MODULE II Solar energy technology Page 2

1. General developments in the solar energy technology

The first solar energy systems and devices came on the market in the middle of the seventies favoured by the ongoing oil crises. Many of these first systems still had some small technical problems. Also, the craftsmen who installed the devices had very little experience in dealing with the new technology. So, in many cases the systems and devices did not work as long as the manufacturers had promised. In addition, they very often did not produce the energy yields the buyers had expected. Quite frequently, the handicraft companies also had convinced their customers to buy the new technologies by giving them cost-benefit information which later on turned out to be wrong because the companies themselves were too inexperienced to advice their customers correctly. All these factors contributed to the fact that the solar energy technology never really managed to achieve a broad breakthrough in the customer acceptance and so it only existed in a small market niche for many years.

In the meantime over the last few years however, the environmental awareness in the society has increased considerably. In the first place this was caused by the quickly progressing degradation of our natural living conditions, e.g. by the ozone hole, CO2 emissions, the greenhouse effect, nuclear energy accidents, etc.. With these growing global environmental problems the readiness in the society had increased to change the own consumption behaviour. These developments have contributed to the fact that the customers do not make their purchase decisions in regard to the purchase of new energy technologies any longer exclusively based on economic reasons, i.e. a new energy technology can indeed be a little bit more expensive than a conventional one if it helps to protect the environment.

Another development which is also helping to accelerate the customers acceptance of new energy technologies is the technical progress occurring in this field. So e.g., the independent German "Testing Foundation" ("Stiftung Warentest") today certifies the reliability and quality of the solar technology components available on the market.

In this way, increased environmental awareness and technical progress have considerably contributed that since 1989 the installed solar collector area in Germany has grown from around 325000 m2 to 1,3 million m2 in the year 1995. Experts are expecting further growth with annual growth rates of 20% and more until the year 2000 and beyond.

In contrast to common opinion, the use of solar energy is possible in all of Europe independent from the geographical location. The annual sunshine duration in Europe is between 1500 and 2000 hours and the average global radiation is between 900 kWh/m2/year and 1200 kWh/m2/year - see also diagram 1 and diagram 2. Only some valley and foggy locations have unfavourable conditions for the use of solar energy installations. A correct planning of systems that are especially adapted to those conditions (e.g. by using bigger collectors) can make the use of solar energy possible even in these areas.