The world’s first desalination unit using waste heat from a power generator with membrane distillation has started up on Guhli island in the Maldives in the Indian Ocean.
The 10 m³/d system was developed by the local power company STELCO in a joint venture with the UK’s Aquiva Foundation. It is providing water for about 1,200 inhabitants, whose only other water source is seasonal rain, to use for drinking, cooking and hygienic purposes.
The desalination plant taps into the cooling cycle of local diesel generators to retrieve the thermal heat that is otherwise wasted into the air. This waste heat of about 85°C drives a desalination process under vacuum using the membrane distillation modules of the German/Singaporean company memsys Clearwater Pte Ltd.
The distillate is then mineralized using local coral sand for a good Maldivian taste. It is distributed under the brand “Aquiva fushi” – fushi standing for the pure island taste created by coral sand in the mineralization process.
Florian Bollen, CEO of the Aquiva Foundation, noted that, “This is a good example of how water problems can be solved sustainably on a local level, even in situations where no sweet water is available. We are already working to apply this concept to many of the 200 inhabited islands of the Maldives, a number of resort islands plus other nations.”
The foundation employs a micro-finance approach, providing the technology, training and support needed to generate safe water for personal, industrial and agricultural use. Both memsys and Aquaver of the Netherlands support the Aquiva Foundation by providing their vacuum multi-effect membrane distillation technology and plants on an “at-cost” basis.