EuroSun2008-5

Increase of the loss potential caused by severe hailstorms

The challenge of the estimation of the real existing loss potential at solar energy systems caused by severe hailstorms is given in the combination of high accounts on, at present, relative small areas, aggravated also by the high spatial concentration of such thunderstorms. This is also the reason why insurance and re-insurance companies accept such losses tacitly up to now and don’t itemize damages at solar energy systems in their loss statistics separately. Nevertheless, it is quite clear that the risk of damages on solar energy systems will enormously increase if we consider the rapid development of the solar thermal as soon as the PV-market in Europe in the last decades and if we also consider the aspiration of the EU to enhance the percentage of sustainable energy up to 20 % until 2020 and up to 50% until 2050 related to the overall energy demand, Fig. 4 and Fig. 5 show the annual rates of growth of solar thermal collectors and PV-modules which are registered up to now as well as predicted until 2020.

Also the establishment of solar thermal as well as photovoltaic power stations for the industrial electricity generation and the increasing installation of large solar thermal systems to supply local heat grids or solar driven cooling systems as well as the furnishing of process heat for industrial processes results in a higher potential of economical losses. 88.8% of the present installed collector area of solar thermal systems in Germany are small systems up to 20 m2 Systems larger than 20 m2 are only 11.2%. Systems over 50 m2 even only 1.7%. For the compliance of the achieved objectives of the EU, the amount of large solar systems has to be increased appreciably. The 2007 published sustainability study of the Sarasin Bank predicted the annual growth rates in the field of large solar thermal systems as given in Fig. 6.

A further aspect which will influence the increase of the economical loss potential is given by the architectural integration of solar thermal collectors and PV-modules into the building shell. Solar energy systems will no longer be installed as several patchworks at the existing building shell but more and more as an integrated component of the building shell. Apart from the function just as an energy collecting device such integrated components have to fulfil other additional functions. Moreover, the efforts to exchange such integrated components in the case of some damages will be more expensive.