An experimentally validated computational fluid dynamics (CFD) model of a novel building integrated photovoltaic-thermal (BIPV/T) collector is studied to determine the effect of active heat recovery on cell efficiency and to determine the effectiveness of the device as a solar hot water heater. Parametric analysis indicates that cell efficiency can be raised by 5.3% and that water temperatures suitable for domestic hot water use are possible. Thermal and combined (thermal plus electrical) efficiencies reach 19% and 34.9%, respectively. A new correlation is developed relating electrical efficiency to collector inlet water temperature, ambient air temperature and insolation that allows cell efficiency to be calculated directly. (C) 2009 Elsevier B.V. All rights reserved.