The Axarquía reservoir is still very low despite the recent rain. / ñito salas

Floating solar panels will help proposed La Viñuela desalination plant be more environmentally friendly

They will keep energy costs down while, meanwhile, the brine produced by the desalination process will be sold for other purposes instead of being treated as waste

IGNACIO LILLO MALAGA.

There are two main concerns about seawater desalination plants: the high energy costs involved and the by-product they produce, the brine, a contaminant which older types of plant usually discharge into the sea. However, for the project planned by Trops, the Institute of Domotics and Energy Efficiency at Malaga university and the Cobra Group, neither of these problems exist.

The planned desalination plant would be powered by floating solar panels on La Viñuela reservoir, which will be able to produce 250 megawatts – enough not only for the desalination system and its derivatives but companies in the area as well.

And with regard to the brine, this will no longer be considered waste but will be sold as a resource with multiple uses. Those behind the project estimate that two million euros a year could be earned from this material.

Uses for brine

Brine can be used to produce green hydrogen, chlorine and other chemical products, manganese and other minerals. To do so it needs a great deal of electricity, but Enrique Colilles, the general manager of Trops, says that will be solved by using solar panels. He says companies have already expressed an interest in purchasing the entire production of brine, and that would solve the problem of sea pollution.

The water obtained from the plant will be highly filtered so it can be consumed directly, needing no more treatment than any other water. “It will have the quality of rain water; it will be added to La Viñuela reservoir and will use the same system for irrigation as at present,” Colilles explained, saying that this will avoid having to construct new pipelines.

The reservoir will always be full

The electricity from the solar panels will pump the water from the plant to the reservoir, which will always be full. The water produced will cost very little: between 20 and 30 cents per cubic metre.

The desalination plant is expected to cost 144 million euros and will produce between 20 and 40 cubic hectometres of water, enough for some to be exported to areas which need more. The plant could be built within one year and producing water just three months after the relevant permits are obtained.