Evaluation of Risks in the Life Cycle of Photovoltaics in a Comparative Context

The greatest potential risks in the photovoltaic (PV) fuel cycle probably are associated with using some hazardous substances during cell material production and module manufacturing. To investigate the characteristics of these risks, we first identified the types and amounts of hazardous substances used during the life cycle of PV systems. Then, we estimated the normalized risks, i.e., accidents, fatalities, and injuries per gigawatt-year of electricity produced, along with the maximum consequences during the PV fuel cycle, based on the U.S. EPA Risk Management Program database of chemical accidents involving listed hazardous substances that are also used in solar cell or PV module manufacturing (e.g., AsH3, PH3, SiHCl3, H2Se, HF, HCl, SiH4). Since incident data for the PV industry were not available, the evaluation of PV risks had to rely on the information from the chemical industry. Our analysis shows that, in terms of statistically expected incidents in the U.S., the PV fuel cycle is much safer than conventional sources of energy (e.g., coal, oil, gas, nuclear, hydro), and by far the safest in terms of potential maximum consequences. A framework is proposed by Brookhaven National Laboratory that encompasses a holistic view of risks and benefits and could allow more comprehensive comparisons; work is in progress to integrate this framework with the ERMON information system being developed by the Institute for Energy of the European Commission’s Joint Research Center.