Outdoor performance of a low-concentrated photovoltaic–thermal hybrid system with crystalline silicon solar cells

The main problem of the photovoltaic system is the high cost of solar cells. One possible solution is to concentrate the solar radiation to minimize the required cell area for the same output. In this paper a low-concentrating photovoltaic–thermal hybrid (PV/T) system was set up to study the electrical and thermal outputs under different weather conditions. The concentrator in the system was designed using Fresnel lens and flat mirrors to get a uniformly concentrated irradiation on the solar cells. The results show that on a clear day the electrical efficiency is about 10% and the thermal efficiency is about 56% for our system. Irradiance is the most important factor to characterize the weather. When the irradiance is above 350 W/m2 the electrical output will saturate and when it is above 162 W/m2 the thermal energy can be effectively output in our system. The system is also modeled to predict the output and describe the concentrator’s performance. By this model different concentrated PV/T systems can be compared in the electrical and thermal outputs and also the performance of concentrators.

► Four different weather conditions are considered and characterized.
► The concentrator is carefully designed to get a uniformly concentrated irradiation.
► A model is made to evaluate the system with optical efficiency of concentrators considered.
► Direct and diffuse lights are distinguished in the model.