A novel heat pump system is proposed in that the PV/T collector is coupled with a solar assisted heat pump and works as an evaporator. The cooling effect of the refrigerant allows the PV modules to work at lower temperature and so its photovoltaic efficiency is improved. Mathematical model has been developed to analyze the complex energy conversion processes. Numerical simulation was then performed based on the distributed parameters approach. An experimental rig was also built to verify the real performance of the system as compared to the simulation model prediction. The results indicated that this photovoltaic solar assisted heat pump (PV-SAHP) has better coefficient of performance (COP) and photovoltaic efficiency than the separate units. Under the experimental conditions, the COP of the PV-SAHP reached 8.4 and the average value was around 6.5, whereas the average photovoltaic efficiency was around 13.4%. The experimental results were found in good agreement with the theoretical predictions on the system responses to changing environmental conditions. (c) 2008 Elsevier Ltd. All rights reserved.