Effect of Phase Changing Material use on The Efficiency of Photovoltaic Modules

An experimental study has been conducted to reduce the loss of efficiency caused by the increase in temperature in photovoltaic (PV) modules. The aim of this study is to decrease the instantaneous temperature changes and overall mean temperature in the system to prevent the uncontrolled increase of the module temperature, while reducing the loss of performance caused by the increase in temperature. The experiment was carried out by using a pair of polycrystalline and a pair of monocrystalline PV modules. Both types of the PV modules had 10W power and exact same features. A reference/control module has been selected from each type of PV modules and these control modules has been added to the system as traditional PV modules. Heat pipe and phase changing material were applied to the back surface of other PV modules. The phase changing material was used to store heat on the PV module surface and to transfer the stored heat to the heat pipe. Calcium Chloride Hexahydrate was the preferred material to use as the phase change materials in the system. The system temperature was then brought under control by passing water through the heat pipe in the system. The temperature measured on the surface of the reference/control module was 30-80ᵒC during the day, while the temperature ranged between 30-40ᵒC in the experimental modules with phase changing substance. We found that performance loss caused by increase in surface temperature in reference/control modules reaches up to 20%. Whereas, the performance loss in the experimental modules is only as high as 1% under the same conditions. The mean temperature of the active PV modules has been reduced by using heat pipes and phase changing material. Lowering the mean temperature subsequently reduced the loss of performance caused by the increased temperature