Precise outdoor PV performance measurements at various irradiance levels

Precise characterization of the outdoor PV module performance at various irradiance and temperature conditions are investigated. Recently proposed I-V curve measurement conditions, such as the sweep time within 0.2 s etc., enabled highly reproducible outdoor performance characterization even under partly sunny days, where the temporal variation of the solar irradiance is significant. The outdoor I-V measurement opportunity is significantly increased by enabling the measurement under unstable irradiance. The PV modules experience wider range of combinations of irradiance and temperature on a partly sunny days than on clear sunny days. Therefore, performance characterization over wide range of irradiance and temperature within a short period of time in one day is possible on partly sunny days.