Comparative degradation analysis of different photovoltaic technologies on experimentally simulated water bodies and estimation of evaporation loss reduction

摘要

Degradation of photovoltaic (PV) systems on water bodies can be matter of serious concern due to high humid environmental conditions above water surface as compared with land surface. The primary objective of this study is to assess the reliability of various PV technologies for megawatt-scale installations by analyzing their degradation on water bodies. An experimental study has been performed for 13 months on three commercially available PV technologies, namely, multicrystalline-Si (m-Si), heterojunction intrinsic thin layer (HIT), and cadmium telluride (CdTe). Degradation of these PV technologies on water and comparison of their degradation with respective land-mounted PV technologies have been presented. Various approaches have been implemented for degradation analysis. The degradation in electrical parameters of all PV modules has been measured. Also, a mathematical PV model has been developed to analyze the internal parameters degradation in different PV technologies. Moreover, thermal imaging has been conducted to distinguish various defects in all PV modules. Evaporation reduction is a significant aspect of water-mounted PV systems, and thus, analytical model to estimate evaporation has been developed and experimentally validated in this study. The HIT PV technology is observed to be degrading almost at the same rate of about 0.50% on both water and land surfaces, whereas degradation of water-mounted m-Si module has been found 1.32% which is significantly higher than the corresponding land-mounted module which has degradation of 0.93%. Degradation in CdTe modules is 1.68% on water, which is marginally higher than corresponding land-based module that has degradation of 1.41%.