034ca-EECA---Solar-in-NZ-May-2001 (1)

8/10/2019 034ca-EECA---Solar-in-NZ-May-2001 (1)

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SOLAR ENERGY USE AND POTENTIAL IN

NEW ZEALAND

Energy Efficiency and Conservaion A!"oriy

PO #o$ %&& ' We((ingon

)ay *++,


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Acknowledgments

A number of people have made valuable contributions to the preparation of thispublication. EECA would especially like to acknowledge Industrial Research Ltd,

who prepared the initial version of this report.

he report was pro!ect managed by Erin Roughton, EECA who can be contacted [email protected] if you would like further information about any contentsin the report.

All material in this report can be reproduced with due acknowledgment of EECA."owever, while every care has been taken to ensure that the report contents, andinterpretations thereof, are as accurate as possible, neither EECA nor the authorsaccept any liability for loss or damage occurring as a conse#uence of reliance on anyinformation and$or analysis contained in this publication.

EECA %ay &''(


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Ta-(e of Conens.

E)ecutive *ummary+

(. *olar Resource

(.( he rimary Energy *ource(.& Insolation arameters(.- Insolation for *everal *ites in ew /ealand.(.0 Comparison with Australia, and Europe.

&. *olar Energy Conversion echnologies

&.( *olar hermal Conversion&.(.( Low emperature 1lat late *ystems&.(.& %id emperature 1lat lates and Evacuated ubes including Low

Concentration.&.(.- "igh emperature *ystems

&.& *olar hotovoltaic Conversion+&.&.( echnological Aspects&.&.& Recent Industry rends&.&.- Economics and Applications of 2 Electricity

-. resent and otential enetration in ew /ealand

-.( *olar hermal Conversion-.& *olar 2 Electricity

0. Environmental and *ocial Advantages

3. 4arriers to 5ptake of *olar Energy *ystems

3.( echnical 4arriers3.& Cost 4arriers3.- %arket 6rganisational 4arriers


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NEW ZEALAND

Execut!e summ"#$

Int#oducton

*olar energy is the most abundant, practically ine)haustible primary energy availablein ew /ealand.

It is a resource of immense potential. echnologies are available at present to convertthis resource to heat in a cost competitive manner, and to electricity at a cost suitablefor small niche markets. his resource has the technical potential to supply all presentand foreseeable residential energy needs and contribute substantially to commercial

and industrial re#uirements as well.

*olar energy would help ew /ealand diversify its present energy sources and togrow its e)isting manufacturing base.

o achieve this potential, new initiatives would be re#uired to help overcome the costand market barriers facing these modern and continually improving technologies.

%u##ent stu"ton "nd &otent"l cont#'uton

Sol"# (ot w"te#technologies currently contribute more than 0'78h 9'.(: of ew/ealand electricity consumption; electricity e#uivalent per year. hey are costeffective in a number of applications at


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8hen the cost of 2 electricity approaches (3=(


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Solar thermal conversion systemsare the oldest, most advanced and most economicalsolar conversion systems yet developed. hese are in use in ew /ealand

resently available flat plate systems 9unglaBed or glaBed collectors; are most

often limited to operating temperatures below >'C in order to maintain a

relatively high conversion efficiency. his makes them useful for solar swimmingpool heating 9-'C; and solar domestic hot water applications. hese two areas

have been the main applications in ew /ealand.

Recent advances in the performance of selective surfaces for solar energy

conversion have led to recent industrial production of high performance selectivesurfaces with high solar absorbency and very low thermal emittance. his enables

these surfaces to reach temperatures of -''C and above. Application of this

technology is at the demonstration stage at several European pro!ects. *o far, noapplication of these systems has been undertaken in ew /ealand even though

some evacuated tubes of this type are available here.

*olar hermal Electric power plants are the only large=scale commercial solar

electricity generation technology implemented to date, but not in ew /ealand.

he solar thermal technologies that seem most appropriate for ew /ealandDs

insolation values are low and mid temperature systems collecting globalirradiance. 8hile in relatively common use for domestic water heating,commercial or industrial scale collectors have so far not been widely adopted,despite recent advances and technical feasibility.

A large number of installations have been retrofits to e)isting homes. 1rom an

economic standpoint, such installations do not benefit from savings in theconstruction costs that new installations would occasion. onetheless, at anaverage cost of around 0''' for a full installation in a residential home, thesesystems are e)pected to save significant #uantities of electricity, depending onlocation

*olar domestic hot water is cost competitive with retail electricity tariffs

throughout ew /ealand and that the ma)imum yearly output from this source isonly limited by the number of systems that can be installed.

A most promising trend in thePV (photovoltaic) industry worldwide has been theinvolvement of all ma!or petroleum companies in the ownership, direct productionand promotion of solar energy, especially photovoltaic electricity production. hisinvolvement has resulted in new, larger scale 2 production plants in Australia,Europe and 5*A that may realise substantial economies of scale.

he possible markets for 2 systems are also very diverse, often with #uite differentand opposing re#uirements. he main applications can be divided into four broadsectors, namely consumer products, industry applications, remote area supply, andgrid connected systems 9two distinct types;.


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Consumer products 9calculators, watches, toys;, individual power supplies

9holiday homes, caravans, mobile homes, boats;, and individual supplies fornovelty products 9home security, garden lighting, car sunroofs, fans, and

battery chargers; provided the first market for 2.

here are a number of applications where 2 systems are sold to a serviceindustry, which then uses these for its own purposes, in its products orservices. 1oremost in this area are Fprofessional systemsG provided bycompanies active in the communication industry and the cathodic protectionindustry. ew /ealandDs electric fence industry is also a substantial and goode)ample in this category of applications.

*tandalone power system applications include small to medium scale 2

technology, ranging between hundreds of watts and a few kilowatts, to supplyservices in regions away from the main distribution grid. his is thought to bea pivotal growth area for the 2 industry in the coming decade in both

industrialised and developing countries. he range of services includes waterpumping, water treatment, electric supply for small industry, domestic,medical and institutional uses 9houses, schools, clinics, small shops, farms;and communication links, both local and long distance via telephone,television and radio.

7rid connected distributed supply system applications are a newer but

vigorously growing e)ample of 2 use in the urban environment. hese aresimple and only re#uire 2 panels and inverter to provide AC voltage andconnect to the local distribution grid. hese systems provide electricity at the

consumer end of the distribution chain and hence compete with the retail priceof electricity

7rid connected power plant applications have been trialed overseas and

include both full scale central 2 stations feeding power to the distributiongrid, and embedded generation 2 systems used to correct either overloads ordegraded power #uality at critical points.

In ew /ealand, commercial e)amples of all the above applications, e)ceptcentralised and embedded power systems, can be found. he largest applicationsinclude isolated telecommunication and weather monitoring sites, for marine safety

devices along the coast of ew /ealand, and for electric fences and navigation lights,both these last products being also e)ported overseas. here are numerousapplications of 2 as battery chargers for caravans, holiday homes and boats.

he main impediment to further uptake of 2 technology has been its cost comparedto grid electricity prices, which is e)tremely well distributed throughout ew /ealand.

En!#onment"l "nd soc"l "d!"nt"ges o, usng sol"# ene#g$

*olar technologies provide sustainable energy. 4oth solar thermal and photovoltaic92; technologies are modular in nature and are therefore adaptable to a variety of

applications varying in siBe, output temperatures and other operating re#uirements.


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Although capital intensive in the case of 2, solar technologies rely on a freelyavailable source and have e)tremely low maintenance costs. 2 is the energy sourceof choice for navigation lights, telecom sites and isolated or remote areas, includingAntarctica where reliability and low maintenance are of utmost importance.

he lifetime of both solar thermal and solar 2 technologies are greater than &3 years.*olar 2 modules carry a minimum manufacturer guarantee of &' years longer thanmost power plants, conventional or new.

*olar technologies are easily integrated into new or e)isting buildings they areunobtrusive, can enhance the aesthetics and architectural appeal of buildings and areoften considered a positive asset due to their green image.

4oth technologies still show a large potential for cost reduction in the near future dueto technological advances and increased production based on substantial markete)pansion.

-"##e#s to t(e "do&ton o, sol"# ene#g$ s$stems

here are several barriers to the uptake of solar conversion systems in ew /ealandand indeed elsewhere. %ost are manifest in the implementation of new technologiesthat attempt to displace e)isting, well=established technologies. As such they relatedirectly to the dissemination of solar thermal and solar 2.

hese barriers may be seen as a reflection of the way technological progress has acertain momentum, and tends to remain oriented in certain directions. his inertia hasas a direct conse#uence the e)clusion of newer, possibly more appropriate technical

solutions as either not mature enough, not cost effective or not worth pursuing.

his e)clusion can take the form of technical barriers, cost barriers and$or marketorganisational 9or structural; barriers. In the case of solar, these latter two barrierse)ist for all technologies while the former is relevant to a greater e)tent for 2 thanfor solar thermal.

1or the solar thermal industry, technical barriers have been mostly resolved, at leastfor low temperature conversion. *ystems have e)isted for some time now withsufficiently high efficiency at low cost to yield a very positive return over theirlifetime. he systems will cost substantially less than the cost of electricity needed to

produce the same output.

he main cost barrier to the dissemination of solar technologies is ostensibly theirtotal cost 9and hence initial capital investment; to the users compared to alternativesupply. "ere again, for solar thermal systems this cost is lower over the lifetime of thesystem than for 2s.

1urther, the building industryDs traditional conservatism, 9and that of associated tradesand professions= builders, carpenters, plumbers, architects; their lack of awareness,understanding and e)perience of these technologies constitute a ma!or barrier toadoption of solar technologies.


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*olar technologies, which are typical of many renewable energy systems, are oftencapital intensive and have relatively low ongoing and maintenance costs. Economicmeans of analysis that would be advantageous to solar technologies would incorporatesome assessment of reliability, low maintenance and nil fuel costs. 1or e)amplelifecycle costs would be more appropriate than a traditional payback period analysis.

here is also in ew /ealand an inability to capture the benefits of solar technologyby users. *olar is not widely recognised to add value to the price of a house and is notsufficiently valued at national and regional levels or in regulations and standards.

he organisational structure of the residential and commercial building industryengenders conflicting interests for investors and users

."#kets ,o# sol"# ene#g$

he main immediate markets for solar energy technologies in ew /ealand are theresidential and commercial building industries 9and by implication the electricity

industry as a whole generators, lines and retail companies;. hese markets are by farthe most appropriate for solar technologies as they deal in space heating, waterheating and electricity.

*olar technologies are eminently suited to providing these re#uirements by on=sitegeneration in competition with centralised generation and e)tensive distribution lines.


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NEW ZEALAND

(. Sol"# #esou#ce/

(.( T(e m"#$ ene#g$ sou#ce+

*olar energy is distributed right across the country, re#uiring neither transportationnor any special infrastructure for its use.

he sun provides the earth with a long=term supply of high #uality energy at anoverall rate nearly (',''' times mankindDs present use. his supply reaches ama)imum intensity of more than ('''8$m& at the earthDs surface, sufficient forconversion to other forms such as heat, electricity and combustible materials.

er year, the ew /ealand land mass 9&>


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through clouds, gases and particulates. irect irradiance is the power directly from the sun.It is high on a clear summer day, low or near Bero on cloudy summer or winter days when thesun is occluded by clouds and gases. iffuse irradiance represents the power reaching theearth after being scattered in the atmosphere. It is the reason we can Fsee in the shadeG."ence these three parameters are seen to be related.

6n a more practical level, they each represent the power various practical solar conversionsystems are likely to receive at any one time. A flat plate solar collector will receive anamount of power related to the global irradiance, a south facing window 9in the southernhemisphere; will receive mostly diffuse radiation while a two a)is sun tracking solarcollector or heliostat will receive an amount related to the direct irradiance. In this conte)t,highly concentrating systems which, because of their optics can only FseeG a small angle ofthe sky, are by necessity, two=a)is tracking systems following the sun. hese can only use thedirect irradiance from the sunDs beam. *uch systems are most useful when the directirradiance is very high, when clear sky conditions predominate.

012 Insol"ton ,o# se!e#"l stes n New Ze"l"nd1

he calculated values of total daily global energy and total yearly available energycan indicate the Fsolar #ualityG of a site.

he global, direct and diffuse irradiances vary as functions of time of day, day of year,and from year to year. 1or a given site, ypical Reference Jears 9RJ; are produced.hey represent ' hourly e)pected values for global, direct and diffuse irradiances.

*uch values are available for a number of sites in ew /ealand 9Kaitaia, Auckland,8ellington, Christchurch, Invercargill;. hey can be successfully used to calculate thee)pected output from a variety of solar conversion systems at those sites on an hourly,daily and yearly basis. hese RJ can also be used to calculate total daily energye)pected on a horiBontal surface and total daily energy in the direct sun beam. RJcan also be used to calculate the total yearly solar energy available to solar conversionsystems.

013 %om&"#son wt( Aust#"l"4 "nd Eu#o&e1

wo regions of the world are at the forefront of implementation of solar technologies

are Australia and the European Community, especially 7ermany. In order tounderstand the potential of solar energy in these three regions, it is possible tocompare global irradiances in ew /ealand, Australia and 7ermany.

he first comparison, presented in 1igures ( and &, is that of the total daily globalenergy received on a horiBontal surface in Kaitaia, araparaumu and Invercargillcompared with the same #uantities in *ydney and %elbourne.

It is clear the values of daily energy are similar for all sites. he ma)imum values areabout -'%@$m&per day in @anuary decreasing to a ma)imum value in winter of abouteight to (&%@$m&per day for all sites. Invercargill, the lowest valued ew /ealand

site shows lower daily values 9of about (3 percent through the year; indicative of itssouthernmost position.


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All other sites are only slightly lower than Australian sites. *ites in ew /ealandsuch as elson, 4lenheim, 7isborne and "awkes 4ay, with the highest ew /ealandvalues are e)pected to have comparable or higher values than %elbourne;.

7lobal energy has ma)imum daily values that are high for day one in summersummer, low for day (?', mid winter and again high around day -0', in summer.

his roughly sinusoidal variation in the ma)imum possible irradiance illustrates theseasonal variability of the resource. 6n top of this there is, intermittently throughoutthe days of the year, occurrence of values below these ma)imum values. hese are anindication of intermittent sunshine or cloudiness and are relatively e#ually scattered inthe ew /ealand and Australian data.


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/ig!re *. )on"(y averaged dai(y g(o-a( irradiance a severa( sies in Ne0 Zea(and23a(!es for )e(-o!rne ca(c!(aed fro4 "e a-ove fig!re are inc(!ded for co41arison

A second comparison of total yearly energy available per s#uare meter is shown in

table ( for each site and for a typical site in 7ermany 93& north;. his value, the sumof all daily values throughout a year, incorporates the effects of the ma)imum valuesof irradiance possible, due mostly to the latitude of the site. It also includes the actualatmospheric conditions 9clearness, particulates, water content in the atmosphere andcloud conditions; into one F#ualityG parameter.


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Ta-(e ,. Ty1ica( va(!es of oa( year(y g(o-a( energy 1er s5!are 4eer for severa( siesin A!sra(ia6 Ne0 Zea(and and E!ro1e2 T0o !nis "ave -een !sed2 7,8W" 9 %2: );(3'.- (?'7isborne 3-'.' (''&.3

Again, the availability of solar energy at ma!or ew /ealand sites, at about (0''=(3''k8h$m&per year on a horiBontal surface, is seen to be at least comparable to%elbourneDs and certainly much higher than at European sites.

*ydney, at around (?'' k8h$m&of global sunshine a year is considered a very goodsite for a variety of solar energy technologies including concentrating systems. *iteswith (0'' to (3'' k8h$m&a year are considered to also be #uite good prospects forsolar technologies, especially those technologies, such as flat plate collectors, that use

the global component.

In Europe, where indigenous energy sources are scarce or e)pensive, sites with('''k8h$m&are seen as potential candidates for several solar technologies.

%ost solar collection systems are tilted towards the e#uator, enabling them to collectsubstantially more than the horiBontal values above. 1or e)ample, in 8ellington a flat

plate facing orthward and tilted at around -3from the horiBontal, would increase its

yearly solar energy collection by about (3 percent or over (>3'k8h$m&per year.


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&. Sol"# ene#g$ con!e#son tec(nologes/

510 Sol"# t(e#m"l con!e#son/

*olar thermal conversion systems are the oldest, most advanced and most economicalsolar conversion systems yet developed. hey invariably consist of a mechanism forcapture of solar energy, its conversion to heat at a range of temperatures and its useeither directly or in the production of electricity or chemicals using heat.

he main differences between the various solar thermal technology types relate to the

temperatures achieved. *ystems are available for production of low temperatures 9-'

to >'C; medium temperatures 9


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surface is sometimes coated with a solar selective film to suppress thermal reradiationat the higher than ambient operating temperatures. he construction of the collectingsurface can be large flat plates with fluid tubes attached 9tube=on=sheet collector;, aseries of parallel finned metal tubes 9channels for the fluid; or integral glass tubeswith fin and metal tube inside them, all connected to a header. A simple e)ample of a

flat plate collector is shown in figure -.

6perating temperatures of these systems range from ambient to about (&'C and

typically follow a close to linear solar to heat conversion efficiency curve 9see figure0 below;.

he conversion efficiency decreases rapidly as the operating temperature is raisedabove the ambient for a given solar irradiance. "ence in the e)ample illustrated in

figure 0, raising the working fluid temperature by &'C can be achieved with a typical

efficiency of >'=?' percent whereas to raise its temperature by 3' C can only be done

with an efficiency of 0' percent, and reaching higher temperatures implies anefficiency close to Bero. /ero efficiency, or e#uivalently a Bero fluid draw off occurs

at the so=called stagnation temperature 9


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Although the technologies used in the flat plate type solar collector systems arerelatively old, incremental improvements have occurred over most of the last (' yearsin two main directions. 6ne has led to lower costs, the other to higher system

performance. In the latter case, the two main limitations in the performance of theabove systems are related to the optical properties of the absorbing surfaces used

9selective and non=selective; and to the relatively siBeable heat loss by convectionoccurring in the collectors.

A typical indication of the application of these systems in ew /ealand, a residentialsolar hot water installation may include a 0m&solar collector area, an ade#uately siBedstorage cylinder 9&?' litres; with au)iliary booster 9gas or electric;, providing hot

water at around >'C all year round.

*uch a system will provide between 3' and ?' percent of hot water needs and displace&.& to &.3 %8h of electricity use per year.

epending on siBe, type and configuration, this solar hot water system includingcylinder would cost between /-,3'' and /3,3'' fully installed.

&.(.& %id emperature flat plates and evacuated tubes including low concentration.

Recent advances in the performance of selective surfaces for solar energy conversionhave led to new industrial production of high performance selective surfaces withhigh solar absorptance and very low thermal emittance. his enables these surfaces to

reach temperatures of -''C and above. 8hen these characteristics are combined

with reduced convection losses, the performance of a solar collector follows asubstantially improved efficiency curve. his is shown in figure 3.

1or these surfaces, not only is the stagnation temperature substantially higher but alsothe efficiency curve is a strong parabolic rather than linear function of temperaturedifference. hus the efficiency remains high over a relatively large range oftemperature difference. In figure 3, the efficiency is above >' percent for temperature

differences greater than (''to (3'C. *ystems with these characteristics are capable

of operationally producing water at (''C, steam at higher temperature or, with small

concentration, operating at temperatures of (


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5 0 7 0 0 1 0 0 7 0 0 1 5 0 7 0 0 2 0 0 7 0 0 2 5 0 7 0 0 3 0 0 7 0 0 3 5 0 7 0 0

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/ig!re ?. Poenia( of so4e se(ecive s!rfaces 0"en convecion (osses are s!11ressed

hese surfaces are presently industrially produced on evacuated tubes and may soonbe applied to flat plate technology as well. In the case of evacuated tubes, the vacuumensures very good convection suppression. his convection suppression is essentialto achieve the potential of these surfaces and reach ma)imum performance. "owever,even flat plate collectors incorporating minimal convection suppression mechanismshave been shown to produce steam with relatively high efficiency.

Also being developed both here and overseas are flat plate based collectors

incorporating low solar concentration 9up to two sun;. In this case, the concentrator isa non=imaging type which still has a wide angle of view and able to collect most ofthe global irradiance falling on it. hese systems are then e)pected to be capable ofhigher performances in ew /ealand conditions.

hese developments are opening up a new set of applications for solar thermalconversion operation at mid temperatures. hese include commercial and industrialhot water supplies for food processing and the dairy industry, heat for sterilisation at

around


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scale systems in ew /ealand. "owever their uptake has not been high, nor has itspread to the applications mentioned above, possibly due to their lower efficiencies athigher temperatures, the re#uirement for large areas for solar collection, and theavailability of more traditional, fuel and boiler based systems.

&.(.- "igh emperature *ystems

Collector systems using selectively coated tubes at the line focus of parabolic troughreflectors are among the oldest high temperature solar technologies developed. In atypical power plant application, reflectors with concentrations of 0' suns or more heat

a fluid travelling through tubes to temperatures of -3' to -'C. his fluid is then

used to raise steam for a conventional steam turbine generator. hese *olar hermalElectric 9*E; power plants are the only large=scale commercial solar electricitygeneration technology implemented worldwide.

*E power plants are operational in the %o!ave esert in California generating3'%8. An interesting variant of these linear focus collector fields has been

proposed as a steam preheating stage for the *tanwell coal fired power station innorthern *8.

Jet other solar collector systems have full parabolic dish reflectors or a heliostat fieldwhich track the sun in two a)es to produce a point focus image reachingconcentrations between (''*un and &'''*un. At the point focus a receiver or reactor

can reach temperatures of ?''C to &'''C, thus providing steam, electricity or

sufficient heat for chemical reactions.

In general it is estimated that electricity costs from *E plant are of the order of('c$k8h or less in areas where the direct beam irradiance reaches appro)imately&'''k8$m&per year.

All these high temperature plantsD outputs depend critically on the long=termavailability of direct solar radiation. hus they are not likely to have a high output in

ew /ealandDs relatively variable irradiance conditions. Conse#uently they areunlikely to be economically viable even when capital costs are reduced.

Summ"#$ o, sol"# t(e#m"l s$stemsIn summary, the solar thermal technologies that seem most appropriate for ew/ealandDs insolation values are low and mid temperature systems that collect globalirradiance.

he widest applications to date have been low temperature unglaBed flat platecollectors providing swimming pool heating and low temperature glaBed collectors

providing domestic solar hot water. Commercial or industrial scale collectors have sofar not been widely adopted, despite recent advances and technical feasibility.

*ince pioneering days of the (?'s, when ew /ealand had a siBeable initial uptake

of solar thermal technologies, a local industry has been established with over elevenmanufacturers and importers marketing a variety of mostly local collector systems.


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his industry has e)perienced a (' percent per year growth over the last three years,due in part to greater public awareness and in part to coordinated schemes andinitiatives such as EECADs Energy *aver 1und.

%ost o, sol"# (ot w"te# ene#g$

A large number of installations have been retrofits to e)isting homes. 1rom aneconomic standpoint, such installations do not benefit from savings in theconstruction costs that new installations would occasion. onetheless, at an averagecost of /0''' for a full installation in a residential home, these systems aree)pected to save between &0''k8h and -(''k8h electricity per installation per year,depending on location.

heir economic viability can be calculated two ways. he first is using the principleof Mpayback periodD, which is usually between seven and (& years, depending on thedisplaced electricity costs. he second is on the principle of Flifecycle costG, the costof installing a solar system over its lifetime, compared to the cost of electricity paid

during that same period.

In the latter case, and for every solar system, a substantial net saving can be shown,which is e#uivalent to eight to (0 years of displaced electricity or gas supply.E#uivalently, the cost of producing a k8h may be calculated for systems installed in

ew /ealandDs ma!or population centres. his results in costs of eight to (& cents perk8h over a realistic &' years lifetime of the system.

It is interesting to speculate on the economics of residential solar thermal systems ifconstruction companies or builders of new homes offered them as an option. *incemany solar systems are built into the roof structure rather than being placed proud ofthe roof. In this eventuality, a larger market would almost certainly grow, enablingsubstantial economies of scale and subse#uent reduced production and installationcosts. *uch trends are appearing already, with some national construction companiesand architects investigating options for incorporating these technologies in theirstandard designs.

515 Sol"# &(oto!olt"c con!e#son/

&.&.( echnological aspects+

irect solar to electricity conversion can be carried out with hotovoltaic 92; cells.hese cells are made from a variety of semiconducting materials either in singlecrystal form 9silicon, gallium arsenide 97aAs;, indium phosphide;, in multicrystallineand polycrystalline form 9silicon, cadmium telluride=Cde, copper indium gallium di=selenide CI7* etc; or in amorphous form 9silicon, silicon=germanium alloys;. In eachcase, laboratory cell production and the corresponding industrial scale productiontechni#ues are different and lead to different performance parameters and solarconversion efficiencies.

6f all the above materials and variety of cell designs possible, only a small numberhave reached industrial production. *ome, such as crystalline 7aAs, have been shown


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to be capable of the highest conversion efficiency of all single !unction 2 devices9-3 percent;, yet have only found a small volume market in space applications due totheir cost of production.

At the present time most industrially produced 2 cells are silicon based as silicon

technology is the most advanced and has benefited from the several decades ofe)pertise of the microelectronics and computer industries. Efficiencies of laboratory

produced cells 9&0.3 percent; are far in advance of those for industrially producedcells 9(3 percent;, reflecting the different methods used in their manufacture.

evertheless, several laboratory technologies are already, or are being, transferred toindustry 9eg laser grooved buried contact patterning; with conse#uent efficiency gainsand$or reduced cost. Recently, methods for producing single crystal siliconspecifically for the solar cell market, and hence at reduced wafer cost, have beendeveloped in collaboration with industry 9eg. he Epilift techni#ue at the Australian

ational 5niversity; and are likely to be commercial realities soon.

In a similar trend, high efficiency, high cost single crystal 7aAs cells, which werepreviously used e)clusively in space applications, are now developed for terrestrialapplications, at very high concentrations, to produce near=cost=effective electricitygenerating power plants.

1urther technical advances relate to the production of large area 9full panel siBe;polycrystalline, microcrystalline and amorphous thin films in both silicon and othersemiconducting materials. 1or silicon, this is leading to much less material costs andlower production costs. 1or other materials such as Cde and CI7* it has raised the

possibility of higher efficiency modules 9(< percent; with simple productiontechnology and subse#uent low cost. hese and other technological advances have

been incorporated in new production facilities opened in the last three years in Europe9*hell, 4 *olar;, the 5* 9Canon=5nisolar; and Australia 94 *olare);.

&.&.& Recent industry trends+

6ne trend in the 2 industry worldwide has been the involvement of all ma!orpetroleum companies in the ownership, direct production and promotion of solarenergy, especially photovoltaic electricity production. his involvement, which

followed oil industry mergers, resulted in amalgamations 9eg. 4 *olar and *olare);and new, larger scale 2 production plants in Australia, Europe and 5*A which mayrealise substantial economies of scale.

his is a sign of the maturity of the 2 industry and of potential gains, due toeconomies of scale, achievable with these plants 9(' to (''%8$yr;. his latter figureis predicated on the e)plosion in the 2 market worldwide 9variously estimated at -' to 03 percent per year for several years, with no sign of levelling off;.

As an e)ample and according to 5* oE, the level of shipment for 5* manufacturersin ( was ??,''' k8p, up 3& percent from (< levels. Interestingly a large

proportion of this increase was aimed at the grid connected market rather than theusual standalone, remote area supply market. It is thought that this is a strong


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indication that 2Ds near future growth will certainly include a large market centredon urban applications.

&.&.- Economics and applications of 2 electricity+

Concomitant with the above, a substantial decrease in the price of cells and moduleshas occurred overseas since (&$8p to 5-.0$8p. 95* oE;. hese

prices do not reflect the above mentioned efficiency gains or economies of scale,which are e)pected to flow through in the ne)t three to five years.

In ew /ealand, prices range upwards from appro)imately ('$8p depending on thesiBe of module and whether they are bought in bulk.

1or complete functionality, 2 modules re#uire various components such as charge

controllers, inverters, batteries and safety disconnects. hese components add afurther estimated 5(=-$8p to the price depending on the siBe of the installation. Inmost of their manifestations, 2 power systems are versatile as to their siBe and

power output, from microwatts for calculators to megawatts and larger for central gridconnected power stations.

he possible markets for these systems are also diverse, often with #uite different andopposing re#uirements. he main applications can be divided into four broad sectors,namely consumer products, industry applications, remote area supply, and two distincttypes of grid connected systems.

Consumer products 9calculators, watches, toys;, individual power supplies

9caravans, mobile homes, boats;, and individual supplies for novelty products9home security, garden lighting, car sunroofs, fans, and battery chargers; werethe first market for 2.

here are a number of applications where 2 systems are sold to a service

industry, which then uses these for its own purposes, in its products orservices. 1oremost in this area are Fprofessional systemsG provided bycompanies active in the communication industry and the cathodic protectionindustry. ew /ealandDs electric fence industry is also a substantial and good

e)ample in this category of applications.

*tandalone power system 9*A*; applications include small to medium scale

2 technology, ranging between hundreds of watts and a few kilowatts, tosupply services in regions away from the main distribution grid. his isthought to be a pivotal growth area for the 2 industry in the coming decadein both industrialised and developing countries. he range of servicesincludes water pumping, water treatment, electric supply for small industry,domestic, medical and institutional uses 9houses, schools, clinics, small shops,farms; and communication links, both local and long distance via telephone,television and radio.


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7rid connected distributed supply system applications are a newer but

vigorously growing e)ample of 2 use in the urban environment. hesesystems are simpler than *A* as they re#uire only 2 panels and inverter to

provide AC voltage and connect to the local distribution grid. he mainelectricity supply acts as a storage facility, receiving electricity at times of 2

surplus and supplying it at times of 2 deficiency. Agreements and standardsfor electricity transfer in both directions are usually re#uired. hese systems

provide electricity at the consumer end of the distribution chain and competewith the retail price of electricity

7rid connected power plant applications have been trialled overseas to a siBe

of N(%8. hese include both full scale central 2 stations feeding power tothe distribution grid, and embedded generation 2 systems used to correcteither overloads or degraded power #uality at critical points, 9thus deferringsubstantial capital and maintenance e)penditures on transformers, lines etc;. Avery successful illustration of this embedded application is found in the

Kalbarri &'k8 2 system in 8estern Australia.

In ew /ealand, commercial e)amples of all the above applications, e)ceptcentralised and embedded power systems, can be found. he largest applicationsinclude 2 and hybrid *A* for isolated telecommunication and weather monitoringsites, for marine safety devices along the coast of ew /ealand, and for electricfences and navigation lights. 4oth these last products are e)ported overseas. hereare numerous applications of 2 as battery chargers for caravans, holiday homes and

boats. Also, more recently, it is estimated that around a thousand homes have beene#uipped with 2 power supplies, both off grid and grid connected, to provide

electricity for household loads across the country.

he 2 industry in ew /ealand comprises mainly distributors of imported modulesand components as well as an e)tensive network of e#uipment installers. *omeancillary e#uipment, such as battery chargers and more recently inverters, have beenmade locally on a small scale. o commercial modules or cells have been produced in

ew /ealand.

he variability in siBe of 2 installations makes it difficult to calculate an averageprice for an average installation. As a conse#uence 2 systems are most often #uotedon a Fpeak watt 98p;G basis. he price in ew /ealand has been around ('=(&$8p

for some time with other components adding a further 3 to ('$8p to the systemcost. his has made 2 strictly economic mostly in areas remote from the distributiongrid, where the cost of grid e)tension is of the order of &',''' to -',''' 9around'.3 to (km of electricity line;.

In other countries grid connected urban supplies are becoming a main growth area in2 applications.

As well as the importers mentioned, ew /ealand oil companies *hell and 4, as wellas Canon, have published their strong intention to import and supply 2 modules andsystems in ew /ealand.


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-. P#esent "nd &otent"l &enet#"ton n New Ze"l"nd/

210 Sol"# t(e#m"l con!e#son

E)cluding applications using natural conversion processes, such as salt production atlake 7rassmere, it is estimated that the present yearly sales of solar thermal systemsincludes 0'''m& to 03''m&of collector area for swimming pool heating and (&''units 9e#uivalent to 0'''m& to 3'''m&; for residential solar hot water. 7iven anaverage energy production of &3'' k8h per year from each hot water system, thisyields a yearly increase in energy produced from solar thermal 9pool and residential;in ( of ((,3''%8h.

As solar thermal is a well established technology in ew /ealand, it is possible toassess its present level of penetration and its overall contribution to the energy budget

in the last few years. In practice, it has proved difficult to assess the total number ofsystems installed since (',''' ) &3''k8h$yr;. hiswould take the installed capacity to -'' 78h per year by &''- and an estimatedma)imum >'' 78h per year by &'('. E)perience shows ma)imum uptake is aroundhalf of housing stock.


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5nder these scenarios solar thermal will substitute for fossil fuel generation. hemitigation achieved will depend on the mi) of other generation going in over this

period. 6n the basis that combined cycle gas will still be significant at this time, thethree scenarios would mitigate from >''' to ?',''' tonnes of annual C6 &emissions

by &''-.

*hould either of these increases occur, the re#uired production can be easilyaccommodated by e)pansion and !ob creation in the present manufacturing facilitiesin ew /ealand and by increases in imports, mostly from Australia. he largere)pansion envisaged above would provide increased employment for between 3''and


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be calculated assuming all new housing stock 9&(''' per year; is e#uipped with roofintegrated 2. he uptake would then be boosted to more than -(.3 %8 per year.his is >' times the business as usual scenario for &''-.

In terms of installed capacity and energy produced per year, the above four scenarioslead to the following estimates for the year &''-+

*cenario Installed capacity Energy produced C6& reductions

4usiness as usual &.3 %8 &.


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Summ"#$ o, sol"# s$stems

In summary, it is instructive to detail the hypothetical level of output 9in e#uivalentelectricity units; that could be achieved by each technology in ew /ealand as thelifecycle cost of production of that output decreases from its present level to a level

e)pected in the ne)t five years.

1or solar hot water, the present lifecycle cost of producing a k8h e#uivalent can beestimated from the e#uipment and maintenance costs 9 0,''';, the lifetime of thee#uipment 9&' years;, and the total number of electricity e#uivalent units producedduring that lifetime 9&'yr ) &,3'' k8h$yr;. he value of < H (& c$k8h obtainedindicates that solar domestic hot water is cost competitive with retail electricity tariffsthroughout ew /ealand and the ma)imum yearly output from this source is onlylimited by the number of systems that can be installed.

7iven a value of -&,''' installed systems, the potential output is about


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/ig!re :. Pro@eced 1oenia( oa( year(y conri-!ion 7in GW" 1er year e(ecriciye5!iva(en< fro4 so(ar ec"no(ogies as a f!ncion of "eir !ni 1rod!cion cos in Ne0Zea(and 7in cens 1er 8W" e5!iva(en


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(.( Tec(nc"l -"##e#s+

*olar technologies are mature 9solar thermal;, mature in some niche applications 92

H stand alone; or near=market 92 = grid connected;.

1or the solar thermal industry, technical barriers have been mostly resolved, at leastfor low temperature conversion. *ystems have e)isted for some time now withsufficiently high efficiency at low cost to yield a positive return over their operatinglife in a number of applications.

1or mid temperature systems suitable for implementation in ew /ealand as for 2,the technologies are both ready for niche market applications and would benefit fromfurther research and development to reduce costs and open new markets. he

breakeven point for a typical grid connected 2 installation at a ew /ealand urban

site can be from (3 to &' years-. he lifetime of the panels is guaranteed by themanufacturers for &' years.

"ence 2 can be considered a viable cost for cost replacement for centralisedelectricity generation even in well=reticulated cities. 1urther research anddevelopment already taking place will reduce materials costs and production costs,making 2 a preferred investment option even in these applications.

(.& %ost -"##e#s+

he main cost barrier to the dissemination of solar technologies is their total cost 9andhence initial capital investment; to the users, compared to alternative supply. 1orsolar thermal systems this cost is lower over the lifetime of the system. 1or 2 thiscost is already close to breakeven. "owever even in this latter case, the cost barrier isnot a simple reflection of economics alone it partly e)ists because the market doesnot take into account all the costs and benefits involved.

he cost of 2 9compared to coal, gas or even large hydro based electricity; does not,as yet, factor in the benefits of clean electricity production and an environmentallyfriendly image or e#uivalently traditional technologies do not internalise the costs of

environmental damage and international obligations. he absence of this pricedifferential is a barrier to adoption of 2 technology in particular.

resent competitive costs of traditional methods of electricity production reflect areduction in costs through years of implementation and F hands=on F e)perience. hiscost reduction through Ftechnology learningG is yet to accumulate for 2 in ew/ealand.

(.- ."#ket O#g"ns"ton"l -"##e#s+

-Market opportunities for dispersed photovoltaic energy sources in N I. *anders and A. 7ardiner,Industrial Research Limited &'''.


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he main immediate markets for solar energy technologies in ew /ealand are theresidential and commercial building industries and by implication, the electricityindustry as a whole generators, lines and retail companies. hese markets are by farthe most appropriate for solar technologies as they deal in space heating, water

heating and electricity. *olar technologies are eminently suited to providing thesere#uirements by on=site generation, in competition with centralised generation ande)tensive distribution lines.

"owever, the building industryDs traditional conservatism, 9and that of associatedtrades and professions= builders, carpenters, plumbers, architects;, a lack ofawareness, understanding and e)perience of these technologies constitute a ma!or

barrier to their adoption.

An inade#uacy of traditional financial markets for solar technologies arises from thevery nature of renewable systems. hese are often capital intensive but have ne)t to

nil ongoing and maintenance costs. Economic means of analysis such as paybackperiod, used e)tensively for traditional assessments, are disadvantageous to solartechnologies, for which lifecycle costs are more appropriate. hese incorporate someassessment of reliability, low maintenance and nil fuel costs.

here is also in ew /ealand an inability to capture the benefits of solar technologyby users. *olar does not add value to the price of a house, it is not sufficiently valuedat national and regional levels or in regulations and standards, hence has little or nomarketable value at present.

he organisational structure of the residential and commercial building industryengenders conflicting interests for investors and users for an investor houses and

buildings capital costs are to be minimised, for purchasers and users, on=going andlifecycle costs need to be reduced.

1inally there is a lack of ade#uate information to ensure public awareness of thetechnology and its advantages. his lack of awareness spreads through to all sectorsof this industry and, to a lesser e)tent through the electricity industry.

Documents

034ca-EECA---Solar-in-NZ-May-2001 (1)