Could pulling water out of thin air help Californians beat the drought?

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Sunday, September 18, 2022
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David Hertz has set up an innovative system that pulls 2,000 liters of water out of the air every day for his Malibu property.

MALIBU, Calif. (KABC) -- California's latest plan to increase the state's water supply focuses on conservation, recycling wastewater, producing new water through desalination and capturing storm water.

But there also are those who want to invest in atmospheric water generation.

What is atmospheric water generation?

It's quite literally pulling water out of thin air.

And David Hertz in Malibu has figured out how to do it quite efficiently.

"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.

Condensation occurs when warm air meets a cool surface. You can see it almost every morning or on items in your refrigerator.

On 99 acres in Malibu, Hertz's WeDew system creates hundreds of gallons of water a day by harnessing that process in a mobile shipping container-turned-water-generator.

Hertz begins by vaporizing 50 pounds of biomass from his property in a gasifier at temperatures near 1,400 degrees. The gases created as a byproduct are used to power a generator which creates electricity for use in his home and to charge batteries.

But for the 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 his soil. Entirely on renewable energy and at a cost of about a 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.

His idea is so successful that he and his wife Laura won the $1.5 million Water Abundance Prize in 2019.

The benefits of the supercharged compost created by adding biochar are obvious in a visit to his gardens.

All of the drinking water on his ranch is created through his process. And by using the shipping containers, the WeDew system can be easily transported to areas with abundant biomass but no drinking water.

"Our goal is to make 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 use across California and two others outside of the United States and is announcing a partnership with the United Nations this month.

Additional research on the safety and effectiveness of atmospheric water generation can be found from the EPA at this link.