Performance ratio measurement method of photovoltaic modules under natural sunlight condition

Photovoltaic module is the key photo-electric conversion product in renewable energy field. To evaluate photovoltaic module electrical performance accurately, module performance ratio parameter is presented in this paper. On-site experiment for performance ratio is introduced and illustrated for performance ratio calculation and assessment of modules under natural outdoor condition. Compared with peak power and efficiency parameters of module, the performance ratio is more accurate and suitable for rating photovoltaic module electrical performance over long time period.