Technical, environmental and ranking analysis of using solar heating: A case study in South Africa

Abstract

The process of heating water consumes a lot of energy. In South Africa (SA) up to 40% of household energy consumption is utilized for water heating. In this regard, the use of renewable energies, especially solar, can help reduce the energy crisis in this country. In this study, applying the solar water heaters (SWHs) in home-scale has been explored for the first time, by using climatic information for 21 cities in South Africa. The techno-environmental assessment was performed by TSOL PRO 5.5 on two types of the evacuated tube (ET) and flat plate (FP water heaters). Furthermore, these cities are ranked using GAMS 24.1 and two types of DEA methods. The results indicate the efficiency of evacuated tube SWHs is better than that of flat plate SWHs at all cities and if we use the FP water heater, the average solar fraction is 95.93%, which prevents about 23.5 tons of CO2 emissions annually. These values for ET water heaters are 99.16% and 24.4 tons per year, respectively. For the FP collector, the findings indicate Beaufort West, Mmabatho and Welkom cities are preferable cities in both models, DEA-CCR and DEA-Additive models. © 2022 Elsevier Ltd