Comparative Life Cycle Assessments of Photovoltaic Thermal Systems with Earth Water Heat Exchanger Cooling

Abstract

Photovoltaic (PV) technology is a commercially established technology for direct generation of electricity using solar energy. However, one drawback of this technology is that its electrical efficiency decreases with increase in panel temperature beyond standard surface temperature of 25°C. To maintain the panel surface temperature, photovoltaic thermal (PV/T) cooling technology with earth water heat exchanger (EWHE) could be a suitable solution for the arid and semi-arid regions. The current paper discusses a comparative Life Cycle Analysis (LCA) of the standalone PV and PV/T systems coupled with EWHE cooling for the conditions of Pilani, Rajasthan, India. The main purpose of the study is to evaluate environmental performance analysis for forced cooling (PV/T+EWHE). Environmental performance of the system was evaluated through cradle-to-grave LCA which was carried out by using Umberto NXT software. The life cycle assessment showed that PV, PV/T and EWHE devices consumes large amount of energy during fabrication and installation process. It was also found out that PV/T+EWHE system has huge environmental impacts, in various midpoint and endpoint impact categories, as compared to normal PV system. But on the other hand, the electrical energy performance was better for PV/T+EWHE system as compared to normal PV system. Finally, it was concluded that, large PV/T+EWHE based power plants would be more sustainable in terms of environmental and energy performance.