Performance evaluation of 7.2 kWp standalone building integrated semi-transparent photovoltaic thermal system

Abstract

A building integrated semi-transparent photovoltaic thermal (BiSPVT) system involves an integration of semi-transparent photovoltaic modules with buildings along with the provision to harvest thermal energy and provide daylighting. In this paper, a thermal model has been developed for a 7.2 kWp BiSPVT system to evaluate the yearly energy generation potential of the system. Through the experiments performed on the system with variation in number of air changes per hour (N) in its room, the efficacy of the model has been presented. It has been found that N creates negligible decrease in PV cell temperature whereas with N = 11 (day2) and N = 22 (day3), the maximum room temperature has been found to decrease by 1.3 °C and 1.9 °C respectively. Further, the efficiency of SPV array has been evaluated in real time i.e. with the array connected to balance of system (power conditioning unit (PCU), AC load, battery bank). The average efficiency of SPV array when loaded at maximum power point by the PCU is found to be 6.90%. The total energy generated in a year by the BiSPVT system is found to be 8927.1 kWh. Additionally, the impact of poor health of battery bank on electricity generation for standalone PV systems has been presented.