Typical water purification is an expensive and complicated process, but a new solar-powered version could produce clean water for crops in California’s Central Valley
There are billions of gallons of water in the Central Valley, actually, but there’s a problem. The water is contaminated with toxic levels of salt, selenium, and other heavy metals that wash down from the Panoche foothills. Farmers in the Central Valley need plenty of freshwater to keep saltwater at bay in their fields, but freshwater provided by the Central Valley Project is expensive, at $280 per acre-foot. The water purification project these farmers rely on is also unreliable. In 2012, for example, farmers received just 40% of their allocation, and in 2013 just 20%. For 2014, they will receive no water at all.
Farmers in the California Central Valley have already abandoned over 100,000 acres of farmland, and no irrigation water for 2014 means that hundreds of thousands more acres will become too toxic to grow crops. The WaterFX water purification project, a solar-powered trial plant built in Firebaugh, California, could solve that problem. Instead of using solar power to run electric pumps and filtration systems, the WaterFX plant uses concentrated solar power to heat a pipe filled with oil. The oil, by temperature differential, flows through piping to radiators, where water flashes into steam, leaving salt and other contaminants behind. The steam condenses into distilled water, cleaner than some bottled waters.
The WaterFX solar-powered water purification pilot plant produced just 14,000 gallons of distilled water per day, but the commercial version of the plant is much larger. Set to be built later this year on 31 acres of land, the WaterFX plant will produce 2.7 million per day, possibly more, which is more water than needed for irrigation. Aside from being perfectly clean, WaterFX doesn’t need to pipe in water from afar, using the contaminated water right there in the ground. Additionally, because of the overproduction expected, WaterFX will be able to distribute water much farther than the Central Valley.