Use of plastics in solar energy applications

discussion of the state-of-the-art on the use of plastic materials in solar energy applications is presented. with particular emphasis on their suitabity and durability. The availnbility of plastics in many typts and shapes (including sheeting material, films and foams)accounts for the wide range of current and potential applications in solar energy installations. Consequently, actual and potential uses of plastics include: covers (zings), honeycomb structures and housings for llat-plate collectors; relkcting surfaces. optical lenses, shells. structural and support members for solar concentrating collectors; and insulation and piping. The plastics that have been discussed in this attick in relation to their use as components in solar installations include poly(mctbyl methacrylate)(PMMA), polyuubonate (PC), glass fiber-reinforeed polyester (GRP), poly(viny1 fluoride)(PVF), fluorinated ethylenc-propykne (FEP)copolymer. poly(ethykne terephthalate)(PET)and various foamed plastics. The aging behaviour of most of these plastics has been widely studied for normal outdoor exposure and in artificial weathering devices, and are thus briefly described here. Very Little information is available, however, regarding their short-term performance under actual service conditions in solar energy installations; none has been reported on their long-term durability. Plastics have various degrees of flammability and therefore special care should be taken by using materials with adequate tire resistance andlor appropriate design in applications where a fire hazard may exist.