Experimental Study on a Solar Photovoltaic Thermal Module Integrated with Phase Change Material

Photovoltaic modules are used to directly convert solar radiation into DC current. It is a fast growing renewable energy technology which is seen by many as a potential alternative to conventional sources of power generation. However, low efficiency of photovoltaic modules remains a big barrier in widespread adoption of this technology. A major portion of solar radiation falling on a PV module gets converted into heat which is undesirable as it increases the operating temperature of the module and reduces its conversion efficiency. The application of Photovoltaic thermal (PV/T) system is an effective method of removing heat from PV modules. This work presents a PV/T module which utilizes phase change material (PCM) to simultaneously produce electrical output and warm water for domestic use. A solar photovoltaic module is modified to a photovoltaic thermal (PV/T) module by attaching a serpentine shaped copper cooling coil and a PCM container on its rear side. Paraffin wax is used as PCM as its melting point lies within the operating temperature range of the PV module. PCM is embedded in the metal matrix to improve its thermal characteristics. Experiments are conducted in outdoor conditions for the analysis of electrical efficiency, power output and thermal efficiency of the PV/T module at cooling water circulation rates of 200, 400 and 600 mL/min. Maximum improvement in electrical efficiency of 7.5% was achieved due to 14% reduction in peak temperature at 600 mL/min of flow rate. Maximum thermal efficiency of 42.5% was achieved by the modified PV module.