LIFE-CYCLE ANALYSIS OF SILICON-BASED PHOTOVOLTAIC SYSTEMS

The analysis focuses on a comparative evaluation of emissions from con ventional private passenger vehicles versus the environmental burdens of electric passenger vehicles. The batteries of electric passenger ve hicles are loaded during daily working hours partly via silicon-based PV panels covering the vehicle parking areas (solar service stations), and partly via the public electric grid. The data base refers to West ern Germany, and the tentative time period is around 2005. The analysi s is based on detailed data collections for the fabrication of technic al silicon, multi- and monocrystalline standard, MIS-I cells, and amor phous cells. The information on substance discharges into the environm ent permitted an environmental assessment to be made via evaluation cr iteria, quantitatively expressed as burden values. The results lead to the following main conclusions on the environmental impacts of Si-PV cells and to the major recommendations for PV development focuses: To substitute SI-PV for substance-emitting technologies is environmentall y beneficial, but due to its manufacturing processes PV is not a zero emitter; supporting structures should be as low-weight as possible wit h minimized material requirements for low emissions from PV-system fab rication; PV only makes sense for applications relevant to the energy economy with high-efficiency modules and minimized electricity demand to enable solar supply shares to be as high as possible; and highest d evelopment priority should be given to the industrial fabrication matu rity of high-efficiency modules.