Elevated operating temperatures reduce the efficiency of photovoltaic devices. The use of a phase change material to moderate building integrated photovoltaic temperature rise has been investigated by experiments and numerical simulations. Experimental data are used to validate the previously developed two-dimensional finite volume heat transfer model conjugated hydrodynamically to solve the Navier-Stokes and energy equations. A parametric study of a design application is also reported. Temperatures, velocity fields and vortex formation within the system were predicted for a variety of configurations using the experimentally validated numerical model. Temperature distributions predicted for different insolation and ambient temperatures at the photovoltaic surface show that the moderation of temperature achieved can lead to significant improvements in the operational efficiency of photovoltaic facades. (C) 2004 Elsevier Ltd. All rights reserved.