Most areas in South Africa average more than 2 500 hours of sunshine per year, and average solar-radiation levels range between 4.5 and 6.5kWh/m2 in one day. The southern African region, and in fact the whole of Africa, has sunshine all year round. The annual 24-hour global solar radiation average is about 220 W/m2 for South Africa, compared with about 150 W/m2 for parts of the USA, and about 100 W/m2 for Europe and the United Kingdom. This makes South Africa's local resource one of the highest in the world.

Solar thermal energy is used for different applications at vastly differing scales. These applications always employ the use of a solar collector to harness the heat of the sun. This is different from solar photovoltaic collectors or PV cells, which convert solar energy directly into electricity. Low and medium-temperature collectors are usually flat and consist of coiled tubes of a highly conductive material, such as copper, or evacuated, water-filled glass tubes that convert radiation from the sun into heat. They are usually used for heating water for residential and commercial use. High temperature collectors concentrate sunlight using mirrors or lenses and are generally used for creating heat to generate electricity.

On a large scale, South Africa's main power utility, ESKOM, is considering the feasibility of building a concentrating solar power plant (CSP) in the Northern Cape Province.

On the domestic scale, South Africa has embarked on an ambitious solar water heating (SWH) programme. Solar cooking and solar drying are other applications of solar thermal energy utilisation.