Analysis of Accelerated Damp Heat Test for Degradation Analysis and Recovery Method of Photovoltaic Module
Muhammad Aleem Zahid, Hasnain Yousuf, Matheus Rabelo, Sung Bae Cho, Yeon Won Yang, Eun‐Chel Cho, Junsin Yi
Abstract
Conventional damp heat (DH) tests conducted at 85 °C and 85% relative humidity (RH) for module degradation cannot reproduce outdoor failures in a short time and it may take up to 4000 h to reproduce multienvironmental stress values. Therefore, an accelerated DH test for photovoltaic (PV) modules is proposed, in which temperatures up to 120 °C are applied to accelerate the degradation mechanism while keeping the humidity fixed at 85%RH and module performance and electroluminescence images are investigated. The environmental stress detected after 600 h at 120 °C/85%RH is comparable with the results of the DH test recorded at 85 °C/85%RH for ≈5000 h. Moreover, the power drop by replacing the backsheet/ethylenevinyl acetate (EVA) and backsheet/EVA/solar cell for one cell area in the PV module after 1000 h DH test at 85 °C and 85%RH is mitigated. After replacing the EVA and backsheet of one cell from the minimodule, a power recovery of 1.6% is achieved. By replacing the backsheet, EVA, and one solar cell from the minimodule, a power recovery of 1.9% is achieved. This analysis indicates that instead of replacing the complete module, it is possible to replace the damaged part of the module.