Solar power and desalination have typically been employed separately, with solar power converting the sun’s energy into electricity and desalination removing unwanted minerals from saltwater so it can be used for drinking or agriculture. WaterFX, a San Francisco-based water producer, has found a way to merge the two technologies and plans to build California’s first commercial solar desalination plant. The plant will be located in the Central Valley, where sunshine is plentiful, and will ultimately generate up to 5,000 acre-feet, or 1.6 billion gallons, of clean water per year — enough water for 10,000 homes or 2,000 acres of cropland. It will turn unusable irrigation water from a 7,000-acre drainage area into freshwater by removing unwanted mineral and salts.
The system uses heat generated from parabolic solar panels to evaporate clean water out of the original source water. The condensate is then recovered as pure water at over 90 percent efficiency. When the sun isn’t shining, thermal heat storage allows the process to continue.
The implications are far-reaching. In a state that has endured 4 years of drought, agriculture accounts for 80 percent of water used and results in an estimated one million acre-feet of irrigation drainage that could be treated and reused if solar desalination catches on.
For more information, see Climate Progress “Have You Heard of Solar Desalination?”.
Category: Cool Tech