Computational fluid dynamics (CFD) is used to model experimental data corresponding to convection occurring under a photovoltaic (PV) panel. Further experimental data is used to validate the model where the satisfactory agreement is received. A standardised condition is set up to allow the effect of varying three geometric parameters to be examined. These are the air gap height (10-500 mm), air gap orientation angle (0-90 degrees from the horizontal) and fluid velocity magnitude (0-3 m/s). The optimum mounting conditions for the PV panel is obtained and maximised electrical efficiency found to favour angles greater than 50 degrees and air gap heights that give an aspect ratio of 60. Mixed convection opposed to natural convection is found to be more effective, with greater efficiencies obtained for larger fluid velocities. (C) 2011 Elsevier Ltd. All rights reserved.