PASSIVE SOLAR ENERGY AS A FUEL

Transcription

1 PASSIV SOLAR NRGY AS A FUL A study of the urrent and future use of passive solar energy in buildings in the uropean Community. RPORT ON BACKGROUND MATRIAL AND RSARCH The Commission of the uropean Communities Diretorate General XII for Siene, Researh and Development

2 PUBLICATION N 2 UR 1395 C of the Commission of the uropean Communities, Sientifi and Tehnial Communiation Unit, Diretorate-General Teleommuniations, Information, Industries and Innovation, Luxembourg. CSC-C-AC, Brussels-Luxembourg, 199 Legal Notie: Neither the Commission of the uropean Communities nor any person ating on behalf of the Commission is responsible for the use whih might be made of the following information. The researh for this report was arried out in 1989/9 under the guidane of Theo C Steemers, CC DGX11 by: The CD Partnership, merald Street, London, WC1N 3QL, UK (Simon Burton, Alison Crompton, John Doggart, Katy Steele) with the assistane of: Rafael Serra, Owen Lewis, Alex Lohr, duardo de Oliveira Fernandez, Peter Wouters, George Henderson, ri Durand, Nik Baker, John Goulding, Prof Jose Abel Andrade, Romain Beker, Andre de Herde, Henrik Lewaetz, Mat Santamouris, J M Boonstra (Woon nergie), Gianni de Giorgio, Paolo Oliaro, Maria del Rosario Heras, Dr Kuebler.

3 CONTNTS PAG NO INTRODUCTION Bakground Objetives Sope Definitions Tehnial solar ontribution Passive solar tehnologies Passive solar design and the user INFORMATION SOURCS General Published material uropean ase studies xpert assistane and questionnaires Conlusions on information ,J FORCASTING TH FUTUR OF PASSIV SOLAR NRGY Review of systems, omponents and materials xisting and projeted ost benefits Review of non-tehnial obstales to the use of passive solar design Other fators affeting the adoption of passive solar design MTHODOLOGY FOR CALCULATIONS General Domesti heating Domesti ooling Non-domesti energy Non domesti - existing foreast Non-domesti - tehnial Pollution RSULTS nergy - urope wide nergy - individual ountries Pollution redution CONCLUSIONS Ahievement of the 11 tehnial 11 Where effort should be put (1)

4 CONTNTS (ontinued) PAG NO 7 FIGURS Total fuel use in the uropean Community 199 Fuel use in housing and non-domesti buildings Solar energy ontributions - All uropean Community Solar energy usage in the uropean Community 199 Population in the uropean Community 199 Atmospheri pollution - All uropean Community Nulear waste savings - All uropean Community Belgium - solar energy and pollution savings Denmark - solar energy and pollution savings.frane - solar energy and pollution savings Germany - solar energy and pollution savings Greee - solar energy and pollution savings Ireland - solar energy and pollution savings Italy - solar energy and pollution savings Luxembourg - solar energy and pollution savings Netherlands - solar energy and pollution savings Portugal - solar energy and pollution savings Spain - solar energy and pollution savings UK - solar energy and pollution savings (2)

5 1 INTRODUCTION 1.1 Bakground 1.2 Objetives 1.3 Sope The Commission of the uropean Communities has supported the use of solar energy to provide heating and lighting to buildings sine 198. As a part of its support, this study was ommissioned by the CC in 1989 to assess the amount of passive solar energy whih ould be utilised in buildings over the 2 year period up to the year 21, and to estimate the onsequent redution in the use of fossil fuels and in the resulting pollution. The sun diretly provides heat and light to almost all buildings and the amount of this solar energy an be inreased by speifi design. It is therefore useful to quantify this solar ontribution. The energy used by buildings is urrently reorded in terms of their eletriity, oal, oil and gas onsumptions for the various funtions - heating, lighting, ooling, hot Water, proess loads et. The purpose of the study is to be able to add in the use (or onsumption) of solar energy, so that due redit an be given to buildings with a high utilisation of solar energy and whih therefore redue the need for auxiliary energy use. This onept is also applied to overheating and the onsequent use of auxiliary energy for ooling. Buildings in all limates an be designed to redue or eliminate overheating and just as the solar ontribution to a heating demand an be quantified, so an this ontribution of passive solar design to a ooling demand. This is disussed further in setion 1.4 whih deals with definitions. Whilst the redution in the use of "onventional" energy soures is desirable in the traditional terms of ost savings, onservation of dwindling fossil fuels et, the growing awareness of the problems of global pollution have highlighted the importane of energy onservation and the use of renewable energy soures in averting global disaster.. Thus a major objetive of this study was to quantify the redued pollution resulting from the substitution of auxiliary fuel use by passive solar energy. This study overs energy use in both housing and nondomesti buildings in all 12 CC ountries. The use of passive solar energy for heating, lighting and ooling of all buildings is inluded where appropriate. The exat definitions of the "passive (3)

6 1.4 Definitions solar ontribution" to eah area are important and these are disussed in setion 1.4. The study is limited to general assessment and foreasting in several areas, with more detailed analysis in the area of heating in houses where researh and information olletion has been more ommon in reent years. As more data in individual ountries beomes available, it will be possible to provide a more detailed estimate. Setion 2 overs the sope of information soures used. In terms of end results, the study assesses the amount of energy from "onventional" soures that is urrently replaed by passive solar energy and how this ould hange over the next 2 years if passive solar design tehniques were widely adopted both in new buildings and in refurbishment. The resulting savings in the whole range of pollutants produed by onventional fuels, inluding nulear power, are analysed on a ountry by ountry basis. The study does not inlude other uses of solar energy in buildings suh as ative solar heating, solar water heating, photovoltais or solar heating for agriulture. It is not possible to measure the amount of solar energy used for a partiular funtion in the same way as one an measure the amount of oal, oil, gas et. As far as possible solar energy has been measured by its substitution of eletriity or gas use, et, fatored bak to primary energy units. There is still a need to larify several aspets and define the boundaries. Passive solar heating. nergy from the sun s rays entering the building envelope through a window or other transparent or transluent part of the envelope (Trombe wall, roof, sunspae et.) whih is useful in replaing auxiliary heating or improving omfort onditions within the building. Annual solar heating ontribution. The total passive solar energy whih raises temperatures towards omfort levels throughout the year (not only during the "heating season"). The base line for measurement is taken as the internal temperature of the.building resulting from the ambient (external) temperature plus internal gains from oupants, ooking, lights, equipment and hot water. (4)

7 Passive solar ooling. Building design features whih redue the entry of sunlight into a building (overhangs, blinds, shutters, et), promote passive ventilation (ross ventilation measures, stak ventilation et) or redue maximum temperatures (thermal mass, water ooling et), to redue auxiliary ooling loads or improve omfort levels. Passive solar ooling ontribution. The ontribution of passive solar design to satisfying the "ooling demand", whether or not the remaining demand is satisfied by auxiliary ooling or aeptane of overheating. The base line for measurement is taken as the temperature above whih auxiliary ooling is ommonly in use. (This varies between different building uses). Daylighting (as a passive solar measure). Building design whih maximises the entry of daylighting into a building (form, window size and loation, skylighting, refletors, et) or redues the unneessary use of auxiliary lighting (responsive ontrol systems), to provide aeptable levels of illumination. Non-domesti daylighting ontribution. The base line for measurement is taken as the urrent level of auxiliary lighting. The daylighting ontribution is the redution in auxiliary lighting use due to speifi building design and inorporation of responsive ontrol systems. The assumption is that the auxiliary lighting is normally in use during daytime hours irrespetive of demand. Domesti daylighting ontribution. No ontribution has been onsidered sine auxiliary lighting is not normally used in houses during the hours of daylight, and design or ontrol improvements would not normally redue auxiliary lighting or improve omfort. 1.5 Tehnial solar ontribution The priniple alulations within the study are aimed towards produing the "Tehnial Potential solar ontribution" in the years 2 and 21. This is the tehnially possible target based on existing proven designs and tehnology and estimated building and refurbishment rates. It is based on all new and refurbished buildings inorporating appropriate passive solar measures but taking into aount fators suh as orientation and overshading. Thus the tehnial ould never be ahieved in pratie, though various influening fators ould at towards reahing this target. (5)

8 The following influening fators have been identified and their effets examined: Fuel pries Legislation Publi pressurejsoial hange Global environmental onerns Climati hange Inentives Tehnial advanes Tehnology transfer Competition with other energy saving measures 1.6 Passive Solar Tehnologies The proven passive solar designs and tehnologies onsidered are as follows: Heating. Orientation and layouts (internal and external) Diret gain through windows; Sunspaes; Thermal mass; Convetive loops for distribution of solar gains; Indiret panels (Trombe walls). ooling. Fixed overhangs; xternal shading devies; Blinds and shutters; Thermal mass; Natural ventilation, inluding stak ventilation; Humidifiation. Lighting. (Non-domesti only) Speial designs to allow entry of daylight; Narrow plan designs; Light wells, light refletors; Photo-eletri ontrols. There are other tehnologies, produts and tehniques that an be used to enhane solar performane and these will be appliable to various situations. The effet of these has been onsidered separately and this is disussed in setion 3.1. (6)

9 1.7 Passive solar design and the user The main purpose of this study is to assess the ontribution that passive solar design an make to reduing auxiliary fuel use in buildings and thus reduing environmental pollution. However, passive solar design has other benefits, partiularly for the users or oupiers of the buildings, and these in turn will affet the suess and growth of passive solar design. In housing the ontribution of passive solar design may not in pratie redue auxiliary fuel onsumption but may be used to inrease omfort. This is partiularly true with ooling where passive ooling measures will redue maximum temperatures, though auxiliary ooling would not be available or used.. However, there is a trend towards the use of more auxiliary heating and ooling as standards of living rise, partiularly in less developed ountries suh as Portugal and Greee.. Thus the study reognises the value of solar gains both in raising standards of omfort and reduing auxiliary fuel use. In the non-domesti setor the same trends are disernable though prinipally onerning ooling. The study antiipates a steady growth in the use of auxiliary ooling in non-domesti buildings. The CC Projet Monitor series olleted user response to passive solar buildings. In both houses and nondomesti buildings, users liked the buildings with few exeptions, though for different reasons. Oupiers of passive solar houses liked them for the light and airy feeling and generally for their appearane and omfort. Sunspaes were universally liked both as pleasant spaes and often for the 11 extra 11 spae they provided. There was some evidene that the houses had greater market values and that oupiers wished to move to another solar house if they were to move. The pereived benefits of non-domesti solar buildings in addition to being light and omfortable, were often related to the ativity arried out in the building. Thus passive solar shools provided the right environment for learning about eologial issues, and a solar offie/fatory was used to demonstrate the use of the environmental ontrol systems manufatured in the building. Passive sola.r design in non-domesti buildings an also help to alleviate general building problems suh as Sik Building Syndrome. A study by the Building Servies Researh and Information Assoiation (BSRIA) the "Sik Building Syndrome", in the U.K. indiates that it is a omplex "oktail" of fators whih ause (7)

10 the effet, whih an be a serious problem leading to low user moral, absenteeism and loss of produtivity. Several of the ausal fators relate to building design and operation and these may be avoided or redued by passive solar design, for example:- - low fresh (outside) air ventilation rates; - - low air movements; some types of heating and ventilation systems; - mehanial ventilation; - poor ontrol of building servies; fluoresent lights (glare and fliker); - proportion of daylight versus artifiial lighting; - non-openable windows; - tinted or mirrored glass. Passive design in non-domesti buildings uses more daylighting, elimination or redution of aironditioning, natural ventilation and greater use of passive solar heating and thus puts building users more losely in touh with the outside environment. Avoidane of any tendeny towards "Sik Building Syndrome" is important in the design of non-domesti buildings and passive solar design an be an important part of the strategy. (8)

11 2 INFORMATION SOURCS 2.1 General The study methodology was to use published data, ase study information and estimates of future trends where possible, supported by expert opinion and estimates where neessary. Information searhes in the UK revealed that published data are not available in a large number of areas (see setion 2.2). Subsequent approahes to experts in the other CC ountries onfirmed that data and information are frequently simply not available. In some ases, in some ountries, the information required was thought to be available but the time and resoures within the study were not suffiient to gather it together into a usable form. The next approah was to use experts in various ountries (see setion 2. 4) to make estimates for their ountries where information was not published. In some ases experts were not able or prepared to make suh estimates. The last approah was for the study team in the UK to make estimates based on trends and omparison with other ountries where information or estimates were available. 2.2 Published Material The main soures of published information used in the alulations were as follows: CC urostat Review Building Servies Researh and Information Assoiation (BSRIA). statistis Bulletins Building Researh stablishment BR Homes and BRDM CC Projet Monitor Series (Housing stok, population, non-domesti energy use, breakdown of energy by soure) (UK house building refurbishment and demolition rates, ooling information) (UK house energy use) (Passive solar ontribution throughout urope, general energy onsumption data) (9)

12 Martin Centre "Passive Solar Heating in xisting Housing" urisol "Pollution Redution Through nergy Conservation) nergy Tehnology Support Unit (TSU) Harwell "Report 1142" (N. Baker) Watt Committee on nergy. "Passive Solar nergy in Buildings" Building Researh stablishment "Daylighting as a Passive Solar Option" CC Building 2 Projet CC/. Hohmeyer "The Soial Costs of nergy Consumption 11 TSU "nergy Use and ffiieny in UK Commerial and Publi Buildings up to the year 2 11 (UK housing heat losses) (Breakdown of house energy use by soure) (Sunspae performane) (Non-domesti energy) (nergy use in nondomesti buildings. Lighting estimates) (Cooling in non-domesti buildings) (nvironmental osts of eletriity prodution) 2.3 uropean ase studies Projet monitor. The 5 ase studies of monitored passive solar buildings in urope produed in the C..C Projet Monitor series have been analysed to produe data useful to this study. The series. ontained 27 groups of "multiple" housing, 1 individual houses, 2 housing refurbishment projets, 1 sheltered housing sheme and 9 non-domesti shemes. Multiple Housing In more than a third of the multiple housing shemes, passive solar gains ontributed more than 3% to the spae heating demand. Although the highest ontributions, around 7%, were in southern half of urope, Southern Frane, Spain and Italy, (1)

13 ontributions of up to 4% were obtained in the north. Although many projets ahieved less than 3% ontribution, the analysis suggests that with good design and good operation 3% solar ontribution is obtainable. The perentages of solar ontribution are not diretly related to latitude. The total amount of solar energy utilised per dwelling was above 3,3 kwh per year in a third of the projets and this applied to both large and small dwellings, in both northern and southern limates. Standardising for floor area between large and small houses shows that 3 kwh per square metre is ahievable at all latitudes. High solar perentages an only result from suessful solar design and even where the heat load of a building has been redued by areful use of insulation measures, high perentages were still ahieved. However finanial savings and environmental pollution redution result from large absolute energy savings. Naturally there is a trend towards smaller savings resulting from solar gain as overall heat demand redues. Nevertheless at all levels of heat demand (measured in kwh/m 2 ) there is a wide variation in useful solar gain, with a fator of 3 or more between worst and best (Diagram 4). The onlusion is that even with well insulated buildings, worthwhile passive solar ontributions an be ahieved. All buildings benefit from solar.gain to some extent even if not speifially designed to do so. On average the solar gain for the. existing housing stok is estimated to vary from around 1% to 15.5%, for the northern limates. To take one example, the UK average solar energy utilised is 25 kwh, a figure refleting the low levels of insulation (and therefore high heating demand) of the existing housing. With better insulated new housing, and further insulation to existing housing, the amount of solar heating would derease over time. However this an be.hanged if passive solar measures are inorporated. Thus the ahievable' solar gain of 33 kwh in a well insulated, passive solar house, represents an additional saving of around 15 kwh, over that whih would be ahieved without any speifi solar design. Individual Houses The larger individual solar houses had solar ontributions of 35% and above in 8 out of the 1 examples and large energy savings of above 85 kwh were ahieved in nearly half the projets. ven where the heating demand per unit area was small, high perentage and absolute solar ontributions (11)

14 were ahieved in the best examples. It is interesting that latitude has less influene on these figures than dwelling size and heat loss. The effet of the oupants in ontrolling their houses was frequently thought to have been one of the most important influenes on the level of solar gains ahieved. Housing Refurbishment Adding passive solar features to an existing building or inorporating solar features during refurbishment, has great for the wider use of solar energy, due both to the large numbers of existing houses and the high heating demand of the older housing stok. The two examples inluded, Lievre d'or in Frane and Baggesensgade in Denmark, use inreased areas of south faing glazing, Trombe walls and sunspaes. Solar ontributions of 2% and 27% were ahieved and Baggesensgade reorded the highest overall solar ontribution of all the projets, nearly 22, kwh per year per flat. Non-domesti Buildings It is impossible to assign general figures to the solar energy usable in non-domesti buildings from those projets in Projet Monitor, due to the wide variety of designs and uses.. In Spain at Polysportive sterri sports hall, passive solar energy supplied 94% of the heating load and at Los Molinos ollege, 8% (the remainder of the heating load. being supplied by internal gains). In more northern latitudes, the JL building in the UK ahieved 29% solar ontribution. Large and valuable solar ontributions are learly possible. For example shools are well suited to passive solar design in at least two respets, they are oupied primarily in daytime when solar gains are available diretly, and they are not oupied in the hottest summer months, so that overheating is less of a problem. However the passive solar design of non-domesti buildings is likely to be tailored more speifially to the building and its uses, ompared to housing where similar solutions are satisfatory aross the range of designs Building 2. Draft brohures produed as part of the CC "Building 2" projet were studied to investigate ooling loads and the ontribution of passive solar design to reduing or eliminating auxiliary ooling demand. Building 2 is a series of 36 design studies of non-domesti buildings arried out with the help of uropean experts, (12)

15 drawing on lessons learnt and tehniques developed through the CC 1 s researh and development programme on solar energy appliations to buildings. Nine projets referred to ooling loads and these are summarised below:- 1. Portugal (north) Business Innovation Centre Central zone only ooled 15 kwh/m 2 Remainder naturally ooled Spain (Barelona) Hotel/Restaurant Frane (mid north west) Business Development Area Portugal Muniipal Offies and Conferene Centre Greee (north) Shool of Mediine Greee (Crete) Hotel Greee (Crete) Holiday Complex Spain (Madrid) duational Centre Greee (Paras) Holiday Complex No auxiliary ooling needed. Normal ooling load 6 kwh/m 2 As designed no auxiliary ooling needed. No auxiliary ooling needed. Normal ooling load 6 kwh/m 2 As designed no auxiliary ooling needed. Cooling load 3 kwh/m 2 Normal ooling load 76 kwh/m 2 As designed (with shading 48 kwh/m 2 Normal ooling load 6 kwh/m 2 As designed.5 kwh/m 2 Normal ooling load 17 kwh/m 2 As designed no auxiliary ooling needed. It was onluded that these projets indiated that most buildings ould be designed to avoid the need for auxiliary ooling. In terms of typial annual ooling loads (per m 2 ) with traditional designs it is not possible to (13)

16 dedue an average value. The range quoted is between 76 kwh/m 2 and 17 kwh/m Portuguese experiene. A onsulting engineer in Portugal supplied some information for ooling in non-domesti buildings in a entral Portuguese loation (39 north). Total demand for ooling, inluding fan power, was estimated at 55 kwhjm 2 This ould be redued to 28 kwhjm 2 with the use of low emissivity double glazing and good thermal insulation in a newly designed building. It was onluded that the ooling load alone (exluding fan power) would be approximately 45 kwh/m 2 and that a sophistiated passive solar design ould redue the ooling requirement to almost zero U.K. xperiene. Researh is in progress for TSU in the UK in assessing the total energy use of a number of reent offie bloks broken down into uses. Preliminary results indiate a maximum of 35 kwh/m 2 energy use for refrigeration in onnetion with air-onditioning (fan power is inluded as a separate item). G. Kasabov in a publiation for the RIBA in 1979 "Buildings The Key to nergy Conservation" gives ooling energy used in four low energy non-domesti buildings. These vary from 5 kwh/m 2 to 35 kwh/m 2 The Building Servies Researh and Information Assoiation (BSRIA) quotes (1989) a survey of offie aommodation available in London, showing that 6% of the floor area had air-onditioning. From this information the amount of energy used for auxiliary ooling in the U.K. has been estimated. 2.4 xpert assistane The following experts provided information and assistane:- overall Rafael Serra Alex Lohr Owen Lewis Nik Baker Universitat Politenia de Catalunya. Spain. Buro fur nergiegerehtes Bauen. W. Germany. University College, Dublin (UCD). Ireland. The Martin Centre, Cambridge. UK. (14)

17 Country speifi Belgium Denmark Frane w. Germany Greee Ireland Andre de Herde, Universite atholique de Louvain. Henrik Lewaetz, Danish nergy Ageny. ri Durand, Agene Fran9ais pour la Mai trise de 1' nerg_ie. (AFM). Dr. Kuebler, Bundesministerium fur Wirtshafte. Mat Santamouris, Protehna Ltd. Owen Lewis, John Goulding, UCD. Italy Gianni de Riera. Giorgio. Progettazione & Luxembourg Netherlands Portugal Spain.UK Romain Beker, Ministere de L'energie. Woon nergy. Prof. Jose Abel Andrade, Universidade Do Porto. Maria del Rosario Heras, CIMAT. The CD Partnership. Information was requested from the ountry experts by means of a questionnaire overing a whole range of matters. Respondents were requested to indiate the soure of information where appropriate. Where.information was not available, the experts were requested to make estimates sine it was felt that their estimates were likely to be more aurate than those made by others. 2.5 Conlusions on information xhaustive library searhes partiularly at South aank Polytehni Information servies and Queen Mary College Library (uropean Doumentation entre) demonstrated that while basi data for energy use in buildings are available aross all CC ountries, other more detailed information for CC ountries is not available from entral soures. Data and some future preditions for the UK were obtained from a wide range of published and unpublished soures and organisations suh as the Building Researh stablishment, so that a reasonable piture of energy use in buildings in the UK was onstruted for the present and for the future. (15)

18 In many other uropean ountries it seems likely that similar information is not available, or that its olletion would be outside the timesale of this study. Clearly muh more work has gone into the olletion and publishing of data onerning the domesti setor ompared to the non-domesti setor. Information about the non-domesti setor has proved muh harder to find and fewer projetions have been made for the future. Whilst researh on energy use in some individual ategories of buildings, suh as shools, is available, the wide range of building types and uses makes generalisations of non-domesti energy use very diffiult. Before this study very little effort seems to have been made and very little published, in this area. 3 FORCASTING TH FUTUR OF PASSIV SOLAR NRGY 3.1 Review of likely developments in systems, omponents and materials Heating. Considerable experiene is available in passive solar heating in houses and muh of the basi systems and omponents are well developed and reliable. These inlude: - diret gain - use of thermal mass - use of sunspaes - thermal movements - air heating panels and Trombe walls Small performane improvements are possible in suh areas as the transfer of warm air from sunspaes and in the use of air heating panels and Trombe walls. It is not felt that these improvements will signifiantly improve on the overall solar performane figures adopted in the study within a 2 year period. One produt is likely to make a signifiant effet on solar energy usage for heating - transparent insulation. There are several produts and systems under development inluding honeyomb systems and "aero gels" and a whole range of appliations an be foreseen. These inlude inreased "glazed " areas where diret views are not required (or substitution of transparent insulation for normal glazing), use on air and water heating panels and ladding of walls of new and existing buildings. Take up of the theoretial will depend greatly on material and onstrution osts, dealing adequately with over heating and aestheti onsiderations. A (16)

19 separate estimate has been made within the spreadsheet alulations of the tehnial resulting from the use of transparent insulation in housing. Some passive solar heating systems or elements are urre~tly not thought to be widely appliable nor ost effetive enough to signifiantly improve overall solar performane figures. Roof spae olletion systems are usable and an ontribute useful solar gains in both newbuild and refurbished housing but it is unlikely to beome widespread due to high apital osts, the need to use fan power and problems with dust distribution. Thermal storage, using rok, brik or water stores have been used for diurnal storage of solar gains but performane is poor and it is unlikely that they will beome ost effetive within the next 2 years. Storage using phase hange materials is still under development and similarly no signifiant ontribution is expeted over the period under onsideration. There are other passive solar systems or elements whih have been developed and used suessfully in partiular instanes, suh as multi-layer windows, refletive panels and speial air distribution systems, but their effet over the next 2 years on the total solar ontribution is not likely to be signifiant. There had been less development of systems and less reorded experiene for spae heating in nondomesti buildings. Figures adopted in this study for passive solar ontributions to non-domesti heating are based on fewer examples and realisation of the solar ontributions depend more on inorporation of systems and tehniques than on development of new produts et. Most of what has been said applies to both new buildings and refurbishment, exept that one again there is muh less experiene available in refurbishment Cooling. Passive solar ooling tehniques for housing are mostly appliable in southern latitudes, where they have been used for many years. Changing onstrution methods and the availability of auxiliary ooling have led away from passive ooling methods but the methods and omponents are well known and developed. No signifiant developments in systems, materials or omponents are envisaged within the next 2 years. {17)

20 The piture is more ompliated in the non-domesti setor. In southern latitudes passive tehniques have always been in use but the effet of the availability of auxiliary ooling, new onstrution systems and new, intensive uses of buildings, has been very signifiant. Shading systems and the use of thermal mass to modify temperatures need no development but more omplex ventilation and passive ooling methods, suh as solar himneys and use of ool air, while ommon in the past, need to be adapted and developed further in modern buildings. In this study it has been assumed that these developments will take plae over the next 1 years and thus their use has been inluded. In nondomesti buildings in northern uropean latitudes there has been less need for ooling and less use in the past. However produts and tehniques are available and the experiene of southern latitudes an be used. The more ompliated ventilation tehniques are not generally neessary for the smaller ooling loads and thus it has been assumed that adequate omponents and systems are urrently available and that there will be little further development The main area where development is required is in developing assessment methods for annual ooling loads and the ontribution of passive ooling tehniques and omponents. It has been assumed that this will take plae over the next 1 years. Lighting. Passive ontributions to redue auxiliary lighting have only been onsidered for non-domesti buildings. There are two distint areas of development, ontrols and inreasing daylight penetration into buildings. Photo-eletri ontrols that swith off unneessary auxiliary lights when not required are well developed and experiene is widely available. Inreasing the penetration of daylight into buildings is a developing area and systems, produts and materials are urrently improving, inluding light shelves, refletors and diffusors, narrow building widths, atria, and roof lights. The CC ompetition "Working in the City" (1989) has developed assessment tehniques and guide.lines, stimulated interest and given experiene on design for daylighting in non-domesti buildings throughout urope. Considerable development is still required to establish daylighting widely in.new building design and in refurbishment. The study has assumed that this development will take plae over the next 2 years. Thus. it has been assumed that lighting savings in this study ome prinipally from photo-eletri ontrol systems with a smaller ontribution from daylighting design. (18)

21 3~2 xisting and proieted osts and benefits The extent to whih passive design is adopted depends to a large extent on the osts and benefits attahed. Muh passive solar design need not have any additional osts attahed (e.g. orientation, reloation of glazing, adequate ventilation, thermal mass and natural daylighting strategies), though more areful design may be required, at least at first, to optimise on new design priniples. Other passive measures will always require additional funding, though if they beome a regular feature, osts will be lower than at present (e.g sunspaes, indiret panels, shading devies, stak ventilation, humidifiation,. some day lighting designs, light refletors and photo eletri ontrols). It should be remembered that some features have benefits other than in energy terms suh as sunspaes, atria and fountains for humidifiation, so that the osts put towards energy use, should be offset for these other benefits. The benefits resulting from passive solar design are threefold:- finanial, in terms of redued fuel onsumption; omfort, in terms of higher temperatures in winter or lower in summer; environmental, in terms of pollution redution, avoidane of "sik building syndrome", or improved. "quality of life". Traditionally.ost and benefit analysis of passive solar design has been arried out.using only the fuel savings and many of the basi passive measures have proved suessful on this riterion alone. Clearly fuel prie and future inrease in fuel pries,.have a major impat on this ost-effetive balane, and.though foreasting on fuel pries is impossible, it an be agreed that they will rise (in real terms) and thus passive measures will beome more ost-effetive in.future. The eonomi balane will also be affeted if environmental pollution osts are inluded, by a mehanism suh as the "arbon tax". An attempt. has be en made by Hohmeyer in a study for the CC, "The Soial Costs of nergy Consumption", to start to quantify the osts of pollution in the prodution of eletriity. Improvements in omfort levels are mostly taken as benefits by householders where auxiliary heating or ooling are not available or felt to be too expensive to use.. This is partiularly ommon in the.less developed ountries and with the lower inome groups. On the non-domesti side, improvements in omfort from a redution in (19)

22 overheating are likely,to be signifiant in southern latitudes, where auxiliary ooling is not ommon. The ontribution of passive solar design to environmental pollution redution is learly of great importane to the world as a whole. Traditionally this has only been reognised by some individuals and organisations but is likely to assume a greater importane in the future. As mentioned above environmental pollution is likely to be asted in the future and so enter the eonomi equation. The non-energy benefits of passive design relate to the internal environment, and inlude an improved "quality of life" and may assist in the avoidane of "Sik Building Syndrome" (see setion 1.7). Building users, organisations and ountries as a whole, will pereive the above benefits in different ways. In the home, fuel bill savings, inreased omfort and quality of life will be appreiated, possibly together with helping to redue atmospheri pollution. Organisations will appreiate fuel bill savings, improved omfort and quality of life, and avoidane of sik building syndrome in as muh as they make employees happier and more produtive. They may appreiate-the redution of environmental pollution though this may be from a marketing angle. At the national level, the benefits are in the redued fuel imports bill, the redution in environmental pollution and the improved effiieny of businesses through redued fuel bills. 3.3 Non-tehnial obstales to the adoption of passive solar design. Five non-tehnial obstales have been identified whih are thought to be largely responsible for the low adoption of passive solar design at present. Ianorane. There is ertainly a lak of knowledge amongst designers of passive solar design and the benefits arising. Within the building industry the workfore laks experiene of passive buildings and traditional ways an be diffiult to hange. Clients, funding organisation and speulators, will generally have little knowledge of passive buildings. Lak o.f demand. It is frequently laimed that there is a lak of demand for passive solar houses and other buildings i.e that users will not appreiate the design and will not be prepared to pay any additional apital osts nor operate the building to use the solar design to best advantage. (2)

23 Traditionally house builders and non-domesti developers see their role as "satisfying the market" Fear of problems or failures. Moving away from urrent pratie and the use of new ideas tehniques and produts leads to fear that problems and possibly failures will our. Few lients or designers will take these risks (as they see it) unless it an be demonstrated that adequate suessful experiene is available. Non-availability of materials and produts. Though materials and produts to enhane passive solar performane may be developed, they may not be widely known to designers nor available to builders. Non-availability of design and evaluation tools. To demonstrate the advantages of passive buildings, validated design tools are required. These need to be integrated into the design proess and understood by designers. At present design tools are available in the area of heating and reasonable evaluations an be made. Fewer validated tools are available for lighting and ooling alulations and this is likely to be an obstale to inorporating passive design in these areas. 3.4 Other fators affeting the adoption of passive design. The future adoption of passive design in buildings is likely to be affeted by several other fators whih are under the ontrol of governments. Leaislation. Introdution of passive solar design into building regulations as mandatory or optional for heating, lighting and ooling is possible, and has been used for example in Frane. Grants or other inentives. Finanial support for the use of passive designs ould be given and justified on being in the national interest. Grants for other energy onserving measures are quite ommon. Publiity and promotion. National publiity and information dissemination about the methods and benefits of passive solar design an be used with or without legislation or inentives. Numerous methods have been proposed and used. Fuel priing, arbon tax. Inreasing fuel osts via taxation an be used as a mehanism to improve the finanial paybak of passive solar measures and thus stimulate interest in passive design. duation. nsuring that passive solar design priniples are inluded in the eduation of arhitets and {21)

24 other designers, will in the longer term stimulate solar designs in pratie. Post qualifiation, inservie training in solar design an also be used to stimulate interest. (22)

25 4 MTHODOLOGY 4.1 General A omputer spreadsheet alulation systems ("Framework") was used as the basis for the analysis and projetions. The alulation sequene used is desribed in subsequent setions. For eah of the twelve CC ountries it is broken down into three parts, domesti heating, domesti ooling, and all non-domesti energy use (heating, ooling and lighting). The spread sheet system has several advantages mainly that it is "transparent" and thus an be examined by anyone, and that hanges and revisions an be made at any stage and almost immediately inorporated into the final results. 4.2 Domesti heating ASPCT Year 199 Present building stok ~ Typial dwelling energy analysis CALCULATION The total numbers of dwellings based on population and buildings stok per 1. Gross heating demand and how this is urrently satisfied by internal gains, solar gains and auxiliary heating (taking effiienies into aount). Gives "unplanned solar-gain" and auxiliary heating load broken down by fuel type for whole dwelling stok. MAIN SOURC urostat Review Building Researh st. (UK) Projet Monitor d xisting passive solar designed dwellings d on the number of new and refurbished ''passive solar dwellings" known, average "planned solar ontributions" and a fator to inlude all planned passive solar dwellings, gives total planned solar ontribution. Projet Monitor ~ Present summary of solar energy Sums present solar gain (unplanned and planned). (23)

26 Year 2 ~ New dwellings - tehnial solar gain~... Refurbishment d on estimated rate of new building, orientation, gross heat loss and estimated solar ontributions (diret gain, indiret gain and sunspaes) gives total newbuild tehnial solar ontribution. As above for refurbished dwellings BSRIA (UK) Projet Monitor ]_ Demolitions stimated rate of demolition of dwellings gives total number demolished. BSRIA (UK) ~ 2 summary of solar energy use. Sums solar gain in year 2. Year 21 Calulated as year Domesti Cooling Year 199 Gross ooling demand ~ Dwellings using auxiliary ooling J.. urrent ontribution of passive solar ooling design Year 2 No ooling demand onsidered for ountries in northern latitudes. For Portugal, Spain, Italy and Greee, 5% of dwellings stok was onsidered to have a ooling demand, and for Frane a 1% demand. Gross heating demand (per house) alulated for Greee (8 kwh pa), other ountries taken as 5 kwh pa. stimated perentages of dwelling stok that use auxiliary ooling, this is assumed to satisfy 1% ooling load. Assumed that in houses with a ooling load but without auxiliary ooling, passive design ontributes 5% to the load (the remaining unsatisfied load results in overheating). (24)

27 ~ Gross ooling demand 2 Dwellings using auxiliary ooling Q ase solar ooling ontribution. 2 Tehnial solar ooling ontribution Year 21 ~ Gross ooling demand ~ Dwellings using auxiliary ooling 1 ase solar ooling ontribution 11 Tehnial solar ooling ontribution (Still no ooling in northern latitudes). Same proportion of new building and refurbishment will have a ooling demand as existing stok (i.e. 5% and 1% Frane). Cooling demand per dwelling kept onstant. Assumed 2% of newbuild and 1% of refurbished dwellings (with a ooling demand) will use auxiliary ooling, but only 6% of this load will be supplied by the auxiliary ooling and 4% by passive solar design in newbuild (still 1% auxiliary ooling in refurbished dwellings). Sums 199 non-auxiliary ooled dwelling ontribution as above (3) with the 4% ontribution as above (5). In newbuild, taken as 85% of gross ooling demand and in refurbished dwellings, 7% (taken for all new and refurbished dwellings). Calulated as year 2. Assumed 3% of newbuild dwellings and 2% of refurbished dwellings (with a ooling demand) will use auxiliary ooling, with 6% supplied by the auxiliary ooling and 4% by passive solar design in newbuild (still 1% auxiliary ooling in refurbished dwellings). sums non-auxiliary ooled dwelling ontribution above (6) with 4% ontribution as above (9). In newbuild taken as 95% gross ooling demand and in refurbishment 8% (taken for all new and refurbished dwellings between 2 and 21). 4.4 Non-domesti nergy Due to the availability of far less data than in the domesti setor in all ountries, the alulation method was strongly influened by available data (prinipally from urostats) and relied on interpretation of other information obtained in various ountries but whih ould not be obtained on (25)

28 a omprehensive basis. Basi data used for all ountries were: total non-domesti energy used (1986); energy use growth foreasts and eonomi growth foreasts. The approah is therefore very different from that used in the domesti setor. Only the energy use within the non-domesti setor that an be influened by passive solar design was onsidered. This is heating, lighting and auxiliary ooling. Within ooling only the refrigeration part has been onsidered despite the onsiderable energy used by fans for air movement in air-onditioned buildings and for mehanial ventilation. The reason for this stane is that whilst frequently both refrigeration and mehanial ventilation an be avoided by passive solar design, there are many situations where mehanial ventilation will be neessary (or anyway used) to avoid refrigeration, and thus the fan energy element of an aironditioning system may not be eliminated and may in pratie be inreased. 4.5 Non-domesti existing foreast, base ase, no inreased use of passive solar design. SCTION 1 Total energy used in the non-domesti setor ~ nergy used for heating DATA/CALCULATION The 199 and 2 figures are alulated from the 1986 data and the predited growth in energy onsumption. Total energy onsumption in 21 was kept at the 2 level to reflet both energy effiieny measures plus growth in usage. Breakdowns of non-domesti energy by use were used to alulate heating energy for 199, with figures for 2 and 21 alulated as above. Where no breakdown was available, estimates were made on the basis of similar ountries. SOURC urostat Review BR (UK) d nergy used for lighting As above to give (delivered) lighting energy onsumption. No allowane was made here for photo-eletri ontrol usage as this was onsidered as use of passive solar daylighting (see definitions setion 1.4). BR (UK) (26)

29 nergy used for ooling Unplanned solar ontributions to heating 199 UK estimates made on the basis of a survey of the proportion of offie spae with auxiliary ooling, the area of offie spae, typial annual ooling energy used (from survey data) and an estimate of the other uses of auxiliary ooling (in stores, banks, restaurants, hotels, onferene entres, et). stimates for 2 and 21 made on the basis of newbuild and major refurbishment rates (both 2% of 199 floor areas) and proportions with auxiliary ooling. Cooling estimates were provided for two other ountries, Italy and Portugal, and these three ountries, together with typial ooling energy onsumption were used to interpolate estimates for other ountries taking into aount latitude, level of development, eonomi growth rates, et. d on estimates of solar ontributions as a perentage of gross heating loads (varying from 1-15%) derived fators were applied to the auxiliary heating loads to give unplanned solar ontributions. BSRIA (UK) BR (UK) RIBA Kasabov CC Buildings 2 Projet Monitor Q Unplanned solar ontributions to daylighting No unplanned daylighting ontributions were inluded (see definitions setion 1. 4) I (27)

30 2 Unplanned solar ontributions to ooling No ontributions were assumed for the ountries in northern latitudes as there is thought to be little or no design in buildings to redue ooling loads. In the southern latitude ountries (Portugal, Spain, Italy and Greee) assumed that 5% of buildings without auxiliary ooling have a ooling load, of whih 5% is satisfied by passive solar design (remainder results in overheating). In Frane 1% of buildings have a ooling load. It is aepted that these figures are rude,estimates only. They are made to give a reasonable base for measuring hange. 4.6 Non-domesti passive solar foreast - tehnial Tehnial solar ontribution to heating Made up of three parts: - the unplanned ontribution from the existing stok, whih redues over time due to demolitions and refurbishment (3% pa stok redution); - the tehnial from newbuild (2% pa of 199 stok) average 3% solar ontribution to gross heating load (but this is a redued load ompared with 199 load), estimated equivalent to 2% of 199 heating load. Ireland and Denmark assumed lower values (18% and 15% respetively), Greee and Portugal assumed higher values (3%); - the tehnial from refurbishment (2% pa of 199 stok), assumed at 17% of 199 heating load (i.e. between existing and newbuild). Ireland and Denmark assumed lower rates (15%), Greee and Portugal assumed higher (2%). (28) Projet Monitor

31 ~ Tehnial solar ontribution to lighting 1 Tehnial solar ontribution to ooling 11 Total tehnial solar ontribution 4.7 Pollution ~ Pollution 199 ~ Pollution savings 2 J. Pollution savings 21 No ontributions to the (unhanged) existing stok was taken. 5% ontribution to both newbuild and refurbishment assumed from design (to inrease daylighting) and ontrols (to redue unneessary auxiliary lighting). Made up of two parts: - the unplanned solar ontribution as in 7 above; - for newbuild, assumed tehnial is to eliminate all ooling load and for refurbishment to redue the ooling load by 5%. Broken down into delivered eletri energy only (lighting and ooling) and heating energy saved. Also total primary energy equivalent saved due to tehnial solar ontributions. d on fuel split, inluding fuel used to generate eletriity, and pollutants arising from eah fuel, gives total weights of pollutants produed in 199. Inludes the effet of forthoming legislation on powerstation emissions. Gives savings in pollutants resulting from redued fossil (and nulear) fuel onsumption resulting from use of tehnial solar ontributions. Pollution redution for ooling ontribution taken only as substitution of auxiliary ooling by passive solar design (not total passive solar design ontribution). Calulated as year 2. BR Building 2 urisol (UK) UK nergy Stat istis SKA - letriity for Life (29)

32 5. RSULTS 5.1 nergy - urope wide Passive solar design at present (199) supplies the uropean Community with the equivalent of 96 mtoe (million tonnes of oil equivalent) (115 TWh) of primary energy per annum. This is 9% of the total fuel used in the uropean Community (figure 1), larger that the amount of oal diretly burnt for heating (6%). Compared with the use of fuels in the housing and non-domesti building setors (i.e. exluding industrial proess heat and transportation energy use) solar energy supplies 13% of the total (figure 2). The majority of the solar energy (78%) is used diretly to heat buildings with the remaining 22% arising from passive ooling design in ountries in southern latitudes. Thus it is lear that solar energy is aiready a very important fuel in urope. Over the next 2 years, the amount of solar energy used will hange depending on a number of fators. If no speifi ation is taken to promote the use of passive solar design, a small rise of 8% above the 199 levels is predited by the year 2 and a rise of 6% by the year 21. These hanges result mostly from an inrease in the number of buildings, but this is modified by inreased levels of fabri insulation. This effetively redues the solar utilisation, as the heating season and therefore the period when solar gain is useful is shortened when higher levels of insulation are used. However if ation is taken to inrease solar measures, the exists to greatly inrease the use of solar energy in buildings in the future. By the year 2 the overall amount ould be inreased by 27%, an inrease of 26 mtoe (313 TWh), and by 21 the amount ould inrease by 54% of the urrent level of utilisation, or 52 mtoe (62 TWh) per annum. Figure 3 shows the inrease in solar _ontribution in the 5 ategories, domesti heating, non-domesti heating, domesti ooling, non-domesti ooling and non-domesti lighting, for the whole of the uropean Community. These s are the maximum tehnially possible and inlude allowanes for buildings whih annot be oriented optimally et. In pratie the will be redued by suh fators as low take-up and poor design and operation. Whilst t he solar ontributions to heating are the largest, in absolute terms, the largest inrease is foreast in the use of daylighting in non-domesti (3)

33 buildings, an inrease of nearly 18 mtoe(22 TWh). The foreast inrease in solar heating in nondomesti buildings is also large at over 16 mtoe (19 TWh) per annum and reflets the relatively high rates of new onstrution and refurbishment in this setor ompared to housing. The use of passive solar design to redue ooling loads gives smaller total savings than that resulting from solar design to redued heating loads, but this is due to the small need for ooling within.urope as a whole. Within individual ountries the piture is very different, (setion 5.2). For example while Denmark, Ireland and the Netherlands have negligible ooling demand and therefore negligible passive solar ontribution to ooling, Greee, Spain, Italy and Portugal ahieve 5% of their tehnial solar ontribution through passive ooling design. Overall an inrease in domesti ooling solar ontribution of 9 mtoe (11 TWh) is possible by 2.1. The lower ontribution for the non-domesti setor ompared to the domesti setor, is due to the larger amount of housing in southern latitudes ompared to the amount of non-domesti buildings. The small inrease in the use of solar energy for heating houses, 2 mtoe (25 TWh) or a 4% inrease over 199 usage, is a result of assumed inreased levels of fabri insulation (resulting in redued absolute utilisation of solar gains), ombined with the very small newbuild and refurbishment rates for housing. Whilst greatly inreased solar.ontributions are possible in new houses and during refurbishment, it is the unhanged existing stok whih forms by far the largest part of the housing stok (for instane 8% by the year 21 for the UK). The low newbuild and refurbishment rate means that the large inrease in solar.ontribution from individual houses takes a very long time to affet the energy onsumption of the setion as a whole. This situation is exaerbated by.the assumption that insulation of the existing housing stok will take plae over the next 2 years reduing the utilisation of solar heating by 1%. One possible solution whih ould lead to a signifiant inrease in solar.utilisation in this setion is the development of new tehnologies whih ould be retrofitted to the existing housing stok on a large sale. Setion 6.2 disusses one idea urrently unqer development - transparent insulation. (31)

34 It is important to note that inreased solar ontributions from individual uses, when added together produe the signifiant overall inrease of 54%. 5.2 nergy - Individual Countries Figure 4 shows the solar-energy usage in the various ountries, and figure 5 the ountry populations for omparison. Figures 8-19 show the solar-energy usage in eah ountry together with the pollution savings Belgium. With a population of 1 million, Belgium's solar usage is urrently around 4% of the uropean total solar usage. In the year 21 solar heating aounts for 85% of the tehnial solar, with non-domesti ooling and lighting making up the rest. A 32% overall inrease is solar usage is possible by 21. Denmark. With 5 million population, Denmark ontributes 1% to the total uropean solar usage. The requirement for ooling in Denmark is negligible but a doubling in the use of solar heating in the non-domesti setor is thought (by Danish soures) to be possible by the year 21, ontributing to an overall inrease in solar usage of 79%. This high figure is due to the above average projetion for solar heating in the non-domesti setor. Frane. With a population of 55 million, Frane ontributes nearly 16% to the total solar usage. Solar heating makes by far the largest ontribution to the tehnial solar ontribution, 72%, ooling supplies 16% and lighting 12%. An overall inrease in solar usage of 42% is possible by 21. West Germany. With the largest population, 61 million, and the largest energy usage, Germany's solar usage is by far the highest in urope, above 25% of the total. Again solar heating dominates the tehnial solar ontribution in 21, 85%, with non-domesti ooling ontributing only 2.5% (due to the lak of ooling demand). Nevertheless, due to the large size of the German energy use, this ooling ontributing is nearly 8% of the total nondomesti ooling. An overall inrease in solar ontribution of 38% is possible in Germany by 21. Greee. Population 5 million, with a solar ontribution of less than 2.5% of the uropean total in 199. Solar design ooling ontributions dominate here, 55% at present. Overall, an inrease in solar usage of 87% is thought possible by the year 21. The large inrease is due to the {32)

35 for passive design to redue ooling loads Ireland. With the seond smallest population in urope, 3.5 million, Ireland has a solar ontribution of less than 1% of the total. No ooling loads have been inluded and the nondomesti setor provides the majority of the inrease in solar usage, nearly 7% aording to loal experts. By 21, overall solar usage ould be inreased by nearly 7%. Italy. With one of the highest populations in the C, 57 million, Italy's solar ontribution is seond highest at 18% of the uropean total. Solar design ooling ontributions ould provide more than 53% of the total by 21, an inrease in usage of 64% over the 199 figure. An overall inrease in solar ontribution of 71% is possible by 21. Luxembourg. The smallest ountry with a population of 37,, naturally only ontributes a small part.3% of the total solar usage. Non-domesti heating provides by far the largest solar ontribution, 58% by 21. A 74% overall inrease in solar ontribution is possible by 21 due to the large size of the non-domesti setor ompared to the housing setor. Netherlands. With a population of 14.5 million, the Netherlands ontribute 3.5% to solar usage. Cooling energy use is very small, non-domesti heating ontributes nearly half the solar energy use by 21. An overall inrease in solar usage by 21 of 65% is possible. Portugal.With a population of 1 million, Portugal urrently ontributes under 3% to the total solar usage. Domesti ooling is ly the largest single usage of solar design, 45% of the total by 21 is possible. Overall, solar usage ould inrease by 76% in 21. Spain. Population 38.5 million, Spain ontributes 12.5% of the total solar usage in 199. Cooling ontributes nearly 5% of the energy savings by 21 with non-domesti lighting ontributing 11.5%. A 73% inrease in solar usage from 199 to 21 is possible. United Kingdom million population ontributes 13% of total solar usage in 199. Cooling energy is small relative to heating and this ontributes to the low possible inrease in overall solar usage by 21 of 45%. (33)

36 Whilst the largest absolute solar usage figures ome from the ountries with the largest populations, the greatest relative inreases in solar usage are likely to ome from ountries in southern latitudes, where solar ontributions to heating, lighting and ooling an be inreased. This demonstrates that a poliy to inrease usage of solar design, to redue onsumption of fossil fuel, should not onentrate on any one setor, nor ountries in northern or southern latitudes only, but should spread aross all setors, throughout urope. 5.3 Pollution redution urope. Figures 6 and 7 show the pollution savings ar1s1ng from the use of passive solar design throughout urope. At present passive solar design is saving 229 million tonnes of C 2 per annum a redution of nearly 17% in the C 2 whih would be produed in the absene of solar ontribution. 1.3 million tonnes of so 2 and.56 million tonnes of NOx (Oxides of Nitrogen) are also being saved by solar gain. If the tehnial solar ontributions determined in this study were ahieved, the amount of C 2 saved per annum by the year 21 would inrease to 332 million tonnes, an inrease of 45%. The annual redution in C 2 prodution below 199 levels due to solar design ould be 43 million tonnes by the year 2 and 13 million tonnes by the year 21. The savings in so 2 and NOx derease in the future due to implementation of legislation to redue emissions of these gases from power stations. These will not be disussed further in this report sine the effet of the legislation greatly outweighs the solar effet. If targets for redution in emissions are met, the problems assoiated with emissions of so 2 and NOx (prinipally "aid rain") will be thus greatly redued. The possible redution in nulear waste obviously reflets the use of nulear power within a ountry, together with overall fuel use redution. At present (199), solar energy redues nulear waste by more than 18% from what would be produed without the solar ontribution. Seven ountries use nulear power but Frane dominates and ontributes around 7% of the 199 savings and 57% of the 21 savings. Overall, solar design ould inrease savings in nulear waste by around 7% by 211. (34)

37 5.3.2 ountry analysis. Figures 8-19 show the pollution savings for eah ountry. Three ountries, Germany Italy and the UK, urrently ontribute two thirds of the savings in C 2 due to solar design. Frane ontributes only 9% to the savings due to its large nulear energy setor. The piture is broadly unhanged by 21, if the tehnial is ahieved. The inrease in savings in C 2 pollution possible by 21, varies greatly between ountries, from 19% in Belgium to 14% in Greee. The variations roughly reflet the hanges in solar ontributions, with the ountries in southern latitudes thus showing the higher perentage savings. The use of non-fossil fuels (mostly nulear generated eletriity) also affet the possible C 2 redution. (35)

38 6 CONCLUSIONS 6.1 Ahievement of the "tehnial " The energy and pollution savings disussed in the previous setion for 21 are derived from the tehnial solar ontributions as desribed in setion 1.5. Setions 3.3 and 3.4 disuss the fators whih will affet the ahievement of this tehnial. Assessment of the level of ahievement that are likely or possible is virtually impossible. Many of the fators are under the ontrol (at least partially) of governments and thus a high level of ahievement is theoretially possible if the politial will exists. If for example the redution of the "greenhouse effet" beame a poliy priority within the C, legislation by itself ould be used to ahieve virtually all the tehnial solar ontribution and onsequent redution of C 2 prodution. On the other hand without any legislation or inentives to inrease solar energy usage, even assuming the promotion of passive solar design within eduation and generally outside, ahievement of more than 25% of the tehnial seems most unlikely. If fuel pries rise dramatially as has happened in the past and as is possible within the next 1 years, uptake of passive solar design, together with other energy saving tehniques, ould be high without legislation or other inentives. Unfortunately sine large individual solar ontributions an only be ahieved in new or onverted buildings using solar design priniples, the low newbuild and refurbishment rates generally, mean that the overall savings are only built up over a number of years. If solar design is not widely adopted before the year 2, only a small part of the tehnial will be ahieved by New Tehnology Development of new tehnologies whih are appliable to existing buildings are a means of further inreasing solar usage. The work on transparent insulation is a step in the right diretion. One alulation arried out as part of this study indiates that replaement of half of all glazing in all housing by transparent insulation ould alone save 28 mtoe (342 TWh) of heating energy per year. This is equivalent to inreasing by 5% the total solar energy used for heating houses in the 21 tehnial senario. Clearly this is not an ahievable target but indiates the of (36)

39 applying passive solar measures to the existing housing stok. 6.3 Where effort should be put The total tehnial solar energy apable of being utilised in 21 is made up of the five setors. Taken individually these.ontributions are not all large, but together the savings are signifiant. ffort should therefore be put into eah setor to maximise ahievement of this Domesti heating. The inrease in use of solar energy is limited by the unhanged housing stok,.whih under normal onditions reeives no major attention for periods of up to 5 years. Thus, whilst stimulation of passive solar design for new and refurbished houses is neessary, development of new tehnologies suh as transparent insulation, and methods of implementation to apply to the existing housing stok is required if a major inrease in solar ontribution is to be ahieved in this setor Non-domesti heating. Greater for inreasing solar utilisation is available here due to higher newbuild and refurbishment rates. duation of arhitets and other designers in solar design should be effetive as should the demonstration of ost effetive solar measures. Development and use for transparent insulation ould have an even greater effet in this setor than in the housing setor Domesti Cooling. Promotion and eduation for solar design to avoid overheating and the onsequent demand for auxiliary ooling is very important. The tehniques and produts are readily available in ountries whih have a domesti ooling load but validated and user friendly design tools are needed to design and to demonstrate the effetiveness of solar design. There is a need to integrate solar design for heating and ooling in southern latitudes so that neither is ompromised by the other Non-domesti oo1inq. Large benefits are available in.this setor sine there is a general move towards an inrease in the use of air onditioning in many non-domesti buildings. Sine naturally ventilated and ooled buildings have many advantages over air onditioned buildings other than redued energy onsumption (see setion 1.7), promotion of tnese onepts is important. Solar design priniples and tools are available though these are not generally (37)

40 6.3.6 applied. Legislation is used in Denmark to avoid air onditioning in new offies. Non-domesti lighting. Large savings are possible in this setor in all ountries from both lighting ontrols and daylighting design. duation and promotion of both the priniples and design tools is needed. A large part of the tehnial should be ahievable in this setor. (38)

41 Total fuel use in the uropean Community 199 {inludes transport and industrial proess use) FIGUR 1 9% Solar energy (primary fuel equivalent) 6% Solid fuel (diretly burnt) 15% Gas (diretly burnt) 37o/o Fuel (primary) for eletriity generation 33% Oil (diretly used) Fuel use in housing and non-domesti buildings - in the uropean Community 199 (exludes transport and industrial proess use) FIGUR 2 13% Solar energy (primary fuel equivalent) 6% Solid fuel (diretly burnt) 18o/o Gas (diretly burnt) 43o/o Fuel (primary) '-"IIIIIIIJ for eletriity generation 2% Oil (diretly used) 39