Pathways Towards Advanced PID Resistance of 1500V

31st European Photovoltaic Solar Energy Conference and Exhibition; 15-19
The recent technological shift towards photovoltaic (PV) systems operating at voltages as high as 1500 Vdc combined with the trend towards transformerless inverters in order to reduce the system complexity and cost is increasing the risk of Potential-induced-degradation (PID) in contemporary PV modules. It is well known in the PV industry that PID phenomenon is one of the major technical challenges with an incomplete fundamental understanding. To minimize the risk of PID there are several approaches at different levels of the PV cell and module laminate (e.g. cell anti reflective coating, encapsulants, etc.). Yingli is going beyond current standards and is striving for PID resistance for voltages of up to 1500Vdc, without sacrificing power output to deliver a reliable, manufactural, and cost-effective solution to the problem. In this work, we study the potential of resolving PID on the cell-level by modifying the Silicon Nitride (SiNx) anti-reflection coating (ARC) and compare it to a module-level approach using ionomer encapsulants. We identified SiNx coatings that yield PID resistance at 1000 Vdc, albeit at cost of power loss. Ionomers show full suppression of PID at no initial power loss, which was verified by an independent testing lab. In addition, we demonstrated that modules made with ionomer film surpassed standard reliability tests. Results of PID exposure tests at 1500Vdc will be presented.