Analysis of in situ performance of rooftop PV system in Seoul, South Korea

Abstract

This paper presents a study of a 98.1 kW-PV system facing south at an inclined angle of 15º on the roof of a university building in Seoul, South Korea (latitude 37.63° N and longitude 127.1° E). The system performance was analyzed for 2 years from Sep. 2015 to Aug. 2017. The average electrical power output was 0.59 kWh/(m2·day) with a 16.9% average annual efficiency for the 1st year which further decreased to 0.58 kWh/(m2·day) with average annual efficiency of 17.6% in the 2nd year. The annual irradiance was 3.50 kWh/(m2·day) for the 1st year and 3.31 kWh/(m2·day) for the 2nd year with a total annual output generation of 105.4 MWh and 103.5 MWh, respectively. Average daily power generations were 2.93 and 2.89 kWh/(kWp·day) for 2 years, respectively, with an annual performance ratio range of 80 ~ 90%. Predicted module temperatures show a good correlation with measured temperatures. Predicted and measured output values show a strong correlation. During the 1st year at a maximum module temperature of 60ºC, power output loss was found to be 13.3%, while in the 2nd year at a maximum module temperature of 57ºC, the power output loss observed was 12.2%.