Technical feasibility study of passive and active cooling for concentrator PV in harsh environment

Abstract Concentrator PV (CPV) has the potential to replace the expensive PV material with cheaper optical elements which also enhance the overall electrical output. The triple junction III-V solar cells are integrated with CPV systems as they are more efficient, have a better response to high concentration, and lower temperature coefficient. However, using high solar concentration ratios will increase the solar cell surface temperature which is inversely proportional to the PV electrical efficiency. This work investigates the feasibility of passive and active cooling to maintain a single triple junction PV cell surface temperature and electrical performance under high solar concentration in the harsh environment like Saudi Arabia where ambient temperature can reach up to 50 °C in summertime. To study the feasibility of passive cooling in such an environment, CPV thermal simulation is undertaken to examine the performance of two heat sink designs, namely, Round Pin Heat Sink (RPHS) and Straight Fins Heat Sink (SFHS) under different ambient temperatures. The simulation reveals that passive cooling using those two heat sinks with concentration ratio of 500x is insufficient to maintain a single PV surface temperature below the operational limit set by the manufacturer, i.e. 80 °C, especially at high ambient temperatures which may degrade the life of the solar cell. On the other hand, 0.01 m/s water active cooling simulation results prove its ability to maintain the solar cell surface temperature around 60 °C and electrical efficiency at 39.5% regardless of the ambient temperature. Also, the outlet water average temperature for a single and multiple CPVs were examined and results show that placing 14 single CPVs above the cooling channel will raise the temperature to 90 °C which makes the coupling to a single stage absorption heat pump for cooling demand applicable.