Photovoltaic manufacturers rate their modules based on their maximum power output. This nominal power corresponds to the commonly accepted standard test conditions (STC: cell temperature Tcell=25 oC, insolation G=1kW/m2, air mass ΑΜ=1.5). In reality, insolation is lower and cell temperature higher, both being factors that affect power generation in a negative fashion. In the present paper, the possibility of cell temperature reduction will be investigated using one of the proposed methods of thermal control, phase change materials. The photovoltaic module, both as a unit and as a system in direct contact with a phase change material, will be simulated using a finite difference method.