Photovoltaic Roofing in Mediterranean Climate Countries

Transcription

1 1 Photovoltaic Roofing in Mediterranean Climate Countries Pere Alavedra¹, Amado Guzmán ², Mauricio Torres ³, Samantha Gallowayº, Daniel Alavedra" Department of Construction Engineering, Catalonia Polytechnic University, Barcelona, Spain. Abstract: This paper compares the photovoltaic roofing system in the Mediterranean climate countries taking into account economic issues as the investment redemption, the existence of subsidy policies, and also the cost benefit relation and the implicated institutional social factors, the real performance and potential of the building due to its design and location. All of that will have a great importance to decide the implementation of these systems in a warm climate. The new demands brought out by the sustainable issue created the need of studying the building on its phase of utilization, taking into account the energetic saving, the comfort and the use of recyclable materials which guided us to different solutions for this system. The use of photovoltaic roofing composed by photovoltaic cells offers the opportunity to produce electricity in the urban zone taking advantage of an inexhaustible natural free source. Key words: sustainability; photovoltaic, subvention program. Introduction The recent concern about world climate changes mostly produced by the fossil fuel consumption, has developed new technologies and laws to prevent this impact. The construction generates almost a third of the global pollution, attending to that, the constructors must generate buildings with sustainable resources such as materials with low ecological impact, materials with thermal isolation to maximize energy utilization as well as using systems that contribute to energy production. The human being spends most of its time between walls; this requires a good environment to develop its functions. Usually for the development of these functions, the use of energy is required, mainly used for air conditioning, heating & lighting, which is reflected in terms of energetic consumption. The actual building has to fulfill the new sustainable demands during its different life cycles: design, construction, use and demolition. During the design period, it s important to have in mind the implementation of materials with low ecologic impact, foreseeing users comfort and energy consumption as well as the use of recyclable materials. Authors Note: Pere Alavedra¹,Ph.D. Industrial Engineer, associate professor, (pere.alavedra@upc.es); Amado Guzmán²,architect, (amado.guzman@upc.es); Mauricio Torres³,architect, (mauricio.torres@upc.es); Samantha Gallowayº,architect (samantha.galloway@upc.es); Daniel Alavedra",lawyer, (dani.alavedra@upc.es).

2 2 During the buildings construction and use phase, it no longer only requires the principal functions, but also new requirements such as comfort for the inhabitants, image and low energy consumption are very important too. Finally, we find ourselves in the demolition phase, where the materials must be easy to recycle showing the importance of their selection during the design phase. In Mediterranean countries the thermal gains produced during the summer are very high, that is why the implementation of photovoltaic roofing with new proposals of isolation is necessary. The photovoltaic roofing not only produces energy, it also contributes to reduced thermal gains, and shows a considerable reduction of costs generated by the use of consumption systems, such as air conditioning or heating. In the case of this article one is going to analyse the main PV producers in Mediterranean countries as Spain, France and Italy, their main principles in photovoltaic, their subsidies and their future perspectives, with the objective of establishing a comparison between these countries. The cost analysis in this article is focused on the four fields of sustainability. Analysing it from an economic perspective, the cost of investment and maintenance, from an institutional perspective, the subventions; from a social perspective, the comfort, image of the building and finally from an environmental perspective, the ecologic costs generated by the use of exhaustible energies. 1. Photovoltaic energy The solar energy is practically inexhaustible; the sun is a clean and renewable energy, this is the - reason why there are so many investigations about it nowadays. It s so abundant, that the energy that the earth receives in 30 minutes is equivalent to the energy consumed by humans during one year. (Greenpeace). The advantages that we find with PV are: We can place it almost anywhere obtaining good results in the main cases, they are easy to transport, their installment is simple and it doesn t produce noise during the process. Besides it has an excellent durability and needs little maintenance. Generally the period of life of these systems is above 30 years but we can find systems from the 1960 s still operative. The PV generates electricity during the whole year. Normally in the summer it increases the electricity generation because the days are longer. During cloudy days it still operative but decreases its functions. Its is recommended to do the maintenance during the night to avoid electric shocks (ASIF) The surface needed to produce 1kWp depends mainly on the type of panel that you want to use, but for practical reasons one can consider it a surface of 10 m2 as it is easier to adapt to roofs to generate electricity. The photovoltaic industry is growing annually at 30% rate, reducing their costs in a 5% on the production of PV module and it intends to continue like that. Today it could produce a quarter of the global energy consumption through the implementation of PV in buildings. 2. Perspective for the next years In the year 2010 it is hoped that the systems in buildings will cover 50 % of the global demand producing 3000 MW of energy following the Commission s White Paper on Renewable Energy. For the year 2020 an output of 276 terawatt hours of energy is expected and finally for 2040 that the production will be more that 9000 terawatt hours which would be 26% of the projected global demand. (EPIA and Greenpeace)

3 3 3. PV In Europe Many programs have been developed in Europe regarding of the implementation of PV energy. We can find a good example in Germany. This country implemented its 1,000 roofs program that was carried out in the early 1990s, although the must remarkable one is the German project "100,000 roofs". This program has shown excellent results. It started in 1999 installing 300 Mw of solar electricity and accomplished its goals before its predetermined deadline. During the two year period Western Europe governments have invested about 400M. and Germany was the largest single investor with more than 114M. (IEA) Italy France Spain Germany Switzerland Austia Instaled PV capacity M w (2002) Production of PV Electricity in some countries of the UE, Source (IEA) Price Evolution in the price of PV, Source: ASIF

4 4 4. Electricity price in Europe It is important to analyze the cost of electricity in the EU to be able to evaluate the later recovery of the total equipment cost. In almost all EU countries the price of electricity has decreased during the period of 1996 to 2002, in some countries more than 12%. Price of electricity for a domestic user Dc (Euros/100Wh) Belgium 14,94 13,76 France 13,66 11,49 Germany 16,43 16,99 Italy 21,48 19,84 Netherlands 12,12 17,58 Portugal 13,17 13,22 Spain 12,48 10,63 United Kingdom 10,02 10,61 Price for electricity in some of the EU countries, Source Eurostat. 5. Financing mechanisms Governments have a central role in the exploitation of solar energy, effecting the legal regulations of new buildings, construction and safety standards as well as urban planning. The Principal financing mechanisms in these countries are: PV Grants The actual cost for photovoltaic production is still very high so some of the countries concede subsidies in addition to compensate the owner for the high costs of the PV system. The average nowadays in the EU is between 30-50%, but in some cases it reaches 75% of the cost (see the case of Italy). Feed In This is the model successfully used in Germany, which consists in regulating the electricity law which forces the electric companies to buy electricity induced to the net at largest costs. In the case of Germany s program 100,000 roofs program the actual cost was 0.49 per W induced to the net. In this example the cost will be amortized with the energy production but the application of other financial costs is necessary to reduce the initial expenditure. Fiscal Incentives In some countries like Italy the government implemented tax regulation, so the consumer of the Photovoltaic system could amortize the cost with fiscal requirements. Loans at low interest Loans are given by enterprises or associations to support the largest initial cost of the PV system.

5 5 Overview of the principal financing mechanisms used in Mediterranean countries. Financing mechanism Incentives Grants/ Subsidies Feed In Fiscal Incentives Loans at low interests There are other financial mechanisms as Greenprice, certification, to mention some, but in the case of Mediterranean countries the use of these programs are hardly used. So we are not going to considerate those in this article. 6. PV in Spain Spain is situated between 36º and 43º coordinates and it has an media annual radiation of kwh/m2 together with Portugal they are considered two of the countries in the EU with the best characteristics of the production of solar energy. Besides the fact that the Spanish territory produces 8% of the worlds solar cells. Nowadays the cost of the production of 1 Wp, could be between 6,50 and 7,5 euros. (ASIF) Spain has progressed during the last ten years implementing different programs to sustain the installation of photovoltaic systems. Today the energy produced has exceeded the 19,2 MWp. positioning it in one of the most important producer countries with this kind of energy. Installed Year potential (kw) Mwp Table: Evolution of the installation of PV in Spain, Source: IDEA Graph: Evolution of the PV in Spain. Sources: IDAE+ASIF In the year 2002 the actual production of energy in Spain was 5 MWp situating it on one of the largest consumers of PV electricity in the EU. 2 Data not provided. Aproximated.

6 Programmes Different inquiries developed by different groups such as Greenpeace proves that almost 100% of the questioned people would implement PV systems in their homes if they would get the economic support. In Spain the main subsidy is the ordinance of 1998, which obligates the electrical companies to buy the energy produced by these systems at a price of 0,39 (RD 2818/1998) The IDAE also gives support such as credits for the implementation of the PV systems. IDAE in collaboration with the ICO finances the installations, with a credit of 70% of the cost and extra support for those of less than 100 Kw. There are also fiscal Incentives. The European commission also support the use of PV with 35% according to the Hip-Hip program. With the actual Financing mechanism of feed in with out the grants given by IDAE and ICO, the return period would be from 19 to 25 years (Greenpeace) In Spain there are some programs of solar energy production which intend to have by the end of 2010 an installed solar power of 143,7 MWp. This is equivalent to a total of 4.5 Million m2 although studies have been made by the EurObserv'ER which reflects that at today s growth rhythm another 40 years would be necessary to reach the goal. 7. PV in France In the south of France, which is the area that has almost the same characteristic of the countries previously mentioned, the solar radiation is the same that Spain, kwh/m2. France has increased considerably its photovoltaic installations since 1996, and during the last year (2002) more than 3 MW were installed in French territory. Installed Year potential (kw) Mw Evolution of the installation of PV in France, Source: ADEME Today the energy produced in France has exceeded the 17,2 MWp

7 Programmes The interest of PV systems in France is still growing. It is important that research institutes such as CSTB in partnership with ADEME have organized different campaigns for the assessment of the PV modules in buildings and congresses with the main objective of promoting the use renewable energy. (Chevalier) France is one of the countries with less subventions compared to the rest of Mediterranean countries. Some of these incentives are the feed in, which started in March of 2002 through buying consumed energy at 0.15 Kw in continental France and 0,30 in Corsica and overseas departments. These cost have decreased 5% per year since The main national grant program France comes from ADEME, which supports 15% of the initial cost of the PV system. In some cases local activities support up to 30% of the system but the major initiative comes from the European commission with the Hip-Hip program that supports with 35%. Another support system is that the cost of PV systems is subventioned to reduce their initial cost per Watt connected to the grid, the actual cost varies between 4,6 minimum and 6,1 attempting to reduce the cost in January 2005 to 3,8 and 4,9 per watt, (ADEME) Today the cost production for a 10kWc Nowadays could be around 60,000, but if we implement the subventions from the European Commission, ADEME and the regional ones, this would diminish to a 30,000 to 48,000 which is still being a big initial cost. So the implementation of loan or grant programs are necessary. (Hip-Hip program) 8. PV in Italy Since the beginning of the 1980 s, Italy has invested in research and photovoltaic programs. It has become one of the most important producers of PV energy since then. Nowadays the price of photovoltaic energy in Italy is about 3,5 adn 4,3 per watt, making these prices one of the lowest registered in the European community. Cumulative Year Installed potential (MW) , , , , , , , Mw Evolution of the installation of PV in France, Source: IEA Today the energy produced in Italy has exceeded the 22 MWp

8 Programmes The main public financial support comes from the Italian roof-top programme, founded at the beginning of It is mainly focused on small PV plants (1-20 kw) supporting the 50% of the cost, with this program and other regional programs the contribution to the PV system could be up to 75% maximum. Also Italy has been invited to participate in the Hip-Hip program which supports 35% of the cost coming from the European Commission. 9. Overview of PV in Mediterranean countries Year Financing Mechanism Grant Feed-In Fiscal I. Loan Spain 19,2 MWp 135 MW 30% - 35% France 17,2 MWp % Italy 22 MWp 300 MW 75% Maximum % / 5 Years Conclusion The generation of clean energies are necessary to decrease the CO 2 emissions into the atmosphere according to the Kyoto protocol and the White paper issued by the European Commission. Considering that Mediterranean countries have the best characteristics in the EU, they should mainly focus on programs to give major impulse to the PV systems. The energy generated from PV has grown considerably in Europe and through the generation of programs we will manage to get a more sustainable world. As we can see in this article the use of only one financial mechanism is not sufficient, so the need to implement integrated programs could give better results. Studies indicate that it would be possible to reach these goals by the year 2010, but development and diffusion of existent and new programs is necessary. 1) Feed-In Tariff still under consideration.

9 9 References: ADEME, 2002, Photovoltaic electricity industry in france ASIF, 2003, Situación actual de la energía fotovoltaica en España. CHEVALIER J. 2002, Introducing practically the environmental concern when prescribing construction products, International conference Sustainable Building 2002, Oslo, Norway. BIKAS, D. and Kantoleon, K Environmental evaluation of thermal inertia factors of buildings envelopes as a function of Solar Absorbity. Sustainable Building Conference Oslo DAVILA, L Et. Al, 2001 Las energias renovables en españa, Era solar 108.EC, European Comision, Solar ElectriCity Guide, Energy publication. EPIA (Eurpean Photovoltaic Industry Asosiation), 2002, Executiv Sumary, Solar Electricity in 2010 EPIA and Greenpeace, Solar Generation: electricity for over 1 billion people and 2 million jobs by 2020 GREENPEACE, 1997, Report Building homes with solar power. IEA, 2002 Market deployment strategies for PV systems in the built environment: An evaluation of Incentives,Support Programmes and Marketing Activities. IEA- PVPS 7-06:2002 IEA, Trends in photovoltaic applications, IEA-PVPS T1-12:2003 LORENZO E., 2001La energía que producen los sistemas fotovoltáicos conectados a la red. Era solar 107. NORDMANN T., 2001, Subsides versus rated based incentives; fer technologyeconomica- and market development of the PV. The European experience. TNC Consulting AG, Seestrasse 141, CH-8703 Erlenbach, Switzerland SEBA, 1998 Manual del Usuario de Instalaciones Fotovoltaicas (para instalaciones autónomas). Ed. Progensa. Web Links: