Performance Evaluation and a New Thermal Model for a Photovoltaic-Thermal Water Collector System

A Photovoltaic-thermal (PVT) system is a hybrid solar panel system combining the functionality of solar photovoltaic (PV) and thermal collectors in one system. In Solar PV panel as operating temperature increases, electrical efficiency of panel decreases. In solar PVT panel low temperature fluid, for example water or air is circulated through the heat exchanger placed on back side of PV panel to extract heat from panel and then that heat energy to be utilized for thermal applications. In this way improvement in electrical efficiency is achieved along with heat energy as a by-product. In this paper, a thermal model of a PVT water collector system has been developed. An analytical expression for solar cell temperature, back surface temperature of tedlar, water temperature and an overall thermal efficiency of water collector system has been derived.