Building-integrated photovoltaic (PV) systems are increasingly common in developed countries and have the potential to contribute significantly to electricity generation as a benign alternative to fossil fuel generation. The University of Nottingham has recently completed a new campus, The Jubilee Campus. PVs are integrated into the roofs of four atria for the teaching buildings in the new campus. This paper presents the performance of roof-integrated PVs using CFD (computational fluid dynamics). A commercial CFD package was used to predict the air flow and thermal environment in the atria with radiative and convective heat transfer. The effect of ventilation strategies on the performance of PV arrays and the indoor climate was investigated. Key parameters investigated include the size and location of air inlet, ventilation rate, roof heat flux and air flow rate through a channel under the roof. For effective cooling of roof PV arrays, cool outdoor air should be introduced through an opening positioned close to the roof or an air channel underneath the roof.