The performance of photovoltaic (PV) module outdoors suffers from attained high module temperatures due to irradiation as a result of the negative temperature coefficient of their efficiency. Phase change materials (PCMs) are investigated as an option to regulate photovoltaic module temperature and thereby reduce its electrical efficiency decrease. In this study, a simplified heat balance model is used to calculate the extra energy gain; such a PV/PCM system can bring on an annual basis. With present day commercially available PCM materials, a moderate increase of up to 3% of the total energy output can be expected. When taking into account the additional PCM material cost, a PV/PCM module presently is not economically viable. For an acceptable payback period of 10–20 years to be reached, the heat storage capacity of a PCM would require an increase of about one order of magnitude, which is presently not realistic. Nevertheless, a combination with building climate control in which the PCM plays a double role controlling both the PV temperature as well as the inside climate temperature may be feasible. Copyright © 2011 John Wiley & Sons, Ltd.