Intercomparison measurement of crystalline silicon PV modules in test laboratories of China

To evaluate measurement deviation of c-Si PV modules electrical performance among test laboratories in China, eight testing institutions participated in the interlaboratory comparison test of I-V characteristic measurement of c-Si PV modules. This paper reveals that a maximum ±2% deviation of short circuit current value between each laboratory measurement value and average value. Maximum power values measured in majority of the participating labs are within the range of about ±1.5%. Major cause of the difference in peak power was short circuit current. The differences in FF and Voc are almost negligible compared with short circuit current. Considering solar simulator measuring method is adopted in all laboratories, the traceability of reference PV module or cell is the most important factor to cause deviation of short circuit current. The intercomparison measurement procedure also contains electroluminescence testing before and after the shipment of modules under test to improve conformity of the PV measurement technology, which is effective approaches to verify the stability of modules and the influences of vibration during shipment.