To assess suitability ofsolar collector systems with polymeric materials versus those with moretraditional materials such as metals a case study was undertaken within theframework of Task 39 of the IEA Solar Heating and Cooling Programme. In thisstudy one solar heating system with polymeric solar collectors were comparedwith two equivalent but more traditional solar heating systems, one with flatplate collectors and one with evacuated tube solar collectors. Life Cycle Assessment(LCA) results obtained clearly indicated that the polymeric solar collectorsystem is the most favourable as regards climatic and environmentalperformance. In terms of climatic and environmental costs per solar heat collected,the differences between the three kinds of collector systems, however, aresmall when compared with existing energy prices. In the choice between arenewable heat source and a heat source based on the use of a fossil fuel,which was also analysed in the present study, the conclusion was that forclimatic performance to be an important economic factor, the rate of carbondioxide emission must be considerably increased above the level given by thepresent EU carbon dioxide emission trade rate. The rate would be at least ofthe same order of magnitude as the general carbon dioxide emission tax rateemployed in

Sweden.An alternative to an increase in the EU carbon dioxide emission trade ratewould be to introduce a tax system based on environmental cost, making use ofe.g. Ecoindicator99, to include also other impacts on the environment not justthe greenhouse effect.