An experimental study on simultaneous electricity and heat production from solar PV with thermal energy storage

Abstract

Electrical energy conversion of solar photovoltaic (PV) systems is significantly influenced by the PV module temperature, where the overheating of the module leads to a drop in power generation. A photovoltaic/thermal (PVT) solar hybrid system produces more electrical power by simultaneously cooling the PV with thermal energy output using heat transfer fluids (HTF). The performance of a PVT hybrid solar collector using thermal energy storage (TES) and two HTFs is experimentally investigated to improve the PV system's electrical energy output and the semi-conductor's temperature distribution. The outdoor readings are measured in February and July to determine the variations in the electrical and thermal responses of the PVT. Water at a flow rate of 0.00833 kg/s is in natural circulation mode, and the air is circulated through the channel at 0.0069 kg/s using a blower. Two water inlets and outlets are provided to improve the panel temperature distribution. The airflow path is enhanced by arranging containers that split and distribute the airflow towards the two sides of the containers. OM42 is selected as a phase change material (PCM), and thirteen containers are attached with a copper absorber sheet. The study shows that the hybrid cooling PVT collector enhances electrical power conversion by reducing panel temperature significantly—a maximum temperature drop of 7.5 °C. The maximum electrical efficiency of the hybrid panel in February is 15.71% which is about 22% higher than the conventional panel. The maximum thermal and overall recovery efficiencies are maximum of 69.25% and 84.40%, respectively, at constant water and airflow rates. In July, the maximum electrical efficiency of 15.2% is observed, which is about 22% higher than that of conventional PV system. The maximum thermal and overall efficiencies are observed to be 70.8% and 85.7%, respectively. The economic and environmental analysis of the proposed hybrid PVT system shows comparatively lesser carbon emissions and quicker payback periods than that of the conventional PV system. The present hybrid PVT design effectively produces electricity, hot air, and hot water simultaneously and effectively.