Achieving 100% desalination with solar power in South Africa

Africa’s first 100% solar-powered desalination plant has produced 10 ML of fresh drinking water—with help from Danfoss APP pumps and iSave energy-recovery technology.

Developed by Mascara Renewable Water and Turnkey Water Solutions, the OSMOSUN® unit at Witsand—in South Africa’s Southern Cape—is powered solely by photovoltaics (PVs) producing 73kWh/day.

Taking water from the sea, the plant provides people in the historically drought-prone region with up to 100,000 L of safe, drinkable water per day.

The seawater reverse osmosis (SWRO) conversion process uses a highly efficient Danfoss APP pump to force water through a desalination membrane under high pressure. The water’s kinetic energy then drives the iSave 21 Plus energy recovery device.

Specifically developed for SWRO applications, the Danfoss iSave 21 Plus recovers kinetic energy that would otherwise be lost and returns it to the plant. The APP pump’s simple construction also makes it compact—with very little maintenance required—ideal for remote sites. What’s more, it’s oil free, so the risk of unplanned downtime is significantly reduced and there’s zero potential for water contamination.

Mascara’s OSMOSUN® system is already proven in other parts of the world (we have a more detailed story about its PV-powered SWRO plant in Abu Dhabi). At full capacity, it can produce approximately 300,000 L/day, using 400 m2 of PV panels.

Source: Danfoss