Pulling moisture out of thin air may be a new technique to combat California drought

The most recent water supply expansion plan for California emphasizes water conservation, wastewater recycling, desalination water production, and stormwater collection. So, here is an analysis by David Hertz on how to pull water out of thin air.

"We're able to generate about 2,000 liters in a 24-hour period," Hertz says.

"Every tree and plant evapo-transpires, so basically is sweating moisture, so all that moisture is in the air at any given time such that there's six times more water than all the rivers. The question is, 'how do we get it?'" Hertz asks.

When warm air encounters a cool surface, condensation happens. On things in your refrigerator or practically every morning, you can see it. Hertz's WeDew system uses that method to produce hundreds of gallons of water per day on 99 acres in Malibu. It does this by turning a movable shipping container into a water generator. Hertz starts by using a gasifier to vaporize 50 pounds of biomass from his farm at temperatures of about 1,400 degrees. The waste gases are put to use in a generator that generates electricity for his residence and charges batteries.

But for water production, hot and humid air is captured, condensed, and filtered.

"Think of it as a tropical rain forest in a box," he says.

The biochar byproduct from the wood is used to replenish the soil. Entirely on renewable energy and at the cost of about half a cent per liter of water created.

"You get the carbon out of the atmosphere, you hold it in the ground, and then you get the added benefit of creating more plant life," Hertz points out.

"Our goal is to make a real impact in the developing world where people don't have electricity, they don't have access to cooling, they don't have communications, and they need water. That is our mission."

Hertz has about a dozen systems in service across California and two others outside of the United States and is set to announce a tie-up with the United Nations this month.