prBAS IEC TS 63202-4:2025

IEC TS 63202-4:2022 describes procedures for measuring the light and elevated temperature induced degradation (LETID) of crystalline silicon photovoltaic (PV) cells in simulated sunlight. The requirements for measuring initial light induced degradation (LID) of crystalline silicon PV cells are covered by IEC 63202-1, where LID degradation risk of PV cells under moderate temperature and initial durations within termination criteria of 20 kWh·m^-2 are evaluated. The procedures described in this document are to evaluate the degradation behaviour of PV cells under elevated temperature and longer duration of light irradiation. The procedures described in this document can be used to detect the LETID risks of PV cells [2],[3] and to judge the effectiveness of LETID mitigation measures, e.g. quick test for production monitoring, thus helping improve the energy yield of PV modules.