Solar irradiance estimation based on photovoltaic module short circuit current measurement

This paper presents the estimation method of solar irradiance in W/m² based on the short circuit current output produce by the photovoltaic module. The proposed solar irradiance estimation method is derived using photovoltaic mathematical model. Therefore, photovoltaic module modeling is required to develop the proposed estimation method. The modeling includes the identification of photovoltaic module diode ideality factor using recursive iteration and series resistance identification using photovoltaic model equation. The reminding modeling parameters can be obtained from the given photovoltaic module manufacturer datasheet. With all the required parameters in place the solar irradiance can be estimated using equation derived from the photovoltaic model. The proposed solar irradiance estimation method is evaluated using a 80W 36 cells polycrystalline photovoltaic module in the field and the results are validated with a World Meteorological Organization certified second class pyranometer. This paper demonstrates that the solar irradiance can be estimated by the short circuit current output measured from the photovoltaic module with acceptable accuracy. This contributes to the elimination of the installation of expensive pyranometer.