Analysis of the temperature models for the evaluation of global solar radiation in the coastal and interior regions of South Africa.
Presented by Dr. Eric MALUTA on 11 Jul 2014 from 11:10 to 11:30
Type: Oral Presentation
Track: Track F - Applied Physics
Solar radiation is a crucial parameter in designing solar power devices, installation of solar technologies systems and studying land surface-processes. These data are usually not available for most areas due to the lack of weather stations especially in developing countries. Estimation of global solar radiation (H) from the daily range of air temperature (ΔT) offers an important alternative in the absence of measured H or sunshine duration because of the wide availability of air temperature data. Hargreaves and Samani developed a temperature based model using maximum (Tmax) and minimum (Tmin) temperature data to estimate the global solar radiation, the model is given as, H=H_0 (k_r √∆T), where H0 is the extra-terrestrial radiation kr is the empirical coefficient and ∆T = Tmax – Tmin. They further proposed that the kr values differ from coastal and inland regions by 0.19 and 0.16 respectively. In the current study the validation of kr value has been performed for the coastal and interior regions of South Africa. The average yearly mean bias error (MBE) and root mean square error (RMSE) have been calculated for different stations over the period of five years. The results will be discussed in the presentation.