Estimation of Monthly Average Daily Solar Radiation from Meteorological Parameters: Sunshine Hours and Measured Temperature in Tepi, Ethiopia

In this study, several equations were considered to estimate monthly average daily solar radiation from meteorological parameters: Sunshine hours and measured Temperature in Tepi, Ethiopia. These equations include the original Angstrom-Prescott linear regression and modified models (quadratic, polynomial, logarithmic and exponential functions) and temperature based models. The performance of the models was evaluated using the methods of statistical analysis. This study shows that from sunshine hours based models Samuel and Newland models are appropriate for Tepi due to their better statistical model performance analysis. From temperature based models, Chen et al., models fitted the data adequately and can be used to estimate solar radiation from temperature measurement. However, the developed correlation models give better statistical model performance analysis and therefore, it can be recommended that these models are used reasonably well for estimating the solar radiation in Tepi and possibly in its surroundings sites with similar climatic conditions if empirical coefficients are correctly calibrated.