Technical and commercial readiness for alternate photovoltaic energy systems, and waste streams from three different photovoltaic systems are examined. This analysis suggests that some uncontrolled waste streams could be declared toxic or hazardous under various provisions of the Clean Air, Clean Water, and Resource and Conservation Recovery Acts. Although some processes could emit large quantities of pollutants, these can be controlled using available technology. Other processes may emit small quantities of more toxic pollutants which will probably not be directly controlled unless significant health hazards are identified. Environmental problems in installation and operation are probably associated with large central-station applications; no significant effects are expected from small decentralized applications. Decommissioning of broken or degraded photovoltaic systems will generate large quantities of solid waste which can be simply disposed of in a landfill or perhaps recycled.