Quantifying the global solar radiation received in Pietermaritzburg, KwaZulu-Natal to motivate the consumption of solar technologies

Abstract

In South Africa, power outages and scheduled load shedding are common practices in a bid to safeguard power resources. With the increase in cost of conventional energy sources, and the depletion of fossil fuels, attempts to use renewable resources to their full potential are underway. South Africa and in particular Pietermaritzburg receives sunshine throughout the year, making it suitable for harnessing solar power. In this work we estimate the amount of Global Solar Radiation (GSR) received in Pietermaritzburg which is the capital of the KwaZulu-Natal province. An air temperature model (Hargreaves-Samani) is used to approximate the GSR received in Bisley in comparison to measured data obtained from the ARC, for a period of one calendar year (July 2014 – June 2015). We proceed to apply the Angstrom-Prescott model to evaluate the competence of the initial prediction method. The primary aim of this study is to validate the efficiency and accuracy of the above-mentioned forecasting models, for areas within close proximity. Our results compare fairly well with the observed data provided by the ARC. Both models prove to sufficiently estimate the amount of GSR incident in Bisley. The deviations from the actual measured values suggest that a model which incorporates both variables may improve the accuracy of GSR estimations. The use of comprehensive prediction and forecasting models will allow for optimal placement of solar technologies for the harnessing of GSR within Pietermaritzburg. Though Pietermaritzburg may not be suitable for large scale solar power plants, the employment of solar panels in both industrial and residential areas will contribute greatly to a decrease in demand of grid electricity.

Keywords

• load shedding
• global solar radiation
• photovoltaic technologies
• air temperature model
• angstrom-prescott model
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