TL: UNLOCKING THE POWER OF OUR CITIES SOLAR POWER AND COMMERCIAL BUILDINGS A GREENPEACE REPORT SO: GREENPEACE UK, (GP) DT: JUNE, 1997 TABLE OF CONTENTS Executive summary Introduction The environmental costs of electricity generation Energy and buildings Britain's large solar resource Matching supply and demand Market opportunities and industry support A new design tool for architects The benefits of solar powered buildings Compatibility of materials Tenants, owners and developers The cost of solar powered buildings Case studies of existing solar powered buildings * Britains first solar powered office * Solar facade in Germany * Semi-transparent solar facade * Solar public library * Solar skylighting Information on solar photovoltaics Planning criteria for architects and building engineers Solar suppliers and contacts References EXECUTIVE SUMMARY The world is under threat from the greenhouse gases, principally carbon dioxide, which lead to climate change. The insurance industry has already suffered financial losses due to extreme weather events which are the first ‘fingerprints’ of disruption of the climate. Fossil fuelled power stations, which generate most of the UK’s electricity, are a major source of CO2. Energy use in buildings accounts for 50% of the UK’s CO2 emissions, and this is set to increase by 10-15% within five years. A switch to renewable energy sources and increased energy efficiency is needed to combat climate change. Solar photovoltaic power converts sunlight directly into clean electricity, and is a simple, reliable and commercially proven technology. Solar photovoltaics is the only electricity generating renewable technology that can be mass deployed in the urban environment. Two thirds of the UK’s current electricity production could be generated by solar photovoltaics if it were deployed wholesale in homes and offices. Solar photovoltaics can be substituted for existing building materials such as facades, glass roofing, parapets and glazed stairwells, and incorporated into new or existing buildings. Any area of a building which is exposed to the sun is suitable for solar photovoltaics. Because most demand for electricity in a commercial building electricity is 9am and 5pm, there is an excellent correlation between the electricity produced by solar photovoltaics and the demand of a commercial building. A typical solar facade could generate around 30% of the annual electricity requirements of a commercial building. Solar powered buildings are usually connected to the electricity grid so that surplus solar electricity can be exported and any deficit in supply can be imported from the grid. Solar powered buildings have been in existence in continental Europe for more than a decade, for such uses as schools, universities, office headquarters, hotels, factories, libraries, railway stations, and government and municipal offices. A huge market opportunity exists for solar photovoltaics in the UK, where two million square metres of new commercial and industrial roofing are built each year. In Europe, the market for solar powered buildings has expanded rapidly and is now worth £5 million. Major building and engineering companies are selling and installing solar photovoltaics as an ‘off the shelf’ product today. Solar photovoltaics offer architects new possibilities for creative design at the cutting edge of clean energy technology. For property developers, owners or tenants of commercial buildings, solar photovoltaics make a clear statement of environmental commitment, and offer savings in the long term. The price of solar photovoltaics is roughly equivalent to that of expensive cladding materials, such as marble. However, when compared to more conventional cladding materials such as glass or steel, installing solar photovoltaics adds only 2-5% to total construction costs of the building. This additional cost is partly offset by savings in the purchase of electricity. The UK’s first solar powered building came into operation in 1995, yet industry and Government have largely ignored the benefits. This report provides details of the first UK solar building, and looks at four well-established solar photovoltaic buildings in continental Europe. An exciting opportunity exists to transform buildings into a central solution to climate change. Greenpeace has identified commercial buildings as a key launch-pad for solar technology in the UK. INTRODUCTION The domination of large fossil fuelled power stations in the UK’s electricity supply is contributing to pollution of the world’s atmosphere and the threat of climate change. Our urban areas and the buildings we inhabit are a major cause of the problem. In the United Kingdom buildings produce, as a by-product of the energy they consume, some 50 per cent of total carbon dioxide. The Intergovernmental Panel on Climate Change (IPCC), which provides scientific advice to governments, has stated that 60-80 per cent cuts in greenhouse gases are needed if we are to avert the worst effects of climate change. In other words, to protect the world’s climate, we need a drastic reduction in our consumption of fossil fuels and a switch to renewable energy sources. One of the most exciting renewable technologies is solar photovoltaic power. Photovoltaic cells convert sunlight directly into electricity. The technology is simple, dependable and safe: it requires no moving parts or fuel, it is silent in operation and it generates pollution free electricity. Solar photovoltaic power is the only electricity generating renewable technology that can be used in the urban environment at the point where the majority of electricity is consumed. It is an innovative technology which has captured the imagination of the public. Solar photovoltaic power is a solution which can be deployed at the heart of the problem. Despite its availability and advantages, solar photovoltaic power has been virtually ignored in the UK. Yet the option of transforming offices and cities into suppliers of clean electricity is feasible, sensible and available now. Greenpeace campaigns for solutions to environmental problems and has identified commercial buildings as a key opportunity for developing solar technology in the UK. This report outlines the technical, aesthetic and environmental case for solar photovoltaic deployment on commercial buildings. If the different sectors of the building industry – architects, planners, engineers, owner and occupiers – adopt a positive attitude towards it, solar photovoltaic power can unlock the enormous energy potential of British buildings and create a new environmental aesthetic. Do you want to take part in the solar revolution? THE ENVIRONMENTAL COST OF ELECTRICITY GENERATION The 1980s and 1990s have been the hottest decades since reliable records began. The global average temperature is now half a degree higher than in the mid-nineteenth century. The regional effects of such change are dramatic. Mountain glaciers are retreating, and a break-up of sea ice has been observed at the north and south poles. Rapid changes in sea temperature in warmer parts of the world’s oceans have disturbed marine ecosystems and caused mass die-off of coral reefs. In the words of the UK Meteorological Office ‘there is clear observational evidence of…global-scale warming in this century’ and ‘anthropogenic emissions of greenhouse gases have been, and will increasingly be, a significant contributing factor’1. In the UK, most electricity is still generated hundreds of miles from the homes and offices which require it, by old coal-fired stations using combustion technology developed in the 1950s. It is a dirty and wasteful process, and as a result the electricity supply industry is the largest source of greenhouse gases in the UK. Every unit of electricity consumed in the UK commits us further to climate change, and to an ensuing rise in extreme weather events. The insurance industry has already had to pick up the bill for a steep rise in damage from extreme weather events. A spokesman for the UK insurers General Accident said that the ‘huge increase in weather-related losses should be attributed to lasting changes in weather patterns and not to a run of bad luck’2. In 1993, Munich Re, the world’s largest reinsurer, called on governments, businesses and insurers alike to ‘take immediate action’ to address the ‘dramatic development of natural catastrophes...the threatened climatic changes demand urgent and drastic measures’. The nuclear industry, once hailed as the answer to all our energy needs, has created its own set of insurmountable problems. There is no safe way to dispose of nuclear waste, and unacceptable risks are posed by radioactive discharges, the potential for nuclear accidents and the spread of nuclear bomb making materials. ENERGY AND BUILDINGS Domestic and commercial buildings account for fifty per cent of the UK’s total emissions of the main greenhouse gas, carbon dioxide (CO2). This represented over 275 million tonnes of CO2 in 1993 3,4. The trend for the increasing use of computers and the over-use of air conditioning is a problem. Studies done for the Department of Trade and Industry show that electricity use in buildings is likely to be ten to fifteen per cent higher in the year 2000 than in 1990 5. These figures are more alarming when urban areas are examined. The commercial sector uses 25 per cent of London’s energy and is responsible for thirty per cent of the capital’s CO2 emissions. In parts of central London commercial energy use is equivalent to an annual consumption of 33,000 tonnes of coal per square kilometre 6. The desire to reduce the impacts of such intense energy use has led many architects and building developers to use a variety of energy efficient building techniques such as the incorporation of passive solar design and natural ventilation. The trend for greener buildings is increasing, and 25 per cent of new buildings7 are classified under the BREEAM environmental rating. As the only electricity generating renewable technology that can be deployed directly in the urban environment, solar photovoltaic power offers architects and the building industry an opportunity to go one stage further in the design of low energy buildings by using solar energy to create a supply of clean, climate-friendly electricity. Every square metre of solar photovoltaics installed on a building in the UK will, in its lifetime, displace one tonne of carbon dioxide. BRITAIN'S LARGE SOLAR RESOURCE [FIGURE NOT AVAILABLE: UK solar energy resource map-annual average solar energy (kWh/m2/day] Despite Britain's cloudy weather, there is a rich solar resource available. The solar energy that falls on the UK every year is equivalent to more than seven hundred times the nation’s electricity consumption. Studies conducted for the Department of Trade and Industry have shown that if solar photovoltaics were deployed wholesale today on homes and offices , they could generate two thirds of the UK’s current electricity production each year8. If photovoltaics were deployed on the available surfaces of commercial buildings, eight per cent of the UK’s electricity could be supplied. With the future development of even more efficient photovoltaic cells, solar power has the potential to generate more electricity than we currently generate and consume today in the UK. MATCHING SUPPLY AND DEMAND Since the majority of electricity in commercial buildings is used between the hours of 9am and 5pm there is an excellent correlation between the electricity supplied by a solar facade and the building’s overall demand for electricity. As a result, eighty to ninety per cent of the electricity generated by solar photovoltaics can be used directly within a building to power computers, lights etc 9. Solar buildings in Europe are usually connected to the electricity grid to allow any surplus electricity generated by photovoltaics to be exported for use by other consumers. Grid connection also means that electricity can be imported when necessary, to meet additional electricity needs which cannot be met by solar photovoltaics. Maximising the energy efficiency of a commercial building will increase the proportion of electricity that can be provided by solar photovoltaics. The percentage of a commercial building’s electricity demand which can be met by solar photovoltaics obviously varies according to the amount installed and the time of year. However, over the course of a year, a typical solar photovoltaic installation could generate roughly thirty per cent of the annual electricity requirements of a commercial building. In the UK it is possible to generate 75 units of electricity per year from each installed square metre of solar facade vertically deployed in a due south orientation and assuming no shading10. Electricity output increases to around 100kWh per square metre if the solar application is tilted at the optimum 30° tilt angle. A vertical solar facade orientated in a due west or due east direction would generate around fifty per cent of the output of a facade facing due south. MARKET OPPORTUNITIES AND INDUSTRY SUPPORT The commercial building sector represents a significant potential market for solar photovoltaics in the UK. Two million square metres of new commercial and industrial roofing is built in the UK each year and current available roof space on commercial buildings is estimated to be 240 million square metres 11. In mainland Europe, principally in Germany and Switzerland, after only a few years the market for solar photovoltaics on commercial buildings has risen to five thousand square metres per year and is worth five million pounds 12. The current market opportunities for expansion have attracted major building industry players to invest in the supply and installation of solar photovoltaics, including the international consulting engineers Ove Arup and Partners; Schüco, a major supplier of facades; and Flagsol, a subsidiary of the major UK glass supplier Pilkingtons. A NEW DESIGN TOOL FOR ARCHITECTS Until recently there has been no straightforward way for architects to design buildings which generate a sizeable proportion of their electricity from renewable energy sources. Solar photovoltaic power offers architects this option, and their professional skills are needed to develop intelligent, innovative and aesthetically pleasing designs incorporating solar photovoltaics. There are many opportunities for creative design and imaginative thinking as photovoltaics can be applied to so many parts of a building’s external structure. Nearly seventy per cent of a sample of recently polled architects indicated that they would consider installing solar photovoltaics in the design of a new low energy building 13. BENEFITS OF SOLAR POWERED BUILDINGS Solar photovoltaics can be incorporated into new constructions at relatively small additional cost. They can also be installed on existing buildings during refurbishment. For the architect, solar photovoltaics represent an exciting opportunity for aesthetic and environmental innovation. For the developers, owners and occupiers of commercial buildings, the installation of solar panels ensures reduced impact on the environment, reduced electricity costs and a clear corporate message about commitment to environmental solutions. COMPATABILITY OF MATERIALS Solar photovoltaics are a practical solution for the building industry because they can be substituted for many existing materials already commonly used on the outside of a building. Most modern commercial buildings have an outer skin, or facade, which is distinct from the load bearing structure of the building. This facade is usually made of glass, brick, stone, or metal, depending upon aesthetic and cost considerations. As well as providing a strong visual identity to a building, the facade also protects it from the elements. While the examples in this report focus predominantly on facades, solar photovoltaics can be integrated into all aspects of the external body envelope such as atrium glazing, glass domes, sunshades and rooflights. When deployed on commercial buildings solar photovoltaics perform in the same way as a conventional building material, such as glass or metal, ensuring weather protection. However, unlike these passive materials, solar photovoltaics also serve the function of generating clean electricity for use within the building. All areas of a building which are exposed to the sun are suitable for solar photovoltaics. The following areas can be used: parapets, glazed stairwells, entrances (steel and glass constructions), attics, skylights in hallways and glass roofing in shopping centres, galleries and all kinds of inclined roofs. Photovoltaic modules can be incorporated into an existing building during refurbishment, and can be custom made for any use. TENANTS, OWNERS AND DEVELOPERS Incorporating solar power into the external skin of new buildings enables property developers to build prestige developments which make a strong environmental statement. Such ‘cutting edge’ buildings are likely to be in more demand as the environmental concern of occupiers increases. For the owner or tenant of a commercial building, specifying a solar powered building offers the immediate opportunity to make a visible commitment to environmental solutions. Solar photovoltaics also enable tenants to reduce electricity bills and safeguard against possible increases in electricity prices. For the large financial institutions, such as insurance companies and pension funds, which invest wholesale in the commercial property market, solar powered buildings offer an immediate positive investment in a solution to climate change. THE COST OF SOLAR POWER BUILDINGS Solar facades are equivalent in cost to expensive cladding materials such as polished stone. Ove Arup has calculated however, that when compared to more conventional cladding materials such as glass or steel, installing solar photovoltaics adds only a marginal extra cost, some 2-5%, to the total construction costs of a commercial building 14. The savings in electricity bills go some way to ameliorating the initial costs. The total cost of a solar facade incorporates several components: photovoltaic panels, the cladding system and the electrical wiring and inverter costs. Production costs of solar panels are normally presented in pounds per watt. The UK’s first solar powered office block is a building at the University of Northumbria in Newcastle. Based on the experience of this project, the purchase price of solar panels is £4.10 per watt. On average it is possible to install around 100 watts of solar panels per square metre of solar facade. The total cost of the Newcastle solar facade, including electrical and installation costs, has been calculated at £900 per square metre of facade 15. It should also be noted that each square metre of a solar facade can generate around 1,800 units of electricity over its 25 year lifetime. Therefore, each square metre of solar application will in its lifetime avoid the purchase of around £70 of electricity at current prices. Click on the diagram above to see the cost of solar facades, compared to conventional passive building materials. The diagram presents an overall comparison of the total costs of a curtain facade, assuming (as is usual)that a structural frame already exists. CASE STUDIES OF EXISTING SOLAR BUIDINGS In the UK, both industry and the Government have ignored the benefits of photovoltaics and there is only one major solar building in existence. However, solar powered buildings have existed for years in continental Europe, for such diverse uses as schools, universities, office headquarters, hotels, factories, libraries, railway stations and government and municipal offices. The first European solar building was constructed in Germany in 1983. Detailed on the following pages are just a few examples of photovoltaics in operation. BRITAIN'S FIRST SOLAR POWERED OFFICE The Northumberland building, a typical 1960's office block, needed refurbishment because the existing pre-cast concrete cladding was failing. It was fitted with a new solar facade, an integral photovoltaic cladding system which is one of the largest in Europe. This was completed in January 1995 and will provide fifty per cent of the building's electricity requirements in the summer and ten per cent in the winter. Over a year the facade will generate thirty thousand units of electricity, equivalent to thirty per cent of the building’s annual electricity needs 16. The facade will produce CO2-free electricity over the course of its twenty-five to thirty year lifetime, saving the emission of one thousand tonnes of the gas 17. It will generate electricity that would normally have cost 30,000 [pounds] at today's prices. The solar cladding has been installed on the south side of the building and inclined at 25 degrees to the vertical, maximising the winter sun output. Other methods of incorporating solar photovoltaics include curtain walling, as sunshades and as a roofing material. The following case studies provide dynamic examples of these applications. SOLAR FACADE IN GERMANY In 1993, Flachglas, the German solar facade supplier, installed a solar facade on its building at Wernberg in Germany. The total facade area of building is 217 square metres, of which 140 square metres has been clad with solar photovoltaics. 85 square metres of solar panels have been installed on the south west side of the building and a further 55 square metres on south east. The architect decided to install ‘false’ solar panels on the west side of the building to ensure aesthetic continuity. The facade is fully grid connected and has a power output of 10kW, enabling it to generate 7,000 kWh of electricity per year. In 1994 the building was awarded the prize of `Best Architecturally Integrated Solar Building'. SEMI-TRANSPARENT SOLAR FACADE In 1993 a local authority administration building required renovation. The architect was asked to design a new glass entrance to the building. The new south east facing glass entrance was designed to incorporate twenty four solar panels angled at a 54°[degree] incline. The thirty square metres of solar panels generate around 2,000 units of electricity per year. The architect designed the solar facade to enable light to pass through the facade, thus ensuring adequate natural lighting in the winter months as well as using the solar panels to help reduce overheating in the summer months. SOLAR PUBLIC LIBRARY The new Mataró-Barcelona public library provides an excellent example of an integrated curtain wall solar facade. The library has a total installed capacity of 53kW of solar power. Some 240m2 of semi-transparent polycrystalline solar photovoltaics have been deployed as a curtain wall. By using a semi-transparent solar facade natural daylight passes into the building and occupiers and users of the building are able to see through the solar facade to the outside. A further 400m2 of crystalline silicon solar photovoltaics have been integrated into the roof of the library. The building will be connected to the local grid of the Spanish utility ENIIER. A further innovation has been the integration of solar thermal design into the facade. Air passes behind the solar facade where it is heated and can then flow back into the building and will contribute to the heating demand of the library. This solar-thermal system also acts to cool the photovoltaic facade; thus maximising the electricity production of the solar cells. SOLAR SKYLIGHTING This solar project is an excellent example of the application of solar power for skylighting features. The administrative office of the city of Halle installed a thirty metre long skylight incorporating 28 solar panels located above a hallway. The architect’s brief was to produce a feature which utilised solar power while at the same time providing adequate natural lighting of the hallway below. Because of the degree of inclination possible with skylighting features, the potential electricity output can be maximised. In order to ensure adequate lighting below, each skylight section was divided into three with the solar photovoltaics being deployed above and below insulating glass. The solar application also helps to prevent overheating of the hallway in the summer. The solar skylight generates 2,500 units of electricity each year. Information about the electrical system converting the solar power to mains power is provided for the occupiers and visitors to the building. INFORMATION ON SOLAR PHOTOVOLTAICS What are solar photovoltaics? Solar photovoltaics enable sunlight to be transformed directly into electrical power. This transformation is made by the photovoltaic effect, or interaction between radiating sunlight and the semiconductor material of the solar cell. This generates electrical charges which are conducted away by metal contacts. The direct current produced can be transformed into alternating current suitable for the grid by connecting a AC/DC inverter. The most important element of a photovoltaic generator is the solar or photovoltaic cell. Several solar cells are combined in series or parallel into an electrical unit, the solar module. How does a solar cell function? A solar cell consists of a very thin layer of semiconductor material (usually silicon). This is doped with impurities (other elements) on both sides. As a result one side acquires a negative charge (a surplus of electrons) and the other a positive charge (electron deficiency). When sunlight falls on the material which has been changed in this way, electrons are forced from one side to the other by its radiative energy. This produces electrical voltage, and thus direct current at the terminals. What is a solar cell made of? The basic material of the solar cell is silicon (Si), which is extracted from silica sand. Silicon cells can be divided into two main groups depending on how they have been processed: 1. Crystalline silicon cells. These are formed as single or multicrystal cells, and offer a high efficiency: fourteen to eighteen per cent. Crystalline silicon cells are used in cladding materials, roofs, skylights etc. 2. Amorphous silicon cells. Amorphous silicon solar cells are relatively inexpensive, and used in consumer applications such as watches and pocket calculators as well as buildings. Efficiency is five to eight percent. # Current status of photovoltaic technology Single crystal silicon cells currently have the greatest market share. These cells have been on the market for some years and the technology is fully developed. Companies in Germany, the USA and Japan are now working on developing the material and on new casting and crystallizing processes which would lower production costs. Work is also going on worldwide to achieve higher efficiency rates. Ribbon silicon: the biggest cost factor in the production of silicon wafers is the slicing. One option is to grow silicon in ribbons. However, only one company is currently working on this technology. Thin film silicon: besides the ribbon technique, which produces independent silicon ribbons, another possibility is the diffusion of silicon onto a substrate. The diffusion may be from a solution or gas. The production of all solar cells will have some environmental costs, all of which are many times lower than existing power production. However, Greenpeace cannot encourage the use of solar cells which incorporate heavy metals, and we would encourage consumers to use silicon cells. Amorphous silicon (a-Si) solar cells: there is a stable market for amorphous silicon cells in such things as pocket calculators and watches, minimal energy consumers. In supplying power in the kW range, amorphous silicon is still not often used on account of its low efficiency (5-7%) and its degradation (its efficiency falls in the first few years of operation). However, its use as a cladding component for large areas is being explored particularly in applications where its semi-transparent nature is useful. PLANNING CRITERIA FOR ARCHITECTS AND BUILDING ENGINEERS Installing photovoltaic modules Photovoltaic modules must be installed so that they are exposed to the maximum amount of light. The shade of surrounding buildings, trees or the building itself, has to be avoided to maximise power production. Photovoltaic facades in the UK are optimally installed facing south or south-west. Although an optimal 30°[degree] angle of inclination is almost impossible to achieve with normal facades, it can easily be achieved in rooflights and sun shades. There are basically four different kinds of facades and photovoltaic modules can be easily integrated into all of them. Cold facades. A cold facade is a bracket-mounted facade in which all parts of its construction have no thermal insulation. There is no connection to the building’s warm area. The warm area is contained within the thermally insulated surfaces of the building. Cold facades are weather protected, usually by single glazed safety glass. Photovoltaic modules can simply take the place of the safety glass. Parapets are one example of a facade’s cold area. Rain screen cladding (as at Newcastle) is another. Warm facades. These are facades which provide the functions of weather and noise protection and thermal insulation. The elements that can be used in them are either insulating panels, double-glazed windows or PV elements mounted in a proprietary facade structure. Modules can be designed to replace ordinary panels; alternatively, standard window-frame casements can used to support the modules. Cold-warm facades. Here, there is an exchange between cold and warm areas across the facade’s gradient. The warm areas are insulated by double glazed windows and other thermal insulation. Rooflight and glazed roof constructions. Photovoltaic modules made of semi- transparent amorphous silicon and crystalline modules with transparent interspaces can be used in those areas of the building shell where daylight is desired. Construction options For a photovoltaic facade to function reliably and efficiently in the long term, various requirements have to be met concerning the integration of the module, drainage, vapour pressure equalisation, cable layout, and design. The most important constructional elements here are the sectional frames used. These must: – bear the modules without stressing the modules; – be storm-resistant; – incorporate all cables; – drain off rainwater and condensation; and – create easy access to the module and its electrical system – deliver thermal and acoustic properties. The photovoltaic modules must be positioned to ensure good passive ventilation to ensure a minimum possible operating temperature – for crystalline silicon modules the lower the temperature the higher the efficiency. One possible facade construction is where the PV modules are secured in mullion – transom construction. The uprights (the vertical sections) are continuous and the crosspieces (the horizontal sections) made to fit. Highly elastic plastic seals are fitted between the PV module and the frame so that the module does not come into direct contact with metal. Electrical systems and components Coupling photovoltaic systems with the public grid is considered to have the biggest future in Europe. With these systems the photovoltaic power supply operates in parallel to the normal electricity supply to the building. In other words the building is connected to both the PV system and the mains and can use power from either source as required. If there is insufficient solar power to supply all the building needs the remainder is supplied by the mains. If there is excess solar power it may be exported to the mains. All these functions are automatic with the building occupiers unaware of any changeovers. Installations linked to the grid have significant advantages over other approaches, namely: the highest energy yield the lowest system costs the simplest technology standard components can be used high correlation between production and consumption security of supply through link with grid. A standard mains connected PV system consists of a photovoltaic array, a power conditioner, an inverter and control and protection equipment and any metering required. The power conditioner, comprising an inverter with control and protection equipment is required to convert the direct current electricity generated by the PV array into alternating current for use within the building. At the same time it must ensure the quality of the power output and its synchronisation with the grid. Surplus electricity is fed via a supply meter into the public grid. If more power is needed than the solar facade can provide, it is taken from the grid and measured by a second meter. Planning Criteria for Technical Installation Photovoltaic power plant facades should be planned and installed by electricians or consulting engineers. They have to adhere to the usual technical standards for any electricity generating system to be connected to the electric grid. The size of the photovoltaic facade will depend on the amount of energy needed and the suitable space available. Unnecessary costs are incurred if the installation is too large or too small. Economic benefits are at an optimum when almost all the daytime power requirements of the building are supplied by the solar facade. In general the construction of a new industrial or commercial building, or the extensive refurbishment of an existing building is likely to require planning permission from the local planning authority. Evidence of new buildings in the last decade suggest a wide latitude will normally be allowed to designers to choose the external appearance. Particular exceptions are buildings in conservation areas or other sensitive sites. Therefore, a well designed building that includes photovoltaics should be acceptable on planning grounds. The Department of Environment has published Planning Policy Guidance Note (PPG) 22 which covers solar installations. Regulatory Issues Government reports on grid connected PV establish that existing standards, codes and engineering recommendations are adequate for the application of photovoltaic system design and installation. The standards applicable in the UK are increasingly being harmonised with European and international standards such as ISO and IEC. The DTI states that the wealth of experience in other countries can be adapted to suit the UK situation18. Suppliers of photovoltaic equipment are familiar with the relevant codes and standards. Connection There is no statutory obligation for the Regional Electricity Company to connect and purchase power from a photovoltaic building, although many other utilities in the OECD countries facilitate connection as a matter of routine. However, individual building projects are likely to be accepted given that the first two major solar photovoltaic buildings in the UK were given support from the utilities concerned. Greenpeace is working to ensure that REC's are more receptive to building integrated photovoltaics. SUPPLIERS AND SOLAR CONTACTS Atlantis Energy Ltd Solar facade designers and engineers Lindenrain 4, 3012 Bern Switzerland Contact: Mr Posnansky Tel: +41 31 300 32 80 Fax: +41 31 300 32 90 BP Solar International Manufacturers of photovoltaic panels PO Box 191 Chertsey Road Sunbury-on-Thames Middlesex TW16 7XA Contact: Rod Scott Tel: 01932 779543 Fax: 01932 762533 British Photovoltaic Association Information on solar power in UK Contact Jenny Gregory at IT Power address Colt International Ltd Solar sunshade manufacturers and suppliers New Lane, Havant Hants PO9 2LY Contact: Nick Brown Tel: 01705 451111 Fax: 01705 454220 Flagsol Photovoltaic cladding suppliers and installers Flachglas Solartechnik GMBH Muhlengasse 7 D-50667 Cologne , Germany Contact: Mr Hess Tel: +49 221 257 3811 Fax: +49 221 258 1117 Halcrow Gilbert Associates Ltd Consulting engineers Burderop Park, Swindon Wiltshire SN4 0QD Contact: Donna Munroe Tel: 01793 814756 Fax: 01793 815020 Intersolar Manufacturers of amphorous photovoltaic panels Unit Two, Cock Lane High Wycombe Buckinghamshire HP13 7DE Contact: Philip Bouverat Tel: 01494 452 945 Fax: 01494 437 045 IT Power Ltd Consultants The Warren Bramshill Road , Eversley Hampshire RG27 OPR Contact: Bernard McNelis Tel: 01734 730073 Fax: 01734 730820 Newcastle Photovoltaics Applications Centre Consultants University of Northumbria Ellison Building Newcastle-Upon-Tyne NE1 8ST Contact: Professor Bob Hill Tel: 0191 227 4594 Fax: 0191 227 4561 Ove Arup and Partners Consulting engineers and architects Bede House All Saints Business Centre Newcastle Upon Tyne Contact: Ray Noble Tel: 0191 261 6080 Fax: 0191 261 7879 Schüco International Photovoltaic cladding suppliers Whitehall Avenue , Kingston Milton Keynes MK10 OAL Contact: John Stamp Tel: 01908 282111 Fax: 01908 282124 REFERENCES 1 Dr David Carson (1994). Letter to the editor, Sunday Times, 18 September 1994 2 Business Insurance, 28 October 1991 3 Department of Trade and Industry (1995). Digest of United Kingdom Energy Statistics. London. HMSO. 4 National Audit Office (1994). Buildings and the environment. London. HMSO. 5 Department of Trade and Industry (1995). Energy paper 65: Energy projections for the UK. Energy use and energy-related emissions of carbon dioxide in the UK, 1995-2020. London. HMSO. 6 London Research Centre (1993). London Energy Study. Energy use and the environment. London. 7 Building Research Establishment (1995). Personal communication. 8 Department of Trade and Industry (1992). The Potential Generating Capacity of PV-Clad Buildings in the UK, ETSU S 1365-P1 9 Department of Trade and Industry (1993). A Study of the Feasibility of Photovoltaic Modules as a Commercial Building Cladding Component, ETSU S/P2/00131/REP 10 Department of Trade and Industry (1993). A Study of the Feasibility of Photovoltaic Modules as a Commercial Building Cladding Component, ETSU S/P2/00131/REP 11 Energy Technology Support Unit (1994). An Assessment of Renewable Energy for the UK HMSO, London. 12 Schüco (1995). Personal Communication 13 Architecture Today (1994). Survey Volume 51, pp7-8, ABC Business Press. 14 Ove Arup (1995). Personal communication – Costs of PV-Integrated Rainscreen Cladding. 15 Ove Arup. (1995). Personal communication. Costs of PV- Integrated Rainscreen Cladding. 16 Architecture Today (1995). Energy – Light touch: designing with photovoltaics Volume 60 pp 23-29, ABC Business Press. 17 Northumbria University (1995). Northumbria Solar Project – Information pack January 1995. Northumbria University. Newcastle. 18 Department of Trade and Industry (1995). The Potential for Building Integrated PV Systems, DTI, March 1995