LIFE-CYCLE ANALYSIS OF SILICON-BASED PHOTOVOLTAIC SYSTEMS

The analysis focuses on a comparative evaluation of emissions from conventional private passenger vehicles versus the environmental burdens of electric passenger vehicles. The batteries of electric passenger vehicles 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 Western Germany, and the tentative time period is around 2005. The analysis is based on detailed data collections for the fabrication of technical silicon, multi- and monocrystalline standard, MIS-I cells, and amorphous cells. The information on substance discharges into the environment permitted an environmental assessment to be made via evaluation criteria, 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 environmentally beneficial, but due to its manufacturing processes PV is not a zero emitter; supporting structures should be as low-weight as possible with minimized material requirements for low emissions from PV-system fabrication; 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 development priority should be given to the industrial fabrication maturity of high-efficiency modules.