Nereid – South Africa

Swiss Partners

Nereid SA, Geneva
Huy Ton Tha

Local Partner

Project Type:

Pilot project


Energy efficiency


South Africa

Project Status:


Project Start:


End of Project:




Swiss Contribution

Since 2015, Nereid has developed know-how in water purification by working with various Swiss organizations such as the University of Geneva (UNIGE), the Haute École du Paysage, d’Ingénierie et d’Architecture Geneva (HES-SO HEPIA), the Geneva State Utility Company (SIG) and the Geneva Special Waste Treatment Center (CTDS).


Through a combination of circumstances, including climate change, economic and demographic growth, the Western Cape’s fresh water supply is inadequate to meet the existing demand. Addressing this issue, the Nereid multi-effect humidification (MEH) desalination technology combines the use of solar thermal energy and a zero liquid discharge system, where minerals contained in seawater are crystallized then extracted from the system. Nereid intends to set up a pilot unit in the Western Cape with a capacity of 15 m3/day. Therefore, the objective in field testing is to demonstrate that the Nereid design’s more efficient heat exchanger can produce an equivalent fresh water quantity with 40x less exchange surface than conventional MEH technology; hence, dramatically reducing costs and increasing energy efficiency.


The system was assembled in Switzerland, and the first trials were carried out in the Mediterranean, in the south of France. Minor adjustments were made to optimise operation. The installation is due to be shipped to South Africa shortly. The project has been extended by a few months due to delays caused by the COVID-19 pandemic.