it is hoped to identify the barriers for adoption of the new win-wintechnologies by Zimbabwean industries. In a further analysis, we will also consider remedies tothese barriers and explore ways of how Zimbabwe can fully participate in Clean Development Mecha-nism (CDM) projects.

Some of the generic possible barriers for industry could include patents and licensing restrictions,insufficiency of available capital and hard currency, dearth of information on long-term economicand environmental benefits associated with switching to energy-saving technologies, insufficientincentives, etc. We, therefore, expect that a detailed study of individual industries, case by case,should reveal the exact nature of these barriers.

Although climate change studies hitherto conducted in Zimbabwe deal with and assess a number ofsuch technologies, they fall short of being direct value in an economic or business sense to industries.They are written from the perspective of an outsider researcher with hardly any consultations withthe financial or production managers of concerned industrial firms, i.e. they are technology-drivenrather than demand driven.

With this in view, the aim of the proposed research is to highlight the positive aspects of the recom-mended technological mitigation options that have been studied in Zimbabwe such that industrywill see merit in implementing them.

METHODOLOGYANDCASE

STUDIES

CHAPTER

2

Methodology

General Methodology for Technology AssessmentThere are five basic steps to mitigation analysis. These steps were followed in the earlier UNEPCollaborating Centre studies mentioned in Chapter 1. The steps are as follows:

• Evaluation of national and social Development, and

• Comprehensive evaluation of national social and economic development framework forclimate change mitigation.

These steps include:

Baseline scenario projection.The baseline saves to show the sequence of events and activities if climate change mitigation wasnot a criterion for development. The time span of the baseline depends on the technology beingassessed. The idea is to ass the technology as close to the lifecycle as possible.

Mitigation Scenario ProjectionIdentification and assessment of emission reduction options for the major future sources ofemissions.

Macroeconomic AssessmentAssessment of key macroeconomic parameters and qualitative description of macroeconomicimpacts.

Implementation IssuesIdentification of policy, finance, institutional and technology needs for implementation.

The data requirements in mitigation analysis can be extensive. Figure 4.2 shows some of the datarequirements as used in running LEAP, a mitigation analysis model. The technical data would thenbe used in combination with socioeconomic and political information to develop a strategy for im-plementation of the technology.

WorkshopsIn addition to research into the adoption of win-win mitigation options as well as vulnerability andadaptation in agriculture, we held three major workshops to discuss project implementation andresults. We involved all possible stakeholders in all the three workshops. It was prudent to involveall stakeholders right from the outset so as to avoid possible coordination problems. Details of theworkshops are presented in Annexure I.

Figure 4.4: Example Data Requirements for Mitigation Analysis.

Example: Data requirements for GHG Emissions Estimation at each Node

Engineering Performance Data Economic Data Enviromnmental Data Other Data-Energy output -Cost -Emission rates • Type • Capital • Air pollutants • Range • Operating • Water Pollutant- Enegy Inputs -Finacial • Solid Waste • Input Fuel -Interest Rates generation • Input material • Tax Structure - Control alternatives • Restrictions • Revenue fomulars • Equipment- Themodynamic efficiency • Foreign exchange • Operational • Current Future • Escalating rates charges -Perfomance limits - Control costs • Design, maximum, minimum • O perational– Construction Requirements • Lead Time • Construction period • Lifetime- Technology Status • Commecial, pilot, research General Subsector

Source: LEAP Manual, SEI Boston.

In this project the technology data was collected from previous feasibility studies as well asthrough factory visits. Where data was not readily available some generic data from engineeringmanuals and the internet was adopted. Calculations were then made in Chapter 4 on the basis ofthis data.

Selection of and introduction to selected case studies

Selection of case studiesThe main criteria for selecting these firms were the existence of alternative technologies. This criteriais important so as to get the basis for comparison. Other criteria included abatement technologies,prices, life span if equipment, energy consumption, etc. The next section covers a synopsis of thecompanies that were involved in the study.

The following section provides an introduction to the selected case studies.

Introduction to the selected case studies

Zimbabwe Electricity Supply Authority (ZESA)

Current Electricity Production

In Zimbabwe, ZESA has the mandate to ensure that there is adequate electrical energy to meet thenation’s requirements. The authority is, therefore, tasked with providing safe, reliable and secure

electricity supply service to the nation at competitive prices. The Authority is operating two majorstations, Hwange thermal power station with an installed capacity of 920MW and Kariba Southhydropower station with an installed capacity of 666MW. It also runs old thermal power plants atMunyati (120MW), Harare (135MW) and Bulawayo (120MW). The electrical energy is transported tothe bulk supply points through a meshed network consisting of a total of 3,500km of 330Kv transmis-sion lines. Energy is delivered to the various load centers through a sub transmission network con-sisting of 1,280km of 132Kv lines, 2,150km of 188Kv lines and 180km of 66Kv lines. The distributionnetwork is made up of 33Kv, 22Kv and 11Kv lines. A long historical background of the electricitysector development has led to the present blend of voltage standards.

The ZESA energy and power supply situation for 1999 is given in Table 2.1 below:

Table 2.1

Source Installed Capacity Generation (MWh) Energy Sent Out(MW)

Kariba Hydro P/Stn 666 2,957.174 2,949.316Hwange Power Stn 920 4,210.458 3,866.002Munyati Power Stn 120 130.645 121.113Harare Power Stn 135 120.155 110.049Bulawayo Power Stn 120 47.202 44.290Sub-total 1,961 7465.634 7,090.770Imports 700 5,274.390

Considerable results from RISO show that 2010 GWh could be saved as a result of activities shown inTable 2.3.

Table 2.3: Potential for electricity savings from DSM

Item Total Energy Opportunity/ payback/

Savings (MWhrs/yr) constraints

(%)

Waste and loss reduction 8.5 170,000 VG/High/V-None

New generation of fluorescent lamps 7.5 150,000

High pressure sodium lamps 1.5 30,000 VG/High/V

Improved use of electric motors 1.0 20,000 VG/High/V

Metering 0.7 15,000 VG/High/V

Substitution of 100W and 60W incandescent 0.7 15,000 VG/High/V

More efficient motors 3.7 75,000 G/Medium/few

Improvement in Electro-thermal processes 4.2 85,000 G/Medium/few

Power factor improvement 0.5 10,000 G/Medium/few

Adjustable speed drives 1.7 35,000 Low/low/V-None

Substitution of electrolysis 39.9 800,000 Low/low/V-None

Solar water heaters for domestic use 15.9 320,000 Low/Good/some

Compact fluorescent lamps 5.2 105,000 Low/Good/some

Substitution of electricity for cooking 5.0 100,000 Low/Good/some

Improved fridges 2.0 40,000 Low/Good/some

Substitution of electricity for commercial

water heating 2.0 40,000 Low/Good/some

Total 100 2,010,000

Source: ZESA System Load Forecast, April 2000

Time SwitchesElectric geysers consume about 40% of total household electricity in high-income suburbs. Electric-ity accounts for 13.8% of household energy consumption. In rural areas 98.2% of the householdenergy demand is covered by wood. There are over 100 000 domestic electric geysers in the country.The majority of these have poor insulation and result in massive heat loss forcing the thermostat totrigger reheating throughout the day when hot water is not being used. To reduce losses, a timeswitch could be connected to the geyser circuit. This would typically allow water heating whenrequired and switch off the geyser when hot water is not needed. Careful setting of the timer willreduce losses significantly allowing for short (2 years) payback periods. The investment per unit isabout U$11.

Solar Water HeatersSolar water heaters can displace about 80% of the electricity used for water heating in individualhouseholds. The solar water heater would typically be fitted with a standby electrical element for useduring periods of cloud cover or at night. Some households favor the use of solar water heaterswithout electrical elements. The heaters cost about USD1000=00 for 100 liter units. The price of solarwater heaters is such that only high-income households can afford them. Some units are made forlow-income users but most of these are not cheap enough for these intended households.

Sable ChemicalsSable Chemical Industries is a private limited company situated in the Midlands province of Zimba-bwe, 203km from Harare and 17km before Kwekwe along the Harare-Bulawayo road. Its core busi-ness is the manufacture of Ammonia Nitrate (NH4NO3) fertilizer, an essential input for the Agro-Industrial sector in Zimbabwe. Excess oxygen, produced as an intermediate product is sold to theZimbabwe Iron and Steel Company (ZISCO) and other consumers for industrial and commercialapplications.

The inclusion of Sable Chemicals in the project study was based on the fact that with an installeddemand of 115MW, and an average annual energy consumption of 905,663 MWh for 1999; it is thelargest single consumer of electricity and also the largest single electricity sales revenue source forZESA.

Its demand, the bulk of which goes into the electrolytic breakdown of water into hydrogen and oxy-gen, represents about 7% of the national demand. It is assumed that, with everything else remainingconstant, a reduction in its demand will result in significant Greenhouse Gas (GHG) emission reduc-tion at source.

Zimbabwe Mining and Smelting Company (ZIMASCO) Pvt. Ltd. / ZimbabweAlloys (ZIMALLOYS) Limited - Energy EfficientBoth companies are located in the Midlands province of Zimbabwe with their head offices in Harare.Their core-business is the production of high carbon ferro-chrome for export overseas mainly Europeand Japan. Their operations cover the mining and transportation of chrome ores blending them withcoke and fluxes and smelting the blend in electric submerged arc furnaces to separate ferro-chromemetal from additives. The smelting part of these processes is by far the most significant energy-consuming stage and any improvement that can be made to improve efficiency of this process step isbound to result in significant energy savings. At ZIMALLOYS, the process consumes about 40GWhof electric energy per month. Apart from electrical energy, the company uses approximately 4,000tonnes of coke per month in the furnace charge and some 120,000 litres of diesel per month in pre-heating ladles.

ZIMASCO receives chrome ores from its own mines and tribute mines run by small-scale operators.The ores are transported to Kwekwe where they are blended with fluxes and coke. The process issimilar to that of ZIMALLOYS. ZIMASCO operates six submerged ore furnaces that treat chromeand ore induction furnace that treats briquettes manufactured from fines. The six submerged fur-naces consume 3,000 to 4,500 KWh/T of metal out of furnace and the power supply is fitted withpower factor correction units.

About 50% of electricity consumption in Zimbabwe goes to industry. Most of this energy is con-sumed in electric furnaces in the metal industry. The total capacity of electric smelters alone is esti-mated at 230MW. It is possible to reduce power demand in smelters by replacing electric arc fur-naces currently used in the country with coal fired plasma arc technology. Experience with coal-firedfurnaces is quite limited in Zimbabwe. The only technology so far tried commercially is an Austral-ian design Silo-smelt plant with a capacity of 2MW. This plant replaced an electric arc furnace in theproduction of high purity nickel at the Empress Nickel Mine. A 2 MW unit uses 2.5 tonnes coal/dayand costs USD590,000.

National Railways of Zimbabwe (NRZ)The railway system in Zimbabwe covers a total of 2,760 route kilometers. It provides the link totowns, farms and mining locations. The railway system comprises of a large fleet of locomotivesdriven by electricity, steam and diesel as a source of energy. In all cases the original source of suchenergy is the utilization of hydrocarbons contained in diesel or coal. The energy survey carried outbetween 1997-99 shows that there are three categories of energy (coal 36%, electricity 6% and diesel5%). From the survey, it is clear that diesel fuel constitutes the most important source of energy forNRZ and any energy efficiency evaluations should focus on this source of energy.

Bindura Smelting Refinery (BSR)The BSR is dedicated to processing of nickel concentrates and other nickel bearing materials withinZimbabwe. There are two main sources of energy in the BSR i.e. electricity for furnace smelting andtank-house electro-winning operations and coal for drying concentrates and steam generation. Smallamounts of liquid fuels are used for the transport fleet within the complex. Electrical energy is usedto power the various mechanical and electrical equipment such as the dryer, conveyors, converters,air blowers, etc. The 1997-99 energy survey shows that coal is the principal source of energy. Elec-tricity follows a close second with 44%, while liquid fuel only takes 1%.

Chibuku BreweriesChibuku Breweries is a Delta Corporation subsidiary. It is part of the Beverages group and is thelargest processor and distributor of sorghum beer brands in Zimbabwe. The subsidiary producesbetween four hundred and sixty four hundred and seventy million litres of beer per year. ChibukuBreweries’ main energy sources are coal, electricity with very little coming from liquid fuels. Liquidfuels are mainly used for the transportation of the product for marketing purposes. This will beexcluded from analysis in the main study. Coal is the major energy source used to fire burners in theproduction of steam that is used for heating and cleaning. Chibuku also uses substantial quantitiesof electricity to drive motors for the millers, stirrers and pumps. For purposes of this study, theHarare Brewery was used as standard since production process of all the breweries follow the samesystem with the only difference arising from better economies of scale. The types of the energy usedare as follows:

a. Coal - Coal fired boilers (2 x 7 tonnes)b. Steam - (i) Product Processing

(ii) Tank cleaning(iii) Packaging

c. Electricity - (i) Motors for milling(ii) Motors for stirring(iii) Pumps(iv) Filtration

Hippo Valley Estates - as a possibility for co-generation in the sugar industryHippo Valley Estates is part of the Anglo-American group that consists of a sugar mill and associatedcane growing estates located near Chiredzi in the Masvingo Province. Hippo Valley Estates have sixboilers with an average efficiency of (59-64%) for each boiler. The average annual coal consumptionis (11-14) tonnes per annum if all is well. Coal and bagasse are used at three boilers while the otherthree are completely coal fired for 2 weeks as from May. From June onwards there is a gradualreduction of coal until July when no coal is used any longer. The company consumes about 10MW ofpower at the plant and 4 - 5MW elsewhere on the estates.

The generation equipment is old and needs to be replaced. The boilers are old, of low pressure andinefficient in terms of baggasse conversion.

The Board of Hippo Valley has resolved to install a new 20 MW Generator set using existing boilers.They hope to co-generate power, feeding the excess into the national grid when its available anddrawing power from the grids as required.

Power Factor Correction for Bulawayo Pumping StationsThe two pumping stations (Ncema and Fernhill) pump treated water for use by the city’s inhabit-ants. Both pumping stations were upgraded in 1974 and 1990 so as to increase their capacity. Be-tween them the two pumping stations have 31MW of pumping capacity. The norm with pump sizingis to oversize motors by 10% as a safety margin for hydraulic failure. This reduces pump perform-ance because the motors are always under loaded. The lowered power factor can be improved byresizing motors or installing power factor correction. There is also value in assessing the viability ofusing synchronous motors for power factor correction.

MITIGATIONOPTIONS

FOREACHCASE

STUDY

CHAPTER

3

In this chapter the potential mitigation options are identified. Some preliminary data on the opportu-nities is given together with estimates of the potential greenhouse gas emission reductions.

ZESA

It is estimated that 85% of urban households are connected to the grid. Given that water heatingconsumes 33% of households’ electrical energy use, it is evident that the displacement of electricalheat can compliment to the electricity sector significantly. Electric geysers account for more than 40MWh of the national electricity demand and provide an option for end-use management. Solarwater heaters do not serve as devices for improving electric geyser efficiency but as alternative sourcesof energy.

Solar Water Heaters (SWH)Solar water heaters are generally equipped with better-insulated tanks such that heat losses fromthem are greatly reduced. The use of back up electrical elements would therefore meet with muchlower wastage when compared to the standard electric water heater made in Zimbabwe. Solar waterheaters on the market range in size from 80 to 300 litres. SWH consists of a collector’s panel andstorage tank. The tube and plate are placed behind the glass cover. The units have different configu-rations of collector and storage tank (integral, independent or no storage). The hot water storage ismade of copper, fiberglass, coated steel or plastic.

SWH are the most viable option for energy saving at ZESA. Solar water heaters have a potential ofdisplacing 33% of the energy used by households. This has the benefit of displacing 134.64Gw hoursof electrical energy per year. Another benefit of the SWH is a reduction of 341,000 tonnes of CO2 perannum, since electricity is derived from coal.It was calculated that replacement of electric water heaters by SWH has a potential market 130,000 by2010. The cost of replacement of electric water heaters by SWH is US$130,000,000.

Barriers to installation SWH are:

• High cost of investment• Lack of appreciation of SWH by both investors and consumers• Equipment malfunction and limited users of solar water heaters

Possible solutions include:

• Government providing an incentive scheme for SWH• Developing financial packages that are accessible to low and medium income brackets• ZESA purchasing and renting SWH to consumers

Time Switches

Sable Chemicals

Electrolysis PlantThere are alternatives to electrolysis such as:

• Coal gassification (deriving ammonia from anaerobic treatment of coal)• Coal bed methane (deriving ammonia from methane gas)

These options would consume less energy and hence reduce the amount of GHG gases, which areemitted during production of electrical energy.

Ammonia Synthesis PlantIt was found that if best practices were implemented at this station, there could be potential savingsof Z$67,644,000.00 per year. Ammonia is made from Hydrogen produced in the electrolysis plantand nitrogen from the air separation plant. The gases are reacted at high temperature in a catalyticmedium. The reaction is exothermic hence no fuel is required.

Nitric Acid PlantThe Absorption Column Efficiency Improvement Project is meant to improve the efficiency of theabsorption column in the Nitric Acid Plant. If implemented emissions can be reduced from 2000ppm to 200 ppm. The organization can also significantly reduce nitric acid losses and energy losses.Calculations indicated that about Z$686,000.00 per year can be saved.

Ammonia Nitrate PlantProject 1901 - Ammonia Nitrate (AN) Neutralizer Refurbishment involves replacement of old tech-nology with more efficient pipe reaction technology. The project can reduce Ammonium Nitratelosses amounting to Z$1.2 million per annum and also minimize emissions to concentration of Am-monium Nitrate in the effluent water. Sables is interested in implementing the projects.

However, several barriers to the adoption of energy efficient technologies at Sable Chemicals are asfollows:

• Lack of financial resources. The bankers’ interest rates are too high. At the same timethere is lack of foreign currency.

• Lack of government backing on some of the projects. The government does not offerincentives such as tax rebates or reduce duties when equipment is imported.

• Lack of locally available and verifiable resources for replacement technologies forexample coal bed methane would be a source of NH3 if economic reserves had beenverified.

• Lack of sufficient data to assess feasibility and viability of possible projects. Conductinga detailed audit is one way of gathering essential data.

ZIMASCO/ZIMALLOYS

Energy Saving Opportunities

a. Demand ManagementDemand reduction can be achieved by operating within optimal power factor and loadfactor levels. Maximum demand is inversely proportional to the load factor and powerfactor and hence can be reduced by increasing their values.

b. Operational efficiency improvement through electrode managementEfficient furnace operation, particularly its reliability and availability, heavily dependon electrode management. This is critical in determining production efficiency throughoutage loss reduction and energy cost reduction.

c. Minimizing or Eliminating reprocessingEliminating reprocessing for recovery of metal lost to slag will reduce overall energyconsumption and hence cost for the same levels of production output through minimizing re-cycling [re-melting] frequency.

d. Local Emission Abatement:An emission abatement project with a heat recovery component for preheating couldfacilitate reducing emissions both at source and at end use point.

Potential intervention projectsa. Furnace modification to an enclosed design to minimize heat loss and incorporating a

heat recovery facility for process material pre-heating.

b. Furnace power pack upgrading for increasing [production] capacity and efficiency.

c. Minimisation of chromium losses to slag through improving slag-alloy separation.

d. Optimisation of the reduction process

e. Local emissions abatement

f. Automation of furnace monitoring and control systems.

g. Strict adherence to documented recommended working procedures and good housekeeping practices.

Barriers IdentifiedThe barriers outlined in this paragraph pertain to only those intervention measures / or projectswhich have not received financial support approval from company management.

There are no barriers for most projects since internal financing has already been approved. Imple-mentation schedules have only been staggered to minimise production interruptions at a time whendemand for products is high and prices are lucrative. Potential CDM projects could support anyunimplemented projects.

The barriers identified in such cases include:

1. Lack of appropriate skills and know-how by operational staff2. Absence of stringent competition and hence no drive to invest in modern technologies

and state-of-the art equipment when profits are lucrative under a “business-as usual”scenario.

3. Absence of mechanisms to enforce strict adherence to recommended operational procedures without cutting corners.

4. Failure to make quality management an integral part of staff working habits.5. Absence of direct linkage between investment cost and revenue generation with reference

to local emissions abatement.6. Lack of confidence in poor performing high-risk technologies. Automation of one arc

furnace dismally failed to produce expected results and hence the reluctance to extendthis facility to other furnaces at Zimasco.

7. Operating capacity limitations. By design, small capacity furnaces have low efficiencies.Practically achievable improvements are therefore marginal.

8 Highly unstable internal macro-economic environment.Hyperinflation, escalating costs of money due to high interest rates.

9. Highly lucrative external market commodity prices.Priority is on production continuity.

10. Absence of real incentives for example from Government.11. Lack of capacity by law-enforcement agents to enforce environmental

legislation.12. Existence of customised, negotiated electricity tariffs. Maximum demand (MD) customers

would generally pay more if billed according to the standard tariff since MD constitutes70 - 85% of the bill. Zimasco is on a negotiated energy-based and sometimes commodity-price based tariff. There is no drive for additional measures to practise demandmanagement.

13 Existence of subsidised energy prices.The average international price of electrical energy is US$0.04 / kWh. The average forZimasco for 1999 was US$0.015 / kWh. The same applies for other fuels having animpact on electricity prices and hence real profit margins.

National Railways of Zimbabwe (NRZ)

A number of options intended to improve energy efficiency in the Railway transport system wasexamined. Although the earlier part of this study had shown the use of coal as being the most costeffective, its effectiveness in moving freight was poor.

The adoption of the Diesel Electric unit was considered the most desired choice. The idea was topick-up the latest version of diesel electric like DE11, which offers greater energy efficiency duringoperations once a particular speed has been reached.The current cost of purchasing a DE11, the latest Diesel Electric unit is estimated at Z$125 million perunit. The high cost explains why the NRZ has not been replacing the units earlier. Manufacturersrecommend that with good maintenance the units should be replaced every fifteen years and yetsome of the units in service are twenty years old.

The cost benefit analysis intends to compare the replacement of the existing diesel electric fleet basedon the most efficient ones. Unfortunately, the only benefit to be derived from the new units comesfrom savings in operations costs. In a new fleet of fifteen DE11 were acquired at the cost of $1,875million, it was estimated that savings accruing to NRZ per year would be $170 million with paybackperiod of eleven years.

Efficiency improvement in a railway system has to include operational and traffic management prac-tices. This was considered too complex for this study given the limited skills. As a result this casestudy was not developed fully.

Bindura Smelting Refinery

With the objective of identifying energy efficient technologies the study has come up with one sig-nificant one. It is proposed that the electric furnace currently being used to smelt nickel - copperconcentrates be replaced by a Flash furnace. The technology was developed by Outokumpu of Fin-

land for the same application. The main advantage it gives is that is utilizes an intrinsic energysource of energy.

The Flash Furnace utilizes sulphur in concentrates to provide fuel to run the plant. For the purposedof comparing the current Electric furnace technology and the possible replacement with the Flashfurnace an attempt was made to seek data on costs so that a cost benefit analysis can be made. Initialdata sourced indicates that the required investment cost for the acquisition and installation of theplant inclusive of an accompanying acid plant is Z$1650.00 million.

The cost of operating the electric furnace is Z$43.00 million per year in terms of electricity cost bear-ing in mind that all other costs remain at similar levels.

A payback analysis of the benefits of adopting the Flash furnace in place of the existing Electricfurnace suggests a return of capital taking 38 years to achieve. It becomes clear that the Flash furnaceas a more energy efficient technology is not cost effective in the case of BSR.A second technological option at BSR was examined after it was realized that the slag exiting fromthe furnace and going to waste contained considerable amount contained energy. The slag leaves thefurnace at 1380oC and cold water is sprayed on it in order to granulate the liquid slag.

The question being asked is whether the trapped energy can find use with the plant. After intenseanalysis it become apparent that there is no part of the plant that would require the energy levelscontained in the water. There is no known mechanism to trap the energy and utilize it effectively.

BarriersAmong the various barriers examined in the BSR it became clear that lack of investment capital is themajor constraint to the adoption of the Flash Furnace technology. Similarly, the initial capital isexcessive when compared to savings to be derived on an annual basis.

Chibuku Breweries

Energy Saving Opportunities

Coal

Boiler efficiency:(a) Control - the company is using boilers that are manually controlled, if automated, coal

consumption levels could be systematically controlled once there is a defined (air andcoal combination) for optimum combustion.

(b) Types of boilers in use could also be improved or replaced with more energy savingones.

(c) Steam, which is currently released into the air in large quantities in between productions can be re-cycled and provide savings.

Electricity(a) Motor gear efficiency(b) Timing of high-energy consumption against lowest energy cost times [i.e. scheduling

production in line with energy costing cycles.(c) Installed capacity versus plant output

Whilst Chibuku has not undertaken any mitigation options to reduce energy use other than the dailycoal monitoring usage by each brewery, or Power Factor Correction. There is serious considerationto engage energy consultants, possibly this year with a view to fully assess available options. Twostudies have previously been carried out, one under SADC Industrial Energy Management Project,the other by Steam Team. However, these were on a very broad energy consumption framework. Itis acknowledged more focused studies are necessary in pursuance of alternative technologies.

It is important to target energy efficiency measures particularly as energy costs continuously in-crease. Also both the company and the country stand to benefit from energy efficiency improve-ments translate to competitiveness and profitability as well as foreign currency savings.

Identified Barriers

Lack of informationWhilst the company interviewed demonstrated extensive awareness of environmental issues andrequirements, it was interesting to note that they were not aware of this programme or the benefitsthat could accrue out of such a programme. It was further noted that the company was not aware ofthe existence of the Climate Change Office or its functions. In short joint benefits to local environ-ment deriving from Climate Change mitigation have not been fully outlined and understood.What was evident was that the company as reflected by the industry in general is not readily willingto release information at times to the extent of loss of opportunities for free consultancy and advice aspresented by this study. It was easy to discuss and obtain very general information but when it cameto detailed information that could assist with more analysis there were too many barriers. This I seeas one of the major problems that face our industries and as such create a further barrier in accessingand utilizing information from elsewhere.

Hippo Valley Estates

IntroductionHippo Valley Estates is located in South Eastern Zimbabwe on 54000 hectares of land. The estate is amajor producer of irrigated sugarcane with about 11000 hectares planted. Apart from the sugarcanegrown on the Estate the company also receives sugarcane from small-scale growers in the Chiredziand Mkwasine areas. The company is owned by Anglo American Corporation who also have aninterest in a similar Estate West of Hippo Valley at Triangle. Both plantations have onsite sugarcaneprocessing plant with the main products being raw sugar, white sugar, molasses and cattle feeds. Thesugar mills include onsite electricity production from bagasse fired plant and are also connected tothe national grid.

Electricity supplied from the grid originates at Hwange and Kariba both of which are to the Northwest of Hippo Valley. The electrical power is transferred by 330kV lines, which link Harare andMutare to the power plant. A recent connection to South Africa is the preferred supply option forHippo Valley since this offers shorter distances to generating plant and a more stable grid arrange-ment for the regional electricity network. It is apparent that Hippo valley is located far from the mainsource of electricity besides the inplant generating plant.

The Sugar Mill

Hippo Valley Estates mills about 2.3 million tonnes of sugarcane each year. The milling season stretchesfrom early April to December. The total number of crushing days is about 258 each year. Milling is

done at 480 tonnes cane per hour with the sugarcane being trucked in from the fields. Each tonne of caneyields about 250 kg of sugar or 8.1 tonnes of cane are needed to produce a tonne of sugar (Table 3:1).

Table 3:1 Basic Production Information

Sugar production in tonnes 270537Cane Milled in tonnes 2.3mill tonSeason Apr to NovCrushing days 258Plant capacity cane per hour 480 TCHTonne cane per tonne sugar 8.1

About 270 537 tonnes of sugar are produced from the plant each year. This is about 50% of the totalproduction from Zimbabwe which for 1998 was 571 943 tonnes [Sugar Yearbook, 1999]. The millproduces about 655500 tonnes of bagasse per season. About 500000 tonnes of this bagasse is used forelectricity production after the installation of the new 20 MW turbo-alternator. Low-pressure steamfrom the turbine and from the pressure reducing valves is used for sugar processing at 550kg steamper tonne cane. As normal practice the boilers are operated at 65% as opposed to the optimum 81% asa way of disposing of excess bagasse.

Cane from the fields is fed into the mill through knives that cut it into millable size. The cane is thenshredded before it is fed into the diffuser where bagasse is separated from the juice. In total there aretwo feeding lines where per line the knives are rated 2000Hp (1.5 MW) and the shredder is ratedanother 1.5 MW. The diffuser can handle up to 300 tonnes cane per hour and each line has its owndiffuser. The bagasse is dried by drying mills, which bring the moisture level down to about 50%before it is sent to the bagasse store ready for power generation. The juice is pumped to a clarifier,which separates the juice from the solids. The solids, now in the form of filter cake, are sent to thefields as fertilizer. The filter cake contains lime, which is added before the clarifiers. The clear juice isthen sent to the evaporators where concentration is increased to 65% brix and the syrup cooled be-fore going into a storage tank. There are three evaporators, two with a capacity of 200 tonnes cane perhour and the third able to handle 400 tonnes cane per hour. The syrup is sent o vacuum filters wheremolasses is separated and sent to the distillery and cattle feed plant and raw sugar and white sugarare separated and sent out for delivery. The following diagram shows the mass balance for the plant.

Fig 3:1 Mass balance for Hippo valley Sugar Mill

WaterVapour

Bagasse660K ton

Waste Water Filter Cake8 KT

Cane2.3 mill’T

Lime2000 ton

Water

Raw Sugar255 KT

Molasses78 KT

Water flows are measured at source but there is no metering to determine process water input andwaste water discharged. Cane is about 70% water and 12% sucrose therefore some of the wastewateris actually recovered from cane. Water is recycled but make-up water is not measured.

Energy Use

Hippo Valley sugar mill uses coal, grid electricity, bagasse and firewood as the major energy sources.The plant also indirectly consumes diesel and petrol. The Graph below shows the annual energycontribution by fuel.

Fig 3.2: Energy balance for Hippo Valley Sugar Mill.

Source: Hippo Valley Estates Ltd.

Coal is used to provide electricity at mill startup and during the off season when bagasse is notavailable. Bagasse is also limited towards the end of the season hence coal use is increased. Thefollowing graph shows the energy mix through the year.

Fig 3.3: Energy Mix for Hippo Valley Sugar Mill

Source: Hippo Valley Estates Ltd.

Wood0% Coal

7%

Bagasse93%

0

200000

400000

600000

800000

1000000

Wood

Bagasse

Coal

Month

There are six boilers three of which are fired on bagasse and coal. These operate at about 36 to 38tonnes steam per hour but are rated 45 tonnes per hour. The largest boiler is rated at 100-ton steamper hour and is fired on 100 % bagasse. There are two other boiler operating at 68 tonne steam perhour on bagasse. The boilers are connected to a steam range of 30 bars and 400 deg C steam. This isfed to turbo-alternators producing about 25.5 MW. A throttling valve is used to feed the sugar millfrom the high pressure steam range since exhaust steam from the turbines is not enough for sugarprocessing. The steam cycle is closed with condensate being recovered from the mill and sent back tothe boilers.

M. J. Reid of the Sugar Milling Research Institute, Durban [South African Sugar Factory Plant Instal-lations, 1995] presented a survey of the plant installed in various sugar mills in the region. The spe-cific power figures that were presented help in comparing the relative position of a plant to that ofthe most common and/or average plant in the region.

The following table shows figures for some of the equipment with figures for Hippo valley shown incomparison.

Table 3.2: Comparison with Regional Installed Specific Plant Capacity

Plant Minimum Average Maximum Hippo Valley

Ratios Absolute

values

Cane Preparation [kW/tfh] 45 84.12 165 83.3 6MW

Diffusers [m2/tfh] 6.6 10.7 14.9 5.96 429.2m2

Milling tandems in Diffuser

factory [kW/tfh 38.3 60.3 110 41.7* 3MW

Milling tandems in Milling

factories [kW/tfh] 70 104.4 164 Non Non

Juice heaters [m2/tch] 4.29 8.0 13.1 5.64 2708.22m2

Trayless Clarifiers [m3/tch] .75 1.14 1.73 Non Non

Tray Clarifiers [m3/tch] 1.14 2.04 3.10 .30 146m3

Rotary vacuum Filters [m2/tch] 0.19 0.49 0.77 .24 114.15m2

Evaporators [m2/tch] 24.5 38.6 65.5 30.66 14716.5m2

Vacuum Pans [m3/tch] 1.25 1.52 1.9 1.83

Crystallizers [m3/tch] 2.2 4.04 5.4 3.18 1528.16m3

Boilers [kg-steam/tch] 516 778 1088 1054 506 ton/hr

Power Plant [kW/tch] 30 51.1 88.9 62.4 33MW

* not tandems

tfh - tonnes fibre per hour

tch - tonnes cane per hour

Source; Sugar Milling research Institute, Durban and Hippo Valley Estates.

In most cases the installation at Hippo Valley is just above the average specific nominal rating how-ever an assessment by a sugar-milling expert would be able to show the efficacy of the plant design.Average performance however implies potential for improvement through technology upgradingeven though figures on production cost given by Michael Matsebula of University of Cape Town[Development Policy Research Unit, Working Paper 01/50] indicate that Zimbabwe sugar mills have

the lowest production cost amongst the 20 factories that are quoted except for Guatemala. This im-plies optimum sizing of plant in the face of competition but does not differentiate between caneproduction and processing efficiency. Low production cost could therefore be linked to low costagriculture or incentives offered by government. A true reflection of cost in terms of energy efficiencywould be demonstrated by comparing the energy intensity of production.

Co-generation Project

Co-generation of steam and electricity in sugar processing is based on the balance of bagasse produc-tion in milling, steam consumption in sugar processing and demand for electrical energy. In the caseof low electricity demand excess bagasse is incinerated to reduce the nuisance factor. When electric-ity demand is a priority the steam demand can be optimised by improving the performance of steamheated plant so as to generate excess steam or to reduce the demand on bagasse. If the steam demandis high then the production of electricity is reduced. It has to be appreciated that for optimised use ofcapital the decision on the balance of processes is made at design and construction of plant. Once theplant is operational there is limited opportunity to vary operating parameters to shift the processbalance.

The following are some of the considerations that are made in optimising the design of a sugar process-ing plant.

• Production of high sugar and low fibre cane.• Minimising the energy intensity of cane preparation plant.• Optimising the performance of drying mills.• Optimising heat exchanger performance• Increasing evaporator area• Increasing filter area• Increasing steam pressure• Increasing boiler operation efficiency• Increasing efficiency of turbo-alternators.

This would be in addition to optimising the performance of discrete devices such as motors, lightingequipment, compressors and pumps.

The emphasis in this project is on cogeneration as the plant is already operating and new 20MWcogeneration plant has been installed. The consideration is therefore mainly for improvement of thesteam cycle where the following factors are important.

• Steam temperature and pressure conditions• Type of turbine - back-pressure, extraction-back pressure, extraction condensing and

straight condensing.• No. of units and modules• Grid interface conditions - voltage, and island operation or interconnected.• Tariff and load factor

In the case under consideration the least cost option in terms of increasing efficiency appears to beincreasing of boiler efficiency to the design level, which is 81%. At present the boilers are operating at64% efficiency, which is even lower than locally made boilers, which can achieve 74% efficiency. The

assumption is that it does not cost additional money to achieve the design efficiency. Once boilerefficiency is increased there will be excess bagasse, which can then be used for producing more elec-trical energy. Any accompanying measures such as improving insulation and reducing steam de-mand for sugar processing will achieve a higher electrical energy production level.

Another alternative to increase electricity production is the installation of higher pressure boilers.Operation at higher steam pressure increases the energy that can be extracted from the steam forelectricity production. The ejected steam is then used to drive the sugar plant, as it will be at lowerpressure. In this case the use of throttling devices such as pressure reducing valves has to be mini-mised or eliminated as it results in high-energy losses. This option is capital intensive as boilers andassociated plant and equipment would need replacement or reconfiguration. The benefit of the op-tion would be increased electricity sales, which may not be sufficient justification of the capital ex-penditure given the seasonal operation of the sugar plant. In all cases the marginal cost versus incre-mental energy sales will be the primary criteria for the decision. The investor may apply stringentrequirements on return on capital since electricity production is not core business.

Option 1

Improved boiler performance would yield a saving of 16% on bagasse, which would translate to anincrease of about 16% on electricity exports. Since there is no capital cost for this option the only costis the management of excess bagasse.

Option 2

Increased steam pressure would result in an increase in excess bagasse, which would be used forproducing electricity for export. The Indian experience Cane Cogen India, Jan 2001] is that an in-crease in steam pressure would yield the following increase in exported electricity.

Table 3.3: Increase of Output with Pressure

Steam pressure (bar) Export Electricity (MW)42 567 1387 29

Source: Cogen India.

The above figures assume the same volume of bagasse used in different cogeneration configurations.Hippo Valley is set to export about 5 MW. If the above estimates are used to project the potential forincreased generation at hippo valley it would be as follows.

Table 3.4: Interpolation of Potential at Hippo Valley with Increased Steam Pressure.

Pressure (bar) Export Power (MW)30 542 767 1587 31

The estimates are as accurate as the similarity in management and operation of the Indian plantcompared to Hippo Valley. It should also be noted that different configurations for boilers and tur-bines will result in different performance. In most cases more than one measure is taken to improve

the potential for cogeneration in a sugar mill. It is therefore difficult to link improvement to oneparticular measure in these case studies. The following are some of the typical measures and thepotential benefit. Some of these measures have been partially or fully implemented by Hippo Valley.

Bagasse moisture and Size Distribution.Bagasse moisture has a direct impact on heat rate as the moisture has to be evaporated before com-bustion. Size of particles determines the “spreadability” and “feedability” of the fuel. This impactson the combustion efficiency and flame speed. Also the volume of unburnt carbon in ash is a functionof bagasse particle size. Improved fuel quality can yield up to 10% overall efficiency improvement inmost cases

Steam and Power Generation EfficiencyThe unit performance i.e. the performance of the boiler, turbine and alternator is obviously a keyactor in energy conversion efficiency. Measures can be taken to improve fuel feed and combustionefficiency in the boiler. It has been demonstrated that 12%to 15% savings can be achieved in this area[Cogen India]. Control of combustion air distribution and excess air are some of the key boiler pa-rameters that can be optimised. In more capital intensive retrofits flue gas heat recovery can be im-proved.

High efficiency turbines can achieve up to 85% efficiency depending on whether they are back pres-sure or condensing types. They demand a higher capital input hence are more viable under powerexport arrangements.

Hippo Valley spent US$4.8 million on a new turbo-alternator rated at 20MW. The power produced isin excess of the 15MW required for factory and Estate. Another 29MW is available from older setsand it is estimated that about 10MW can be exported reliably from the whole installation. The com-pany also spent US$2.1 million on boiler refurbishment. The work included chemical cleaning, fuelfeeder refurbishment, super-heater replacement, and refurbishment of air heaters and grit collectors.

Reduction of Specific Steam ConsumptionOne ton of steam saved can yield as much as 125kW of extra electric power. In theory specific steamconsumption of 35% can be achieved as opposed to the current averages of 45%-50%. The case ofHippo Valley the specific steam consumption is given as 55%. About US$2.8 million was spent onreplacement of the bagasse conveyor system. This ensured reliable operation with minimal stop-pages due to fuel supply system failure. These stoppages had resulted in significant loss of product.

US$1.7 million was spent on refurbishment of evaporators and juice heaters. This was necessary forthe plant to realize the upgraded performance of the other plant.

Specific Power ConsumptionThe use of more efficient electric devices can yield higher values of export power. In addition toimproved load curves achieved through integrated control of sugar processes, the use of more effi-cient pumps, fans, compressors, gears and steam regeneration can avail more electric power for ex-port. Auxiliary power consumption can also be reduced by use of variable speed drives for forceddraft and induced draft fans on boilers. Such measures can achieve 20% to 30% reduction in con-sumption, which can be useful in the off-season. Measures have not been implemented to reducepower consumption except as a result of the work done on the fuel and steam systems.

Steam Cycle Parameters.Traditional thermodynamic theory dictates that higher inlet conditions and lower outlet conditionsyield more power extracted. Increasing steam temperature and pressure and reducing exit tempera-ture and pressure are capital intensive. Given that an average sugar mill has excess bagasse it is notdebatable why steam cycle parameters are not optimised in situations with constrained power ex-port conditions. In addition to electricity market conditions the length of season or availability ofalternative fuels would determine the scale of investment made to improve steam cycle parameters.It is correct to say all sugar mills can benefit from additional investment in improving steam cycleperformance if the tariff structures for export power are attractive. Hippo Valley has not committedresources to upgrading the steam cycle parameters. The main reason being that the existing installa-tion is adequate for the company’s co-business. Electricity production is an added benefit.

Dr G.C. Datta Roy of Power DSCL made a comparison of a plant about half the size of Hippo Valleywith and without the various efficiency improvement measures.

Table 3.5: Effect of Efficiency Improvement on Export Power

Parameter Unit Base Case Efficiency Case

Bagasse moisture % 50 45

Steam rate %cane 50 40

Power rate kW/TCH 33 28

Pressure-in bar 35 65

Temperature-in deg C 380 500

Pressure-exhaust bar 1.5 1.2

Boiler eff-GCV % 62 70

Return cond. Temp deg C 60 80

Tubine eff (BP) % 60 75

Turbine eff.(cond) % 75 85

Station aux % 9 7

Power gen MW 16.49 30.65

Power to bus MW 15.01 28.51

Power consumed MW 8.25 7

Export power MW 6.76 21.51

Specific export KW/TCH 27.03 86.03

The combination of plant determines the cost of a unit of electricity produced.

The overall unit cost is dependent on the cost of purchased fuel and the cost of capital employed.

Benefits of Co-generation at Hippo Valley.

System support for the grid;• Hippo Valley is situated towards the Eastern border of the country. The generation plant

supplying the grid is situated to the West of the country. This means the sugar mill is a generationoption at the end of the transmission network. System performance is therefore improvedsignificantly by the installation of a power source at a location away from other sources.

An assumption can be made that system losses are at least 10% for loads near Hippo Valleygiven that the average losses are about 10% for the grid and distribution network combined. Akilowatt-hour generated by Hippo valley is equivalent to 1.1-kilowatt hours generated by thesystem. Given that the utility, ZESA will only consider buying the metered energy from HippoValley, the losses reduced would be an added benefit. If the full production of the sugar mill isconnected to the grid the system support offered by the introduction of “electrical inertia” at theend of the grid would improve stability of the interconnected system. It may be argued that thesupport would be small but in an emergency the Hippo valley power plant could offer up to40MW of generation that could easily lessen the burden on the national grid. If the technicalconsiderations are made properly some non-essentialloads could be dropped at Hippo Valleyto offer this support. The reverse would be true for a situation where Hippo Valley losesgeneration. Parameters needed to quantify these benefits would be cost of lost production atHippo valley and cost of lost supply for the system that could be supported by Hippo Valley.The Hippo Valley suger mill process flow diagram is presented in Fig 3.4.

Displacement of imported power and energy;• Zimbabwe imports electricity from South Africa through the 132 kV link at Beitbridge. The link

is able to deliver 40MW. If Hippo Valley is connected to the grid any energy and power suppliedby hippo Valley could be used to displace imports from South Africa. This is conditional to thesupply agreement with ESKOM of South Africa where any minimum load factor requirementswould have to be complied with. Since Zimbabwe pays for imported electricity in hard currencythe relief on imports would reduce the burden on the foreign exchangesupply.

Increase of renewable energy in the national energy balance;• Sugar bagasse offers a good opportunity for cleaning the coal intensive electricity sector in

Zimbabwe. Bagasse is obviously a much lower cost fuel and its use would help in reducing thedemand for coal mining. It maybe argued that coal mining offers employment but incrementaldemand would result in increased pollution levels which would have to be offset against theimpact of acid rain on the agricultural sector. Also operation of a renewable energy option as amain supplier of grid electricity would give Zimbabwe the much needed experience to attractinvestment in power generation by renewable energy especially biomass. The experience wouldbe in terms of tariff agreements, legal framework, technical expertise as well as technologymanagement.

Displacing 5MW of electricity from coal would result in a reduction of about 39000 tonnes ofcarbon dioxide emissions from coal combustion. This does not including the reduction ofemissions due to coal transport. If the export potential of the plant is trebles the potential reductionwould be 117000 tonnes carbon dioxide per year.

Design of a framework for independent power producers;• Zimbabwe has experience with the connection of a micro-hydro scheme to the grid. This is with

the 750kW plant at Rusitu in the Eastern Highlands somewhat close to Hippo Valley. This exampleis however much smaller than the proposed supply by Hippo Valley. Even the initial 5 MW thatHippo Valley can spare is sufficient to initiate discussion with the utility on supply contracts.The potential of 30MW is large enough to draw government attention to the need for a robustindependent producer legal framework. It should not be forgotten that hippo valley is less than30km from Triangle, another sugar mill with a similar potential for electricity export. A thirdsugar estate is planned at Chisumbanje which is North East of Hippo Valley but within 100 km.Given that Chisumbanje will be much bigger than Hippo valley and Triangle combined it is fair

to estimate a potential 100MW or more of sugar co-generation in the area. This makes itworthwhile for Government to start working on a framework for independent power producers.

• The sugar mill would benefit from additional revenue from sale of electricity. If the tariff isviable then the company should be able to justify the additional capital invested in electricityproduction. This is not yet certain, as no firm price has been arrived at yet. If the total capitalexpended up to now is attributed to electricity production this would be US$12.72 millionincluding US$.57 million for the transmission line. This is equivalent to US$2544 per kW. Thisfigure is for a partial refurbishment. If the plant was installed as new the cost per unit would bemuch higher than that for a coal fired utility plant that averages US$2500 per kW.

Barriers to Power exports from Hippo Valley.

The case of electricity export from Hippo Valley Sugar Mill into the grid is unique in that it presentsa case in progress. The Sugar Mill has made investment into improving the cogeneration plant so asto be able to meet the reliability levels of electricity supply to the grid. The plant management hasalso held discussions with the utility to negotiate a supply contract and even though not ideal, theyhave secured an agreement to sell their excess power to the grid. The question is now to create anideal environment for the Government and Zimbabwe to realize the benefits of increased electricityproduction at Hippo Valley. The following is a list of some of the barriers to this opportunity.

Absence of a Legal Framework to Guide Negotiation of a Power Purchase Agreement.The utility ZESA has the mandate to provide least cost and reliable electricity to the Nation. The legalframework under which ZESA operates also tasks them to regulate the production of electricity byindependent producers. In the absence of previous experience with IPP’s ZESA tends to be overprotective when negotiating supply contracts. This costs open discussion on cost minimization anddevelopment of private investment in the power sector. Given the benefits that accrue to the economyin general it is prudent that Government develops a guideline for the negotiation of power purchaseagreements between the utility and private producers. The new Electricity ACT may account for thison the legal side but a technical document that guides the negotiations would still be needed.

Absence of a Technical Framework for Aiding Private Companies in Developing Projects withSocial Benefits.Hippo Valley Estates is a sugar producer and will not invest excessively in electricity production.They may have the fuel but will only invest in electricity production as far as it aids the sugar millingprocess. It is therefore not expected that the company will commit large volumes of resources bothstaff time and money to develop a project that at the end can only benefit from a pricing system thatis sensitive to social needs of the country. If the Government would avail a framework where techni-cal support would be granted the sugar mill for the purpose of optimising electricity productionfrom the sugar mill with the understanding that the power plant can be a stand-alone business thatsupplies steam to the sugar mill and generates revenue from electricity sales to the grid and also fromgovernment contribution towards the social benefits realised from the process. The social benefits arein terms of a cleaner energy source and a lower demand on public capital for power production.Government contribution can come in the form of fiscal and other incentives. Even though technicalknow-how is resident in the private sector Hippo valley is not expected to source or allocate theseresources beyond their core-business of sugar production.

Technology Barrier

Interconnection of the cogeneration plant and the grid requires the installation of a transmission lineand equipment to minimise the negative impacts that mulfunction from both systems can have oneach other. This calls for technical input that is not currently resident in the sugar mill or in ZESA.There would therefore be need for conversion of skills from pure utility or pure sugar co-generationto grid connected sugar-cogeneration management. Such conversion of skills is almost a prerequisiteto a successful power purchase agreement. The conditions for reliability place this on the sugar milleven though the requirements for system stability would be a burden for the utility engineer in asituation with legal guidelines for acceptance of the IPP. This a clear case for enabling activities wheregiven the climate change benefits the GEF or other UNFCCC mechanisms could be mobilized tosupport the development of skills. Transaction cost for such skills development may hinder the de-livery of clean energy at a competitive price.

Inability to Assess and Account for National Benefits in a Private Investment.

The fact that Hippo Valley has been struggling almost without support to lend a PPA outside theirnormal business highlights the weakness of support strucutres for such investment. The main ben-eficiary of the investment is by all means the public sector. Given the low cost of bagasse and the highnuisance factor Hippo valley could simply confine their interest to sugar production with bagassedisposed of as a waste. The added value of electricity sales and the future benefit of a potential IPPbusiness may not be urgent enough to demand the allocation of scarce resources in a difficult envi-ronment. The first contact that Hippo valley made with the public sector ie ZESA, should have trig-gered a mechanism to support the development of a project that clearly holds major benefits forGovernment. This would have happended if such benefits were apparent to ZESA under directionfrom the sole shareholder, Government. Since the benefits are obscure to the public sector representa-tives to an extent sufficient to drive a process for development of a legal framework and urgentsupport it is important that the key stakeholders formulate a programm to highlight the benefits anddevelop skills for the realization of such benefits. Ministry of Finance and Economic Development aswell as Ministry of Environment and Tourism are the key players here with technical support fromMinistry of Mines and Energy.

Inability to Assess the Potential Benefit from CDM

The low levels of Foreign Direct Investment is the key reason for the economic difficulties faced bythe country. Sugar co-generation holds the key to attracting such investment since it is a proventechnology which offers the benefits needed for the reduction of human impacts on the climate sys-tem. Technology is under devevelopment that can double the production capacity of an averagesugar-cogeneneration plant. Given the progress being made in the UNFCCC process on financinginvestment in developing countries it is prudent that Zimbabwe takes interest to develop sugar-cogen as the initial development will highlight the viability of the business and committment by thecountry to cleaner technologies which are the main factors required to attract the additional invest-ment in technology that will yield quantifiable climate benefits as well as additional investment forZimbabwe.

As The Ministry of Environment and Tourism represents the Government at the Conference of theParties, it would be beneficial for this project to be sold as one of the opportunities for investment inZimbabwe.

Fig 3.4: The Hippo Valley Sugar Mill Process Flow

Bibliography;

1. Cane Cogen India, vols IX, X, XI,2001.

2. Sale of Power to the Grid: Challenges Faced by Sugar Factories in Zimbabwe, A Casefor Hippo Valley Estates Ltd, S.D. Mtsambiwa, Aug 2001-09-18

3. Renewable Energy, Sources for Fuels and Electricity, T Johansson, H. Kelly, A.K.N.Reddy, R.H. Williams, L Burnham, Island Press, 1993.

Power Factor Correction for Bulawayo Pumping StationsBulawayo Ncema Water Works

Introduction.

Bulawayo is the second largest city in Zimbabwe with a population of about 1 million. The city islocated in the South of the country in a semi arid zone with low rainfall. Water supply is a criticalissue for Bulawayo with frequent droughts making the city prone to water shortage. Plans areunderway to pipe water from the Zambezi but at present the city is supplied with water from storagedams and an aquifer all no less than 40 km from the city.

Boilers (30 bar, 400 deg C Alternators (25.5 MW)

Cane Knives Diffuser

Filter Cake fromClarifiers (to fields)

Heaters

Clarifiers

Heaters

PressureReducing Values

Evaporator

Melt TankSyrup Tank

RefineryCentrifugals

Dryer

Raw

Cattle Feeds Crustalizers

VacuumPans

Melter

White

Dryer

The Water Supply Network.

Bulawayo has access to water from 7 reservoirs. Six of these are municipal dams, one, Insiza, is agovernment owned dam with 75% of the water allocated to City of Bulawayo and the last is anunderground aquifer in the Nyamandhlovu area. One of the dams is too polluted for use since it wasused for recycling sewage water and with limited rains the concentrations are too high for conven-tional treatment.

Upper Ncema dam feeds lower Ncema by gravity and the then flows into the treatment works.Umzingwane gravitates into the treatment works but has capacity to pump water to increase flowsduring high demand periods. Insiza dam feeds Inyankuni dam by gravity and the water then pumpedinto the treatment works at Ncema.

Raw water is passed through an aeration tank where the water is splashed onto baffle plates. Theoxygenated is pH corrected by addition of lime and then flocculated with Aluminium Sulphate. TheAluminium Sulphate is brought to the plant in bags and about 800 bags are used per month. Theflocculated water is passed through some settling tanks, two of which are rectangular and four arecircular. Once the sludge settles the water is passed through sand filters where the rest of the sludgeis removed. There are two clear water tanks which hold the finished water before it is pumped toFernhill pumping station and onwards to Bulawayo. Before final transmission the water is chlorin-ated and also ammoniated as a way of increasing the residents time of chlorine in the water. Chlorineis added before and after filtration.

List of Major Energy Plant - Pumps

Table 3.6: Ncema

Item Motor Pump Delivery

Clear water pumps 2x450kW, 6.6kV 2x size 42 AEI pumps 760LB

8x 360kW, 6.6kV, 8x size 37 Sulzer pumps 760LB

Metro Vickers

Raw water pumps 3 x 2MW (unknown make) 3xKSB 1739m3/h at 240m

3x2.2MW 6.6 kV GEC 3x Sulzer HPDM 350-570,

Alsthom, 225A 1859kW .63m3/s

Table 3.7: Fernhill

Item Motor Pump Delivery

Clear Water 7x450kW, 6.6kV Bruce Sulzer size 42 800LB to Tuli

Peebles

Raw Water 3xGEC Alsthom 2.2MW, Sulzer HPDM 350-570, 250m head at

6.6kV 1859kW .64m3/s to

Criterion

3x2MW (unknown make) 3xKSB 240m at .6m/s

The motor-pump sets as standard procedure are designed with 10% more motive power than pumpabsorption. This is to account for on-load start-up and potential overload from pipe breaks and othercontingencies. This means under normal operation the motor is under loaded. In addition the motorsat Ncema and Fernhill are provided with protection relays. These are set to trip the motors on over-load and on detection of internal faults.

Mass Balance for Water Works

Sand filters are subjected to backwash once every day. The backwash water is discharged to wastetogether with the sludge that is removed from the settling tanks. In addition to backwash water therewas clearly visible a stream of leakage water which is also discharged to waste. Wastewater is re-leased into the river. Estimates are that 5% to 6% of treated water is lost to waste during good weatherwhen the raw water quality is good. In rainy weather this figure goes up to 10%. Given that the plantreleases about 1652m3 of clear water per hour the waste can be a significant volume of water. Up to165m3 per hour of wastewater can be produced. During the plant visit the technical staff from the citywere preparing annual budgets and one of the items was a water recycling arrangement for thewastewater.

Opportunities for Energy Conservation.

Pump-Motor sizingDespite the concern that motors can be overloaded by hydraulic failure technology is available thatcan manage this circumstance. Motor protection can regulate speed or switch-off the motors in thecase of overload. Most of this protection is already installed at Ncema and Fernhill. Needless to saythat in standard motor design a 10% overload capacity is already included to accommodate shortduration overload. It would unnecessary to add another overload capacity on the rated load espe-cially for centrifugal pumps where the maximum loading is achieved at rated speed.

Power factor for a motor depends on the proportion of excitation current to load current. In the caseof oversized motors the excitation current is a bigger proportion than the designed ration hence thepower factor falls. Given that the metering installed for maximum demand customers measures re-active power it means the user of under-loaded motors is penalized for poor power factor especiallyat peak load.

Waste water reclamation and leak repair.To a great extent wastewater is not a direct energy loss at Ncema. The water is mostly gravity fedfrom the storage dams. However if the capacity of the dams is considered as well as the energyrequirements for water treatment chemicals and facilities, water loss can be linked to energy waste.Bulawayo has a limited water supply and a project is planned to pump water from the Zambezi. Ifthis is included in the analysis the energy/water relationship becomes even clearer hence water con-servation is directly linked to energy conservation.

Power factor correctionIt is the nature of electrical devices that have wire windings such as motors and transformers that theenergy they consume is split into two components. One component is the energy needed to do thework and the other component is the energy required to induce the magnetic field that enables thedevice to work. The difference between the two is that the magnetizing energy does not produce realwork but commits the energy supply system to supplying the energy flow. The ratio between the two

components of energy is defined in terms of power factor. The technical definition is that the magnet-izing power does not produce useful work and is therefore measured in volt-ampere-reactive, Var.The energy that produces work is measured in watts. The two components add up to make volt-amperes, VA. Power factor is a measure of the relative effect of each component on the total. Thehigher the power factor the greater the work producing component and the lower the power factorthe greater the undesirable component or the magnetizing component. Increasing power factor canbe done by optimizing the design of the motor driving the pump as well as making sure it is workingclose to or at it’s full rating i.e. the useful work is maximum. Since any motor has to draw somemagnetizing current other devices can be added to the system to generate this magnetizing currentso that it is not supplied by the utility. Metering used by the utility measures and charges for thismagnetizing energy. Such devices are termed power factor correcting equipment and they includecapacitors, synchronous motors with appropriate exciters and rotating motors which do not driveany load but similar to synchronous motors can compensate for poor power factor. The least costoption is the installation of capacitors. However capacitors have the shortest life and tend to mal-function more easily.

Power factor correction is installed at Ncema and Fernhill. The assumption made in installing theequipment is that the compensation should meet the requirement of the average pumping load. Adifferent arrangement would have been to ensure that each motor has sufficient correction for whenit operates. This would however entail idle equipment when pumps are out of service due to lowdemand or during maintenance. It has turned out that power supplies frequently experience inter-ruptions that force increased pumping during shorter periods as a way of compensating for losttime. In this case the power factor correction is no longer sufficient to meet the requirements. In suchcases the power charges are high due to increased demand. Since the utility has limited supply ca-pacity the tariffs used emphasize on demand charge and the electricity bill is mostly charges fordemand as opposed to consumption. The following graph serves to illustrate the inadequate powerfactor correction.

Fig 3.5: Fernhill Power factor Variation with Demand.

The above graph shows a power factor of .9 when the peak demand is about 7MVA. Given that thepump motors have a rated power factor of about .89 it shows that the pump station has a very limitedpower factor compensation capacity installed. A similar situation is evident for Ncema as shown inthe next diagram.

Nov Dec Jan Feb Mar May Jun Jul Aug

8

7

6

5

4

3

2

1

0

0.98

0.96

0.94

0.92

0.9

0.88

0.86

MD PF

Fig 3.6: Power Factor Variation with Demand at Ncema.

The above figures are for the year 2000. The City is conducting an energy efficiency study and it isprobable that they will upgrade the power factor correction equipment. Once improved high powerfactor results in a higher load factor which would yield optimum returns for both the utility and theCity. The energy intensity for water pumping would be reduced and the maximum demand wouldalso be reduced which is the intention of the utility when applying a demand charge. If the powerfactor was to be improved from the .9 level to about .98 during peak demand the size of capacitorsrequired for each pump station would be about;

KVAr = kW(tan(1-tan(2).9x7(.48-..20)x1000 = 1772

Where ( represents the power factor before and after correction and kW represents the power re-quired to do the work. In practice the calculated value is augmented by extra capacitors to allow forfailure. In addition to the capacitors there will be need for switches that connect and disconnect thecapacitors as the power factor varies. The utility does not allow for power factor above 1 as thisrequires that the transmission network carries the excess reactive power to the next reactive load onthe system or to the power station.

Power factor correction is an energy efficiency improvement measure in as far as it;

• Reduces the demand on the utility system hence defers use of less efficient plant.• Reduces the line current on the supply system hence reduces losses due to line resistance.

Power factor correction is therefore often considered a bill reduction option with limited energy usereduction. The interest of the energy user is therefore for the purpose of reducing the fees charged bythe utility whereas the supplier has the real interest of optimising use of capital plant. In extremecases poor power factor can affect system performance in terms of voltage stability and immunity toblackouts.

An effective scheme for Ncema and Fernhill pumping stations would be to analyse the load curve forthe pumps on an hourly basis over a week, a month and over a season. This analysis will highlight

Nov Dec Jan Feb Mar May Jun Jul Aug

8

7

6

5

4

3

2

1

0

0.96

0.94

0.92

0.9

0.88

0.86

0.84

MD PF

0.98

1

1.02

the pump commitments and the variation of power factor with time. It is probable that dedicatedpower factor correction equipment connected to each pump motor and switched together with themotor would reduce the cost of the scheme and be much more effective than the switched capacitorsin a central bank. Elimination of individual switches will reduce the cost by nearly half depending onthe type of switch that is used. It may also be possible to reduce the cable length by attaching thecapacitors to the pump motor. This work requires a more detailed study but the results would createsignificant benefits for the City Authority

High efficiency motors

High efficiency motors are normally associated with small motor applications. Large motors tend tohave high efficiency levels due to the more significant capital commitment and the operating cost interms of energy use. The pump motors at Ncema and Fernhill range in size from 300kW to 2.2 MWand have efficiencies of around 96%. It maybe possible to increase the efficiency to 98% but the addi-tional capital needed to buy the new motors may not warrant the upgrade. It may be better to ensurea high standard of maintenance and an optimum commitment scheme instead of individual deviceefficiency. On pump replace the efficiency levels maybe considered for the new motors.

Variable Speed Drives

Pump speed is a major parameter in determining energy use. Pumps are designed as fixed speeddevices but variation of speed in centrifugal pumps is directly proportional to delivery volume. De-viation from design speed also increases pump losses. However an analysis of the pump characteris-tics may show the possible speed regulation scheme that can impart a continuous variation of thedelivery rate in response to demand. The stepped characteristic of the current mode would then bereplaced by a more optimised continuous mode that allows the next pump to pump at less thanmaximum capacity if the demand is not high. This is valid only if the storage capacity for raw waterand clear water is not sufficient to cushion pump capacity in times of failure.

Pipeline Losses

The water pipeline from the two pumping stations was installed when water demand was low. It ispossible that energy losses are now high due to the need to increase head and flow rate to meet waterdemand. In such a case the use of low friction pipes or larger diameter pipes would be a way ofreducing energy losses. A short-term measure would also be to reduce flow velocity by operating ata constant pumping rate but for longer hours.

Opportunities Identified in this Study

Table 3.8 gives a summary of the options identified above.

The above options were identified on the basis of discussion with plant operators as well as throughreference to previous studies. In the case of the National Railways no option was identified in thestudy but it is known that electrification of the network, improvement management of the networkas well as improved plant maintenance can achieve significant savings given the historical perform-ance of the network.

In the case of Bindura Smelting and Refining the option that was identified could not be assessed dueto lack of data. The option was to do with recovery of excess heat from the smelter.

Table 3.8: Cleaner Technology Opportunities Identified in Study

Company Name Main Activity Opportunity Identified

ZESA Electricity Utility with • Replacement of Domestic electric water heaters

generation, transmission with solar water heaters

and distribution • Installation of time switches on electric water

responsibilities heaters

• Demand side management through device

efficiency

Sable Chemicals Ammonium Fertilizer • General improvement in air separation plant

Production through performance

electrolysis of water. • Displacement of electrolysis by alternative

technologies using coal

• Use of coal bed methane in-place of electrolysis

• Improvement of absorption in nitric acid plant

• Refurbishment of ammonium nitrate neutralizer

plant

• Energy recovery from ammonium nitrate

neutralizer plant

• Energy demand management

• Boiler efficiency improvement

• Refurbishment of cooling towers

ZIMASCO Ferrochrome Smelter • Improvement of plant load factor

• Improvement of furnace electrode management

• Reduction of metal lost to slag

• Waste heat recovery

Zimalloys Ferrochrome smelter • Upgrading of furnace power supply

• Improvement of slag-alloy separation

• Improvement of ore reduction process

• Automation of furnace controls

Bindura Smelting Nickel Smelter • Smelter technology up-grade

and Refining • Steam/electricity co-generation

National Railways Rail Transport • Improved traffic management

of Zimbabwe • Electrification of the network

Chibuku Opaque Beer Brewery • Boiler efficiency improvement

• Electric motor efficiency improvement

Hippo Valley Sugar Plantations and

Estates Milling • Electricity and steam co-generation

TECHNOLOGYASSESSMENT

CHAPTER

4

Identification of Opportunity:SurveysCase StudyStandardsLegislationTechnology Options

Project and ProductDescription

Assessment of inputs:Material BalanceMarket for Associated productsAlternative Market for InputCost of Access

Risk Assessment;BarriersLinkages

Assessment of Benefits;EnvironmentOther SocialFinancial/ FiscalEconomicIntellectualOther Development

Technology Sizing;CapacityLifespanCostOperational

Technology Description;ProcessesProductsAccessTechnical EnvironmentEffluent/ EmissionsFuels/ Other InputsCompeting Technologies

Methodology for this Study

This study was structured so as to identify technology options for selected industries and to assessthese for cost and benefits. The concept is to assess the barriers to implementation of win-win tech-nologies. The concept of win-win requires that the cost and benefits be assessed from the environ-ment perspective as well as from the investor perspective. Since the question is why technologies arenot implemented emphasis will be placed on the financial cost as opposed to economic and socialcost. Industrial investors usually make their decisions based on cash flow and financial benefit asopposed to national or economic benefit. The analysis will however acknowledge any policy barriersthat may exist. The following model will be used to assess technologies under this study.

Fig 4.1: Analytical Model Used in Study

The following description explains each box and the analytical requirements for the indicated infor-mation.

Identification of OpportunityThe opportunity for implementing cleaner technology is identified through an audit. The industrialaudit would include a discussion with the plant management on the areas needing improvementand on the technology options they will have considered for implementation. Previous experienceand reference to case studies will be essential in making these assessments. Since the studies were notstructured to generate new data it was not possible to install metering equipment and record per-formance data for existing plant.

The identified option should take into account current and known future legal requirements forplant operation. It is also important to refer the technology to recommended standards and expectedperformance levels.

Project and Product Description.This step completes the definition of the analytical boundaries for the process. This is separate fromthe analytical boundary for the technology. The concept is to define the inputs and outputs so theycan be compared to an alternative process. The advantage of looking at a process is that in a largeindustrial plant it may not be possible to look at the whole plant with one technology option and thencompare it to the whole plant with a different technology. The analytical requirements may be toocumbersome and the level of accuracy and meaning would be lost. An example is the production ofelectricity in a sugar mill where improvement of boiler performance could be assessed by drawingan analytical boundary around the power plant where input is bagasse and technology and output iselectricity and emissions.

Technology DescriptionThis section defines the operational parameters of the technology. It also gives the product quality aswell as the effluent from the process. In addition to the operational parameters the section also ex-plains the technical skills required to operate the technology in terms of operator and maintenancesupport. Competing technologies are also given here together with the key performance differences.Access to technology is also discussed with major barriers highlighted.

Assessment of Inputs.A material balance is an important tool for assessing environmental impact. It also evaluates theefficiency of the process and the magnitude of material handling plant that is required. In caseswhere alternative markets exist for the inputs there will be need to assess the potential disruptionthat can be caused by growth in alternative markets and guarantee of supply. This may not apply tocases where the technology improvement does not change the raw material used. Cost of access toraw materials including social and political cost should also be analysed.

Technology SizingTechnology sizing is an important factor where the technology is supplied in modules. In some casesthe size has a great influence on price per unit hence it may be important to considered sizing sepa-rate from the expected plant size. A larger size may mean expanding the plant or changing opera-tional regimes.

Risk AssessmentRisk assessment is a wide subject with coverage over social, political, legal, technical, supply andperformance issues. There is no specific formula for compiling this information other than referenceto experts or third party documentation.

Assessment of Benefits.Benefits are qualitative and quantitative. Quantitative benefits are converted to financial terms andqualitative benefits include social and other benefits which are described. The weight place on eachbenefit depends on the perspective being taken in the analysis. This assessment includes computa-tion of net benefits after subtraction of cost.

Selected OptionsThe following promising options were selected at a project workshop held in October 2000. Theselection was based on preference of participants supported by brief discussion of the benefit of theoption. The following is a list of the selected options in order of priority.

Table 4.1: Options Selected by Stakeholder Workshop

Company Selected Estimated capital Estimated Estimated US$/ton CO2

Opportunity Cost (USD) Annual CO2 savings

Energy Savings

ZESA Solar water 130 mill 166075MWh 280Gg 4.0

heaters

ZESA Geyser time 5.2mill 150GWh 24Gg 22

switch

Chibuku Boiler .24mill 64800GJ .615Gg -8

and Sables Efficiency

Improvement

Hippo Valley Electricity/ - - - -

steam

co-generation

Sables Ammonia from 13.5mill 747GWh 1141Gg -12.3

coal bed methane

The above opportunities have been assessed previously either as climate change mitigation optionsor as energy efficiency improvement opportunities. However none of the options has been takenthrough an implementation program. During the surveys for this project some barriers were men-tioned by the industrialists as the major reasons for not implementing the technologies. The follow-ing is a list of the barriers identified under this study:

• Lack of awareness on opportunities• Inability to assess and appreciate benefits• Perceived long term repayment periods• Incorrect tariff signals

• Constrained market hence higher capital cost of devices• Poor awareness on technology operation• Absence of incentives• Absence of financing schemes - low cost capital

General Barriers Faced by Zimbabwe Industries

Table 4.2: Classification of Barriers on Industrial Energy Efficiency

Barrier Group Sub-barriers

Inadequate appreciation of • Poor analytical skills - policy and technologybenefits of efficiency • Limited awareness on technology informationimprovement to be forceful on • Inability to lobby for policymeasures • Absence of technical support

Absence of technical • Poor market assessment skillsfallback- consultants • Insufficient information on contract procedure

• Inability to define business plans• Absence of low cost finance• Limited marketing to external investors

Immature market • Limited demand for technologies• Absence of technology market information• No low cost finance• Inability to benefit from existing financing schemes e.g.

AIJ and CDM

Weak Institutional framework • Umbrella bodies not familiar with efficiencyimprovement business

• Financing institutions limited on efficiencyimprovement business information

• Absence of energy efficiency promotion and supportinstitution

• No legal framework to press for efficiency improvement

Absence of analysis of joint • Cross sectoral benefits not documentedbenefits of efficiency • Related institutions are not participating in programsimprovement • Stakeholders ignorant of magnitude of joint benefits

Pressure from competing • Economy not conducive to performance improvementfactors • Investors more keen on survival than improvement

• Short term benefits of efficiency improvement notunderstood

• Efficiency improvement carried out on a project basis not

program basis with long term relevance

Integration of barriers as shown in the above table highlights the importance of a program approachto efficiency improvement which is applicable to technology up-grading. The framework for imple-mentation of cleaner technologies needs to be present for the stakeholders to be able to identify andadopt appropriate measures as an integral part of their investment program. The project approachhas been taken by government in identifying the opportunities to do the following;

• Produce ammonia from coal• Produce automotive grade ethanol from molasses left in sugar processing• Produce petroleum fuels from coal• Develop and use coal bed methane• Encourage the use of coal by rural business as opposed to tree felling• Develop mini hydro plant at irrigation dams

The fragmented approach to problem solving has to some extent limited the adoption of the businessopportunities by investors from other sectors of the economy other than energy. The structure of theenergy sector legislation has also discouraged entry by new investors hence some of these innovativeideas remain on the drawing board. The electricity ACT has not been clear on the treatment of inde-pendent power producers and the energy sector does not provide guidance on the commercial devel-opment of other fuels such as gas and coal derivatives hence the foreign investors who have thetechnology and capital remain outside the sectors despite the presentation of evidence for potentialbusiness.

Energy pricing has remained a controlled mechanism for supporting the low income and the energysector is as such dominated by public companies. The use of subsidies to support the energy compa-nies has therefore discouraged creativity in terms of opening up of new business areas in the energysector such as Energy Service Companies and co-generation. This is now being addressed by theopening up of the energy sector to private investors. This however takes away the utility responsibil-ity for demand side management unless legislation obliges utilities to implement efficiency improve-ment programs. The end user will otherwise be left alone to identify and implement opportunitiesfor efficiency improvement as a cost cutting strategy. This will however not necessarily mean envi-ronment protection as measures such as load factor improvement dominate the end user activitiesbut have limited environmental benefit.

Recommendations for Technology Implementation.

Generic RecommendationsThe process of introducing new technologies is multi-pronged. It is difficult to predict the outcome ofan initiative on clean technology especially in an environment that is limited on the culture of tech-nology evolution. Zimbabwe has had some experience with technology innovation but with differ-ent levels of political and economic motivation. Local initiatives have resulted in the construction ofan ethanol plant fed on molasses from sugar processing. Other public sector innovations include useof coke oven gas to displace diesel in a coal fired power station and introduction of prepayment andother electronic meters to encourage energy conservation by household and industrial electricityusers.

The private sector has not been negative to technology improvements. Examples of private sectorinitiatives include use of passive solar energy in conditioning space in a commercial building, use ofelectronic demand managers in assisting the utility in limiting the impacts of capacity shortage andconversion of blast furnace slag into a slow setting construction cement. Even though some of thesetechnologies are not linked directly to energy conservation or reduction of greenhouse gas emissionstheir application requires a level of innovation that can be applied to win-win technologies. An initia-tive by UNDP in 1996 sought to combine public and private sector efforts into a single project thatwould yield benefits for all. The concept of Public-Private-Partnerships achieved some milestones intechnology implementation even though the end result was not an operational entity with new tech-nology. The following is an example of how technologies can be introduced.

Box 1: Example of technology Intervention Through The Public Private Partnership Scheme

Opportunity: Industrial optimization in a local Park.The Willowvale Industrial Park is home to over 200 industrial and commercial entities. Their sizeranges from small printing enterprises to medium to large scale manufacturing plant with more than500 employees each.Problem: Energy use is putting a strain on the distribution network for electricity and reinforce-ments are constantly needed. Wastewater is being released into the sewer system in increasing vol-umes and since Harare recycles wastewater the levels of pollution are slowly rendering the munici-pal water supply less and less potable. Solid waste is not a major problem but opportunities exist forusing the solid waste produced as a source of energy.Solution: A team of consultants assessed the situation and recommended the introduction of a local(Park level) energy management entity. The entity would be a private company with the mandate tomanage the electricity supply to the Park on behalf of the various enterprises. The Energy ServicesCompany (ESCO) would negotiate tariffs, manage the distribution network and also consult on fac-tory level opportunities for improved performance.Benefits: The ESCO would be a profit making venture with shareholding from the companies in thePark and the public sector. The utility would save on network administration in the Park and alsodefer new investment. The individual factories would have access to local consulting services with afocus on the performance of the Park as an entity. The project would be the first of its kind in theregion with potential to attract new opportunities in other cities and in the region.

Framework for Implementation That Was Chosen:

Committee of Industry and Public Sector formed.Memorandum of Understanding signed for establishment of ESCO.Technology suppliers identified.Project Operator identified.Contracting process with Operator initiated

Project stalled on contribution of capital with the main reason being that the Operator had a differentvaluation of the business responsibility and that technology rights could not be signed over withouta clearer picture on the share of business that the ESCO would get. The project failed to get an arbitra-tor to assist in the negotiation between the parties and define the share of benefits and thereforestalled.

The above box gives an example of how barrier removal can be approached from an institutionalperspective. The project went a long way considering that it was bringing together partners who hadno previous experience in investing together. The limited administrative experience especially innegotiating the share of benefits that each partner would get contributed towards stagnation of theproject. In future cases this will be considered and partnerships between private and public sectorentities will not be recommended without special support.

Standards,Monitoring,Evaluation

TechnologySupplier

Loan

Standards

Subscriptions

Solar Water Heaters

Utility

RepaymentsRepayments

Repayments

FinancierTechnologyGrant

BuildingSociety

End Users

Specific Assessment

Solar Water Heaters for Urban HouseholdsThere are two ways of implementing this technology. One is to replace existing electric water heaterswith solar water heaters and the other is to displace new electric water heaters with solar waterheaters. The difference in the two cases is in the capital cost of the reference case. In both cases thebenefits accrue to the householder and the utility. Given the nature of the project and the need toinstall large numbers of units the following conditions have to exist for successful implementation:

• Utility program for implementation, with incentive scheme• Mechanism for end user financing• Supplier and installer of technology• Customer information programme• Market protection schemes - standards, guarantees and training

The above resources will partly mitigate the barriers that were identified earlier. Successful imple-mentation of the technology will however require the existence of a business institutional frameworkthat carries the responsibility to implement the business.

Fig 4.2: Framework for implementing solar water heaters

The following institutional structure is recommended. The arrows in fig 4.2 show the flow of infor-mation and technology as well as capital. What is not shown is the repayment of the capital which isa flow from the end user to the financier. All the flows account for technology buy down resultingfrom government or donor support. The participating business partners need a convincing basis foraccepting the project risk. Such a basis requires the generation of the following information.

• Confirmation of immediate market• Confirmation of cash flows• Inventory of available technology and suppliers• Negotiation of utility support

This information does not constitute a feasibility study but confirmation of current information andmobilization of a wide institutional support.

Benefit of Solar Water HeatersUse of solar water heaters has a direct linkage with electrical energy use in households. It is commonknowledge that investment in electricity production is a major cost for all countries especially devel-oping countries. In the case of Zimbabwe the need to use hard currencies for the acquisition of elec-tricity production plant as well as the required operation and maintenance provisions makes powerproduction a major burden to the economy. At present Zimbabwe imports about 45% of electricityrequirements and has not been able to fix a date for the next new power plant due to financial limita-tions.

Solar water heaters displace the demand for electricity and adds a new energy source to the energybalance of the country. Each heater displaces about 3kW of electrical demand and can double theenergy consumption of a household without adding to the demand on the grid. This is becausehouses without electric water heaters can start using more hot water and avoiding heating water onthe stove. Such households tend to rely partially on cold water for bathing which in itself limits thenumber of showers per day. Solar water heaters would therefore increase the good health practices ofthe poorer households.

The utility normal reduces the cost of household electrification by using the smallest size of conduc-tor for the distribution network. If solar water heaters are used the size of conductor can be furtherreduced thereby extending the reach of the allocated funds for electrification at any one instance.This would improve viability of the utility as it would reduce capital costs in an area where govern-ment policy normally restricts the tariff charged.

The environmental benefits of solar water heaters are linked to the reduction in use of coal for elec-tricity production. Zimbabwe has a coal dependent electricity sector with coal supplying about 60%of the electricity requirements of the country. At a regional level the imported electricity has a coalbased component from South Africa. This would mean an even greater benefit in terms emissionreduction than that stated above. Local environmental benefits would be in relation to coal mining.This is however limited by the fact that power station coal accounts for most of the overburden at thecoal mine hence it is a form of waste disposal. Without power production overburden would pile upto form mine dumps though at a lower rate than coal used in power generation. Spontaneous com-bustion is a problem with mine dumps at Hwange but these could be controlled by back-filling theoverburden into the mined areas.

As a new technology solar water heaters would naturally create employment and add to the energyinfrastructure possibilities of the country. There are at least 5 companies producing solar water heat-ers locally but more companies could result from a program to popularize solar water heaters.

Installation of Water Heater Time switchesThe installation of water heater time switches can be done under a similar program to the installationof solar water heaters. The difference is the lower risk as time switches involve a lower capital com-mitment and reversibility in the case of technology failure. Reversibility also increases the risk of enduser decommissioning of switches which would result in a higher failure rate. However the stepsrequired for implementation would be the same as for solar water heaters. The two technologies aremutually exclusive and would naturally compete for market. The framework differs from that for

SavedDemand

FinancierTechnologyGrant

Standards,Monitoring,Evaluation

ESCO

Loan

Standards

Subscriptions

Time Switches

End Users

Utility

RepaymentsRepayments

Repayments

water heaters in that the low capital requirement in time switches would not warrant the involve-ment of a building society. Also time switches are not considered a part of the building structure.An Energy Service Company, ESCO, would replace the installation company as is in the case of solarwater heaters. The ESCO would serve to install and monitor the performance of time switches. As away of encouraging continued operation the utility would pay for saved demand. This would offsetthe cost of the time switches to the end user. Reduction of demand leads to delay in new plant instal-lation which in turn leads to lower Long Run Marginal Cost of Electricity. In the current situation thiswould also lead to reduced import cost of electricity.

The standards and monitoring serve to protect the end user from malpractice by the equipmentsupplier. Lessons from the GEF PV Pilot Project are that once a new market is identified there will anincrease of suppliers of equipment some of whom the main objective is to make exorbitant profits. Inthe absence of controls there would be an ingress of low grade equipment which then discouragesnew users from buying the technology once experience is that there is great potential for failure.

Fig 4.3: Framework for Implementing Time Switches

Development Agency

The time switch as a technology is bound to be affected by human factors. When in use there is needfor human intervention. Reprogramming on change of habit or resetting of water temperature. Auto-mation and technology upgrading can reduce this but public awareness and training will be the mostappropriate solutions.

Benefit of The Use of Time Switches on GeysersThe basic impact of a time switch on a geyser is similar to that of a solar water heater except that atime switch achieves much lower levels of demand savings on electricity. In addition to reduction ofelectrical energy demand a time switch affords the household the opportunity to manage their de-mand. Similar principles could be used for water demand management. The time switch would beimported as a complete device but would require local skills to install and operate.

Environmental benefits would be linked to reduction in coal for electricity production as is the casewith solar water heaters.

Production of Ammonia from Coal Bed MethaneThis project relies entirely on the development of the methane industry in Zimbabwe. It is not possi-ble to assume that the establishment of the ammonia plant would be sufficient justification for thedevelopment of a methane production system. It is therefore not logical to carry out assessment ofthe necessary steps for project implementation without making the assumption that coal bed meth-ane will be supplied as part of a separate methane development program.

Underlying ConditionsThe apparent relocation of the ammonia plant would shift labour requirements and result in a majordisplacement or lay off of labour. Government intervention would not be excluded from this impacttherefore it is important to get public sector commitment to this project. The following basic datawould be required for this consultation.

• Quantification of capital requirements - an update of existing data.• Quantification of impacts - both commercial and social.• Confirmation of technology viability and availability.• Mobilisation of investor support.• Confirmation of company commitment

Even though the project would be a private sector investment, the social and economic impacts wouldattract and to some extent require government participation in terms of policy and technology buydown. The main product from the plant is fertilizer for agriculture and pricing is sensitive to socialcommitments. A byproduct of the plant is oxygen, which is currently piped to the steel plant nearby.It may not be critical that the oxygen supply stops but the steel process would shift in performance.Implications could be increased fuel consumption by the steel plant.

From the private sector or investor perspective the switch to coal bed methane might be the mostlogical step to make in the interest of long-term viability. However the capital requirements are noteasy to meet given the current economic environment. There is still an option to import ammonia,which may increase foreign currency expenditure but would make a competitive alternative to newinvestment.

It would displace other major investment but the added benefit of reduced electricity demand wouldbe an incentive. If other use for the gas is also developed the additional load provided by the ammo-nia plant would further justify the development of a gas industry which would bring further benefitsto the economy. Details of the case study are found in Annex????

Benefit of Using Coal bed Methane for Ammonia ProductionThe gas sector is to be a new sub-sector in Zimbabwe. Initiatives have just been started to draft thelegal framework for gas in Zimbabwe. It is hopped that once the legal framework is drafted there willbe a basis for private sector participation in developing the gas industry.

Sable Chemicals offers one of the major opportunities for use of gas in Zimbabwe. In the absence ofan initial demand for gas the gas infrastructure would not be developed without significant govern-ment funding. It is therefore important that Sable Chemicals remains committed to using coal bedmethane for ammonia production at their factory.

Substitution of coal bed methane in the ammonia production process will result in the release ofabout 84MW of electricity, which is currently used by the electrolysis plant. Given the situation withelectricity shortage any electricity that is released to the grid reduces the need for imports. In addi-tion once gas is available at the ammonia plant there will be the possibility that co-generation can beintroduced with the result that the plant may become a net exporter of electricity.

Gas is less carbon intensive than coal hence the replace of coal either as electricity or as a boilerfeedstock by coal bed methane will result in cleaner air. The ammonia production process using coalbed methane would release carbon dioxide unless the carbon dioxide is used to produce urea. Urea isalso a nitrogenous fertilizer and its production may displace ammonium nitrate with the result thatless coal bed methane is needed.

Methane leakage cannot be ignored but it is assumed that with modern technology these leaks willbe minimised.

Specific Assessments - Boiler Efficiency ImprovementBoiler efficiency improvement is only one of several measures that could be taken by industry toreduce energy use and impact on the environment. These measures have been analyzed and dis-cussed before. The logical step of implementing a win-win efficiency improvement project does notget implemented because of barriers that were mentioned earlier in table 4.2. In addition public sec-tor pressure for efficiency improvement in industry has not reached the optimum level for action.

Companies that are implementing efficiency improvement measures either have a high level of inter-nal skills that lobby management for these actions or have the equipment now impacting on produc-tion rates. Chibuku Breweries was studied under this project and has implemented the boiler effi-ciency improvement project that was identified. The option had been identified before this projectbut had not been implemented. Detail on this project has not been provided apparently because thecompany takes the information as confidential.

A boiler efficiency opportunity was also identified at Sable Chemicals. The project has not been im-plemented but signs are that the project will be implemented soon since the boilers are close to theend of their life. The major reason for delayed implementation is lack of capital. Given the analysis onbarrier given above it can be assumed that the benefits of efficiency improvement have not yet reachedthe threshold for action to be taken. Also boilers are used to supplement the steam supplied from thenitric acid plant hence they are not a primary device in terms of energy use.

Benefits of Boiler Efficiency ImprovementIndustrial boilers are the second major user of coal in Zimbabwe after power generation. Estimatesare that there are over 2000 industrial boilers in the country with the bulk of them being locally madeGreenock boilers. The sizes range from small units of 1 tonne steam per hour for the garment andfood industries to 20 tonne steam per hour units used in the larger manufacturing plant. Most indus-trial boilers are fired on washed coal fed through chain grates. In some cases automatic feeders areused for the larger boilers but it is common for the coal to be supplied to the inlet hopper manually.

In all cases there are no energy saving devices connected to the boiler. These would be:

• Flue gas heat recovery• Air preheaters• Soot blowers and• Electronic controllers

The price of coal has not provided the incentive for companies to install energy conservation equip-ment on boilers. It is also common to find operators with limited training running the steam plant.Even though coal prices have risen significantly retrofitting some of the technologies is no longerviable for reasons of:

• Technology incompatibility• Capital limitations• Lack of experience with the new technology• Low awareness and• Inadequate evaluation of benefits

Efficiency improvement is therefore done as part of plant replacement for reasons of operating costreduction other than just energy cost reduction. This is the case with Chibuku Breweries as well asSable Chemicals. The following benefits of boiler efficiency improvement have not sufficiently beenpublicised to attract the attention of key stakeholders.

• Reduction in airborne pollutants from coal combustion• Reduction of landfill disposal of coal ash• Reduction of coal demand and burden on coal transport• Improvement of boiler house working environment• Reduction in operating cost of boiler plant

The impact of one boiler may not be felt by a larger population but the impact of improvements atseveral locations will be significant. Boiler efficiency improvement has been identified as a majorgreenhouse gas emission reduction opportunity in Zimbabwe.

Co-generation at Hippo Valley Sugar EstatesThis opportunity was identified with the help of the company. It has been reported that the companywill now invest in the co-generation plant. The company would however like to install environmentmanagement equipment on the boilers but would need financial support for this action. Given thatthe plant will be burning bagasse and that it will not be interconnected to the grid it is not clear whatthe impact on greenhouse gas emissions will be.

In the absence of site-specific data it is difficult to analyse this option further. However co-generationadds to the energy sources in the country and reduces the dependents on centralized coal fired plant.

Zimbabwe has experience with bagasse based co-generation at the Triangle Sugar Mill. The differ-ence now would be improvement in technology, which has been in discussion with Triangle. If thetechnology at Hippo Valley can demonstrate the benefits of more efficient technologies it would bemuch easier to evaluate the possibility of upgrading the technology at Triangle. A study has been

carried out in East Africa on the potential for improving co-generation in the sugar mills. This infor-mation would be relevant for this study and in the absence of more specific information the EastAfrican experience can be used for reference.

Co-generation of electricity in this case has two driving forces. The first one is the need to supplyelectricity to the sugar mill and the second one is the electrification of the surrounding areas. Thetreatment of the project would be different if the electricity was only for in plant use. The study onEast Africa shows that in most cases a combination of sugar production practices, processing and co-generation efficiency can yield sufficient electricity to allow delivery to the grid. The following figureillustrates this point.

Fig 4.4: Generic model for Surplus Electricity Production in Sugar Factory

In general the sugar mill produces excess electricity. In some cases the sugar variety is selected tohave high fibre content. All this is dependent on the price of electricity and the price of sugar. Thefollowing table is an example of the parameters for a sugar mill in East Africa.

Table 4.3: Example Sugar Co-generation from East Africa

Cane Crushing Capacity 280 TCH

Annual Area Harvested 21000 Ha

Sugar Cane Yield 98 Ton/ha

Bagasse Percentage in Cane 40 %

Bagasse Moisture 50 %

Net Calorific Value of bagasse 7493 KJ/kg

Specific Steam Consumption of Sugar Mill .5 ton steam/ton cane

Steam to Bagasse Ratio 2.2 ton steam/ton bagasse

Excess bagasse 332086 ton/year

Surplus electricity potential 79 kWh/ton cane

Annual electricity production 163 GWh

Surplus power capacity 22 MW

Estimated power availability 10 Months

Source: CFC - Technical paper #12These figures can be used to determine estimates for Hippo Valley..

Co-generation Plant

Sugar Milling andProcessing

Electricity Grid

Factory

SugarMolasses

BagasseSteam

Cane

Benefit of Sugar Co-generationThe electricity supply system in Zimbabwe is dominated by coal. The sector is also starved on capitalsuch that the next project has been deferred for the past eight to ten years. 45% of electricity con-sumed in the country is now imported from RSA, DRC and Mozambique.

Most of the power is generated along the Zambezi River by the Kariba hydroelectric plant and theHwange coal fired plant. Most of the power is used in Bulawayo and Harare with commercial farmsand Estates as well as mines providing the major loads in rural areas. Hippo Valley Estates are in theSouth Eastern parts of the country. This is away from the existing electricity generation plant. Addi-tion of any generating facilities in the area will improve system performance by reducing losses andimproving power quality. In addition to increasing the internal electricity generating capacity co-generation at Hippo valley will also increase the local contribution to the energy balance.

Reduction of dependence on coal for electricity production results in the reduction of carbon inten-sity of the energy sector in Zimbabwe. Sugar cane bagasse is a renewable energy and apart from theenvironmental impacts of sugar production it has minimal impact on the environment. The reduc-tion in carbon intensity does not necessarily mean a reduction in energy demand met by coal butavoidance of some of the new emissions, as the electricity sector in Zimbabwe will continue to grow.

The electricity sector has always expressed concern over the reliance on hydroelectricity. Frequentdroughts have had a toll on the supply of electricity and utilities in the region have reviewed theirplanning criteria for hydroelectricity. Sugar bagasse offers a non-coal alternative with the possibilityof converting to coal during extreme drought conditions. Sugar is dependent on irrigation thereforedroughts will also affect fuel availability for the co-generation plant. This may appear climate insen-sitive but power cuts result in a higher demand for fossil fuels as well as fuel wood. The provision ofa facility that can operate on sugar cane bagasse under normal circumstances and on coal duringtimes of drought introduces flexibility into the grid that minimizes emission of greenhouse gases.

Development of a co-generation plant at Hippo Valley will obviously generate new employment.

Other Opportunities for Technology Improvement.In addition to the technologies selected by the stakeholder meeting there are other promising tech-nologies that can be considered for Zimbabwe. The following is a discussion of some of them.

Co-generation at Bindura Smelting and Refining CompanyBindura Smelting and Refining Company has a steam boiler rated for 25 tonne steam per hour. Theproposal is to use this boiler to drive a back pressure turbine. The exhaust steam from the turbine willthen be used for the plant process. The boiler is coal fired and the fuel for the co-generation processwill be retained as coal. The plant will there reduce demand for electricity from the grid. The com-bined efficiency of the co-generation process can be as 88.7% compared to 80% for the boiler effi-ciency and 25% for the electricity production process. The improved performance will reduce theenergy bill for the company and reduce the capital burden for the utility. The capital requirement aswell as the skills for operating the new technology may not be resident in BSR. This would increaseemployment at the refinery but also increase the spread for the technical staff at the plant. Given thegeneral trends by industry to reduce the spread of activities and to concentrate on core activities, thecompany may wish to either defer investment or sub-contract the power production project.

This opportunity requires further investigation, as BSR would need to be consulted on their views.The issues of barriers and introduction of non-core activities in the plant would need clarificationbefore the opportunity can be realised. In addition the cost of the proposed investment needs to beinvestigated.

Apparent Criteria for Cleaner Technology Investment

Previous studies have shown that viable cleaner technology retrofits require a very wide improve-ment margin before they are implemented. The basis is not only financial benefit but also other crite-ria emanating from the economic environment. It is apparent that a difficult environment shortensthe planning horizon to the extent that companies are looking at achieving even less than a year’sproduction. Given such conditions performance improvement is limited to maintenance of existingplant and other very short-term measure. In the case where new investment is being made the deci-sion to accept more efficient technology is much more readily accepted. This is confirmed by the factthat the sugar mill would be keen to install cleaner technology since the decision to install the co-generation plant has been made. The brewery is also replacing boilers on the basis of energy conser-vation since the old boilers are threatening production and competitiveness. Another example fromoutside this study is that a textile company reduced energy consumption by refurbishing and up-grading the plant as a way of improving export competitiveness. Energy savings were then factoredinto the analysis even though in most cases energy savings do not justify equipment upgrading. Thisis not because the energy savings are not enough to compensate for capital as shown by the incre-mental cost curve shown below. The low cost or negative cost measures remain un-done even thoughthe analysis demonstrates financial viability.

Fig 4.5: Example Win-Win technologies Still to be implemented

Reduction Ton CO2

-40

-30

-20

-10

0

10

1

2 3

4

520

-100000 100000 300000 500000 700000 900000

The following cleaner Technology options could be explored:1. Ammonia from Coal bed CH42. Mini hydro3. Boiler Efficiency Improvement4. Efficient Tobacco barns5. Electricity from Sewage Gas

The above situation could be solved by legislation since there would be no additional net cost for thecompanies to comply with the legislation. However the environmental legislation that could haveachieved these benefits is taking a long administrative route before enactment. On the other handlegislation that could be applied currently is not enforced. Even though several institutional issuescould be used to explain this situation the primary reason is lack of commitment to the technologybenefits. If government was committed to performance improvement through the identified meas-ures with a background of recognized benefits steps would have been applied to get companies toimplement the measures. It is also not fair to base the lack of implementation of the opportunities onlack of commitment as other factors point to competing demands especially regarding provision ofbasic industrial and energy sector capital. Even though the projects have not been implemented mostof the work done so far was based on government initiative and private sector co-operation.

Conclusions

Zimbabwe has a high potential for the installation and use of cleaner technologies with win-winbenefits. Despite several studies having been carried out there are major impediments to the immedi-ate implementation of these technologies. The barriers can be classified as follows.

Financial BarriersThe cost of technology is not necessarily the reason for slow adoption of cleaner technologies. Com-panies seem to be focused on other pressing issues such that there is absence of motivation to concen-trate on optimisation of activities including installation of technology for cleaner production reasons.Companies have implemented other technologies which may be more demanding than what wasdiscussed in this report hence ability to present bankable projects is not necessarily the reason either.

Awareness of Cleaner TechnologiesIn cases where companies have installed new technologies they have not considered additional com-ponents that could have achieved cleaner performance with lower cost. This includes the turbineinstalled at Hypo Valley where higher pressure steam would have increased the volume of powerproduced and the new pumps installed at Bulawayo pumping stations where upgraded controlscould have allowed for optimum pump sizing as opposed to the traditional 10% over sizing. This ina way points at lack of up to date information on technology improvements.

Limited Technology Assessment SkillsMotivation to upgrade technology is often a result of resident skills to assess the benefits and presenta convincing story to the decision makers. Climate change is not so high on the corporate agendahence technical staff in industry do not spend time looking for climate friendly opportunities. As aresult skills are not developed and technology assessment for environment protection is not used asa criteria for investment.

The above are amongst other barriers that appear to limit the adoption of win-win technologies inZimbabwean industry. As a result policy change, awareness building and energy pricing taken inisolation cannot achieve the desired results of cleaner technology. There is a need to implement anintegrated program for barrier removal that would see accelerated technology upgrading in indus-try. The program could start by pursuing those options that are more promising it terms of financialand economic benefits as well as a wider market for application. The steps for implementing theprogram could include;

• Discussion with project owners to confirm interest and capacity needs.• Discussion with interested financing agencies to determine criteria for funding.• Technology assessments to confirm appropriate solutions.• Documentation of case studies from other countries.• Review of government policy for supporting private sector entities.• Development of a framework for bankable project documents for the energy sector.

The above steps could apply to other technology improvement projects.