Performance assessment of a hybrid photovoltaic-thermal and heat pump system for solar heating and electricity

Abstract

This work investigates a solar combined heat and power systems based on hybrid photovoltaic-thermal heat pump systems for the simultaneous provision of space heating and electricity to residential homes. The analysed system connects a photovoltaic-thermal (PVT) panel, through a PVT water tank, to a heat pump. The study is based on quasi-steady state heat transfer and thermodynamic analysis that takes incremental time steps to solve for the fluids temperature changes from the heat pump and the solar PVT panels. The effects of solar irradiance, size of the water tank and the water flow rate in the PVT pipes (laminar and turbulent) on the performance of the system are analysed. Particular focus is made towards the efficiency (electrical and thermal) of the PVT and the COP of the heat pump. Results show that the minimum COP of the heat pump is 4.2, showing the high performance of the proposed hybrid system. Increasing the water flowrate through the PVT panel from 3 L/min (laminar) to 17 L/min (turbulent) increases the PVT’s total efficiency (electrical + thermal) from 61% to 64.5%. Increasing the size of the PVT water tank from 1 L to 100 L, increases the total efficiency of the PVT panel by 6.5%.