Estimation of solar irradiation based on multiple stepwise regression

Solar irradiation is a vital parameter of solar energy application, which is used to estimate the photovoltaic power station output. The network of stations measuring the solar irradiation data is sparse in many developing countries. In this paper, historical data of past nine years are employed to establish and validate the solar irradiation models. Utilizing the regression analysis, the solar irradiation models on meteorological parameters such as sunshine duration, temperature and relative humidity are established. Validation results indicate that the proposed models can efficiently calculate the solar irradiation.