The energetic and environmental life cycle assessment of a 4.2 kW(p) stand-alone photovoltaic system (SAPV) at the University of Murcia (south-east of Spain) is presented. PV modules and batteries are the energetically and environmentally most expensive elements. The energy pay-back time was found to be 9.08 years and the specific CO2 emissions was calculated as 131 g/kWh. The SAPV system has been environmentally compared with other supply options (diesel generator and Spanish grid) showing lower impacts in both cases. The results show the CO2-emission reduction potential of SAPV systems in southern European countries and point out the critical environmental issues in these systems. (C) 2009 Elsevier Ltd. All rights reserved.