Could Solar-powered Desalination Solve California's Water Supply Problem?

California is suffering through its worst drought in decades, and it has gotten so bad that officials announced that 17 communities across the state are in danger of running out of water within 60 to 120 days. But what if the solution to California’s water crisis is as simple as sunlight – a resource the state has in abundance? That’s exactly what California-based startup WaterFX is proposing with its solar-powered desalination system. Renewable desalination could solve water scarcity issues not just in California but in other drought-stricken and desertified areas across the world.

WaterFX‘s system cleans water with a Concentrated Solar Still (CSS), which collects the sun’s thermal energy and transfers it through pipes filled with heat transfer fluid to a heat pump. The heat is then used for the distillation process, which evaporates freshwater out of the saltwater source. The condensate is then recovered as pure, fresh H2O. A thermal storage system holds excess heat for the times when the sun isn’t shining.

“If we roll out the technology … we could produce 8% of all the water used in California, with just the land that was fallowed during the last drought,” WaterFX Founder and Chairman Aaron Mandell recently told Forbes Magazine. “That’s enough water for over 7M acres of irrigated farmland. You would begin to change the economics and change the course of how water is used. The whole idea is to wean the State off of the Central Aqueduct and become water independent. The current system is unsustainable and unreliable.”

However solar desalination systems are not without their challenges – it takes a lot of energy to suck up large quantities of ocean water, and the process can capture local marine life as well. There’s also the issue of solar desalination’s byproduct – a salty sludge that can harm ecosystems if it’s pumped back into the ocean.

Other parts of the world working on renewable desalination include
South Australia, where Sundrop Farms has installed a desalination plant near Port Augusta;
Qatar, where the Sahara Forest Project is experimenting with a pilot system; and
Saudi Arabia, where there are plans to build a solar-powered plant in Al-Khafji. Saudi Arabia currently uses the equivalent of around 300,000 barrels of crude oil a day for its desalination plants, so switching from fossil fuels to renewable energy could have a huge positive impact on climate change and sustainability.

“What we are trying to do is to develop a model that can be replicated. The problems in California are identical to those in many parts of the world. China is depending on delicate river systems to provide water for all types of economic growth that will not be sustainable. We could also do this in Saudi Arabia – they use an enormous amount of oil for water consumption, to evaporate or move water around the country,” said Mandell.

+ WaterFX

Via The Guardian

Images via WaterFX

ORIGINAL: Inhabitat

by Josh Marks, 

02/27/14