Comparative investigation of multi-pass flow for air photovoltaic/thermal collectors

Recently, much emphasis has been placed on improving the efficiency of solar systems with co-generation as a particularly promising research area. This work focuses on the integration of photovoltaic (PV) and solar air heater systems with the aim to evaluate electrical and thermo-hydraulic performances. Five air PV/Thermal collector designs are investigated numerically. These designs are classified based on the direction of flow and number of passes. The first design model is a single duct single pass, in which air flows underneath the PV panel and the upper surface of PV subject to ambient conditions. The second is similar to the first one, but with an air gap added between the upper surface of the PV module and glass cover. In the third, air flows under and over the surfaces of the PV module in the same direction. The fourth is similar to the third one, but the flow pathways are in opposite direction. In the fifth, air flows between the glass cover and the PV module and reverses in the second pass between the PV panel and lower absorber plate, making a U-shape flow. The fifth model displays the best thermal performance whilst the third offers the highest electrical efficiency.