Abstract

Solar radiation is an important energy source for mankind. Accurate data of solar radiation levels for a particular location is vital for optimum operation of solar energy transducers such as photovoltaic cells and solar thermal collectors. In this work, it is shown a linear relationship exist between monthly average temperatures and solar radiation in Swaziland. The correlation has been utilized to develop two mathematical models for the estimation of solar radiation: one from the measured monthly average temperatures and the other from the square-root of the difference between measured maximum and minimum monthly average temperatures. Both models fit the data well and can be applied to estimate solar radiation in other parts of the region.

Key words: Solar energy, solar radiation, climatic data, solar radiation estimation.