Solar thermal

Solar thermal, the use of heat from the sun, differs from solar photovoltaic (PV) technology as shown in the diagram below. Solar PV uses solar PV cells to turn light from the sun into electricity. Solar thermal systems use solar collectors to get useful heat from the sun. Linked to these key differences is the fact that the system efficiencies differ with solar PV systems only able to achieve a system efficiency of ± 20% while solar thermal systems are able to achieve system efficiencies of ± 50%.

pv vs thermal v3

Opportunities: Fast facts

  • Over 50% of final energy demand is for heat.
  • Low temperature applications are most economical for solar thermal.
  • There is an estimated potential for solar thermal installation of between 425 000 m2 and 3 758 000 m2 in South Africa's agri-processing sector representing between 111 000 and 943 000 tonnes of CO2e emissions saving potential per annum.
  • Solar thermal can reduce energy bills, ensure compliance with sustainability mandates and reduce companies' carbon footprints, given that most (79%) of agri-processing sector's energy demand is for low temperature heat, which solar thermal provides most economically.

Support programmes (non-GreenCape)

  • SOLTRAIN provides a wide range of support from training of installers to subsidised installations to serve as demonstrations systems.
  • The South African National Energy Development Institute (SANEDI) and the Southern African-German Chamber of Commerce and Industry (SAGCCI) have teamed up for the international ‘Solar Payback’ project, which aims to increase the use of solar thermal energy in industrial processes.

GreenCape's work in the space

As an institution supporting the growth of the green economy in the Western Cape, GreenCape has a range of activities that help support the solar thermal market directly and indirectly in collaboration with a range of institutions. 

GreenCape also works actively to encourage energy efficiency through a range of industry events highlighting key policy changes such as the building standards as well through the development of the energy efficiency market intelligence report.

Key reading

For other related tools, resources and information see the Library . 

News and events

GreenCape's Energy Programme honoured at Vision 2030 Awards

GreenCape's Energy Programme has been honoured by being chosen as a finalist for the Vision 2030 awards. Read more

SOLTRAIN course on solar heat for industrial applications 22-24 November

SOLTRAIN is presenting its second specialised course on "solar heat for industrial application". Read more


Joint report on Industrial scale solar heat in South Africa released

Working with the World Wildlife Fund (WWF) and the Centre for Renewable and Sustainable Energy Studies (CRSES) we have published a technical report on Industrial scale solar heat in South... Read more

REN21's Global Renewable Global Futures Report 2017

GreenCape, on an annual basis, contributes to global efforts to make known possibilities through advances of the green economy. Read more