Power stabilization of crystalline PV modules

36th European Photovoltaic Solar Energy Conference and Exhibition; 977-982
Power output results of module measurements performed in independent laboratories often appear lower than those indicated on the label. The reason for this effect is that several factors that may affect a PV module’s power output, are not taken into account. PV modules made of crystalline silicon solar cells suffer an initial slight loss in peak power, an effect known as “light induced power stabilization” [1,2]. Many module producers know this effect and have this light induced degradation (LID) included in their product guarantee. Before starting the IEC reliability tests, PV modules need to show a stable output. Which is why they must be exposed to sunlight or a solar simulator at over 20kWh/m2. This power stabilization test is also compulsory according to the IEC 61215 standard on certification of photovoltaic modules [3]. When different combinations of module materials are tested for durability in, for instance, damp heat (DH) and thermal cycle (TC) testing, stable solar cells are needed as a reference to distinguish between the various effects of the materials. In the performed experiments, durability testing results with and without light soaking (40kWh) were compared.