Compact, energy-efficient SWRO strengthens Cape Town’s water resilience

Against the backdrop of Cape Town’s long-term water shortages, PROXA’s customer, the owners of the celebrated V&A Waterfront in the city’s harbour district, wanted to increase their resilience to water scarcity. Because the property has access to the sea, SWRO was a logical choice. However, the property’s unique situation placed special demands on the SWRO plant’s design. 

According to Derick Coetzee, Sales Manager at Marsi Water, not only would plant capacity have to be big enough to cover all water needs of the property’s hotel, shops, restaurants and other businesses. It must also be compact as possible because the space it takes up in the attractive location could otherwise be leased. Finally, in line with the property owners’ decarbonization policies, the entire property would have to operate at net zero no later than 2030 – so the SWRO plant would have to be as energy efficient as possible.

When PROXA’s engineers approached Marsi Water to discuss possible component choices, Coetzee was not in doubt that the Danfoss lineup of APP pumps and iSave energy recovery devices were strong contenders. “The combination of Danfoss’ best-in-class energy efficiency and very compact footprint is ideal for a project of this kind,” he explains. “Not only could PROXA maximize water production per cubic meter of space used. They could also minimize electricity consumption per cubic meter of water produced.”

To further boost resiliency, PROXA engineers decided on a two-train design so that even if one train was down for maintenance or repairs, the other would still produce water. “This multi-train design gives both plant operators and owners increased flexibility,” says Coetzee. “In addition to redundancy of the most critical components, it also simplifies plant expansion should this be necessary in the future. Adding another train to an existing plant is much easier than redoing the entire plant.”

Each of the plant’s two trains comprises one APP86 high-pressure pump and two iSave 50 ERDs.

The plant was commissioned in October, 2024, and operations have thus far been trouble free.

According to Regardt de Swardt, Project Manager for PROXA, “Danfoss and Marsi Water provided impeccable service during both the design review and commissioning phases. Their international commissioning team provided initial training, and their service team provides ongoing support to the PROXA Operations & Maintenance team during the 10-year operations contract.”

“We’re very pleased with Danfoss’ cooperation on this project,” says Coetzee. “and we look forward to the possible expansion of this plant, something that the V&A Waterfront and PROXA have already discussed.”