PV MODULE HOT SPOT INVESTIGATION BASED ON 1GW WORLDWIDE DATABASE

摘要

Module hot spot is the crucial reliability issue for massive PV deployment as a major renewable electricity source. We carry out the statistic analysis from 3.8 million modules over 1GW capacity during the first five-year system operation. There are total 49 faulty hot spot modules spreading out in 9 of over 1,250 global project sites with 12.9ppm failure rate. Around 73.5% of failure contribution is due to system install sector. Most faults due to module and cell sector occur within first two year operation. Main failure modes include hot cell, burning from cell edge and burnt backsheet, while 69.4% portion of the root cause results from cell cracking induced by frame damage during system construction. Other root causes are also investigated by detail inspection, and the correlation is established between analysis result and failure mode. In cell level, experiments validate that increasing shunt resistance and reducing reversed current effectively suppress module hot spot temperature. In addition, suggestion for preventing hot spot risk is provided for each sector respectively through whole PV value chain.