Deep seawater cooling and desalination: Combining seawater air conditioning and desalination

In tropical climates, the energy consumed by heating, ventilation and air conditioning can exceed 50% of the total energy consumption of a building. The demand for cooling is rising steadily, driven by global warming and rapidly increasing living standards in developing economies. In addition, there is a rise in water demand due to population increase, life quality, and global warming. Coastal areas with narrow continental shelves are the perfect site for implementing Seawater Air Conditioning (SWAC), a renewable and low CO2 emission cooling process. This article proposes the combination of SWAC and reverse osmosis (RO) desalination with the objective of providing desalinated cold water for integrated water supply and cooling services. This combination was named Deep Seawater Cooling and Desalination (DSCD). It was found that DSCD can supply 49 MWt of cooling and 1 m3/s of water simultaneously with an electricity consumption of 12 MWe. DSCD has several benefits compared to SWAC and RO individually, such as in how the cooling service and water supply are delivered together, reducing distribution costs. A case study was performed in Malé, Maldives. It shows that the technology has substantial potential to contribute to the sustainable development of tropical islands.