Solar desalination

Solar-powered desalination in Chile proves successful

A test model in one arid valley in Northern Chile is showing how the sun might be the key to agricultural expansion.

Monday, August 26, 2013  
The desalination plant. Photo by Fundación Chile. The desalination plant. Photo by Fundación Chile.


At first glance, Chile’s desert north may not seem like the kind of place ready for an agricultural boom. That first glance, though, is wrong. The region is home to farms producing everything from grapes to papaya, all of them taking advantage of the long growing season that helps to make Chile one of the world’s chief exporters of fresh produce.

One limiting factor is water — the region is home to the driest desert in the world, the Atacama. Much of the water available contains high levels of salt and boron picked up from the desert flats. Even then, the agricultural industry also has to compete with a booming mining sector and the growth of northern cities.

Those problems may soon be alleviated thanks to a low-cost solution currently being tested in the Arica Region’s Lluta Valley. A demonstration model of a US$210,000 desalination plant there has been successfully removing the salt and boron from brackish desert water since March, and doing so without putting a strain on the established power grid. The results have been so good, in fact, that the project’s organizers hope to begin commercializing the model for use across Northern Chile.

That’s possible because of Chile’s immense solar resources. It’s estimated that the solar energy potential in the Atacama Desert, when combined with wave and tidal reserves from the Andean nation’s lengthy coast, makes up the largest non-conventional renewable energy resource on the planet. The facility uses solar panels to completely power a desalination plant using cutting-edge membrane separation technology to remove the salts and produce usable water.

“The benefit lies not only in the new water technology, but also the low energy consumption," Carolina Cuevas Gutierrez, the project manager, told the industry publication Water World. “As we know, energy represents the biggest cost in any technology. Using today's solar technology, we can produce excellent quality water, and the next step is to apply this to further agricultural production."

The facility generates all the electricity it needs to operate, eliminating one of the main drawbacks to desalination — the strain it puts on electrical grids.

The project’s relatively low cost, ease of construction and self-sufficient energy profile means it may soon prove a viable option to provide the water needed for agricultural expansion. The project is funded by the government-backed Fundación Chile.