South Africa is an arid country. A “climate independent” solution is desalination. Infinite renewable energy sources could address the implementation of these technologies and the environmental impacts. Recommendations to increase the water-energy-climate security of South Africa are provided in this paper. The main objective was to investigate the requirements and environmental benefits of four energy sources for seawater desalination. Secondary data from published literature was analysed with the “Long-range Energy Alternatives Planning System”, using scenario analysis. This compared the trade-offs between water supply, energy demand and climate change mitigation within a South African context. The four power sources were solar, wind, wave and geothermal. Geothermal was the least practical source for South Africa. The technologies for desalination were reverse osmosis and two thermal technologies (Multiple effect distillation and Multiple/Multi-stage flash distillation). It was concluded from both analyses that the most suitable alternative for desalination, was probably wave powered seawater reverse osmosis. In the Western Cape and KwaZulu-Natal, this could be combined with existing technologies.