Floating, high-capacity desalting islands on renewable multi-energy supply

The concept DESIRES® is presented as a floating, but moored, DESalting Island on Renewable multi-Energy Supply. It is estimated to produce 5–500 Mm3/y of high quality fresh water from seawater, at the costs of US$ 0.88– 1.32/m3. This is achieved by using: (a) an artificial, floating island 10–100 km from the shore, 0.06–0.65 km2 in size with hexagonal shape, 0.1–1 km in diameter and 20 m deep; (b) a high-yield combination of many, renewable energy sources (eolian, solar, tidal, wave and hydrothermal gradient); (c) the use of a huge storage reservoir aboard for stabilisation and coping with fluctuations in energy supply and water demand; (d) the use of peak energy supply (during storm events) to pump stored fresh water to land and to pressurize this water to generate hydro-power on land; (d) reverse osmosis; and (e) intelligent technological solutions to reduce energy consumption and maintenance. In this way, a contribution is made to solve water scarcity problems without aggravating the mondial issue of climate change. Additional advantages of DESIRES® are: modularity in construction, easy brine disposal, no optical nor acoustic pollution (on land), and use as a weather and oceanic monitoring station.

Preliminary calculations indicate that the production costs of fresh drinking water from seawater by desalination on huge floating islands through renewable multi-energy supply are invitingly low (US$ 0.88–1.32/m3). This is close to prices using fossile fuels, but with the strong advantages of being without adverse environmental effects (including climate change). Besides, really large quantities of water can already be produced by only one island: a hexagonal island of 0.06–0.65 km2, 0.1–1 km in diameter can produce 5–500 Mm3/y, enough to provide a city with about 105–107 inhabitants.