Elevated operating temperatures reduce the solar to electrical conversion efficiency of photovoltaic devices. This paper presents an experimental evaluation of phase change materials for thermal management of photovoltaic devices. Two particular phase change materials were used to moderate the temperature rise of photovoltaics. The thermal performance of different internal fin arrangements for improving bulk PCM thermal conductivity are presented. Using RT25 with internal fins, the temperature rise of the PV/PCM system can be reduced by more than 30 degrees C when compared with the datum of a single flat aluminium plate during phase change. Phase change materials are shown to be an effective means of limiting temperature rise in photovoltaic devices. (c) 2005 Elsevier Ltd. All rights reserved.