Estimation of module temperature for water-based photovoltaic systems

Abstract

Estimation of module temperature is important for the assessment of performance and reliability of photovoltaic (PV) modules. The objective of the present work is to develop a simple model for estimation of module temperature of water-based PV systems. In this paper, a new approach has been proposed to incorporate the effect of water on PV module temperature. PV modules experience differential heat exchange from their front and rear sides under the influence of water. Therefore, in the proposed approach, separate thermal loss coefficients have been calculated for the front and rear sides of PV modules. The experimentally measured data of a complete year has been utilized to determine the thermal loss coefficients of front and rear sides of PV modules. These coefficients have been used along with PV module technology parameters for predicting module temperature. The ratio of front and rear side thermal loss coefficient of hetro-junction with intrinsic thin layer (HIT), multi-crysalline Silicon (mc-Si), and Cadmium Telluride (CdTe) PV technologies is found to be 0.537, 0.556, and 0.363, respectively. The developed model has been validated using an experimental setup comprising of three different PV module technologies. The mean bias error and root mean square error for the developed model have been found to be less than 0.5 °C and approximately 3 °C, respectively. This shows that the developed model is accurate enough and consistent for temperature estimation of different PV module technologies on water bodies.