Abstract

The physical and chemical properties of the encapsulation material define the long term stability of the module, its sensitivity to corrosion and potential induced degradation (PID) and the cell to module losses (CTM). Alternative materials to EVA do offer a possibility to increase the volume resistivity hence the stability against PID effect, better light transmissivity and enhanced stability during climatic testing. The paper investigated the performance of a newly developed encapsulation material, so called polyolefin elastomer (POE), on module level and compared it to the standard EVA material. For this we performed an investigation during damp heat (DH) testing for ribbons soldered or connected by means of conductive gluing to the solar cells. Further tests included extended humidity freeze (HF), a long-term PID, determination of cell to module losses for standard crystalline solar cells as well as IBC Zebra cells and the stability during thermo-cycling (TC). After 4400 hours of DH and HF40 test neither discoloration nor any larger power losses were found. The results after TC300 confirmed a superior performance for POE. We further found that samples with POE material show significantly less PID degradation and reduced CTM losses if compared to samples comprising EVA as encapsulation material.