Environmental costs of photovoltaics

Photovoltaic (PV) systems are almost entirely benign in operation, and potential environmental hazards occur at the production and disposal stages. There are well established methods of monitoring and controlling potential hazards caused by the semiconductor materials used in PV modules such as silicon, copper indium diselenide and cadmium telluride. The main environmental hazards of photovoltaics are connected to the production processes. These processes require an input of energy, and this energy is derived from the standard fuel mix of the nation in which production takes place. The production of PV systems therefore has associated with it, emissions of greenhouse and acidic gases. However, as the new thin film PV technologies come into production, and the scale of production increases, the energy input to PV systems will decrease considerably, with consequent reduction in carbon dioxide emissions, to levels below that of other electricity generating technologies.