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These 3 New Devices Can Suck Water From The Air To Solve Our Droughts

Where rain is scarce, new technologies are able to harvest moisture directly from the atmosphere–even in dry environments.

Benjamin Blumenthal, one of the co-founders of SunToWater, is making a new appliance that seems a little bit like magic: Even in the middle of a desert, the device can pull drinking water out of thin air.

“We’re using air, sunlight, and salt, and we’re making water,” he says.

The company won first place in Singularity University’s 2015 Impact Challenge, which is bringing entrepreneurs to its Silicon Valley lab to work on technologies that can help solve the growing global problem of drought.

By pushing air over salt, the SunToWater device–that’s it in the bottom left of the house in the picture above–can suck drops of water out of the air and then pull the water out of the salt when it needs to be used. It’s designed to work even in the driest air in the planet.

“Cracked-earth Africa, where nothing can grow, is 18% relative humidity,” says Blumenthal. “Our engineers created an artificial environment with 14% relative humidity, and we were still able to produce water. Wherever people can live, it can provide water.”

In a place like a remote part of sub-Saharan Africa, a group of the devices, which can each harvest 20-40 gallons of water in a day, could serve as the only water source. The same could be true for homes in California.

“You could certainly put a network of these units into a village in Africa and provide all the water that they require,” he says. “In California, if people want to take their house off of the water grid, the same way that they took their house off of the power grid using solar panels, they could put one or two units in their home and they’d be water independent.”

Even if the technology was used at a large scale, the startup says it wouldn’t have an effect on the weather. “The water cycle is truly enormous,” says Blumenthal. “The USGS says there’s 12.9 trillion tons of water in what is essentially an ocean above our heads. If you were to prick your finger and drop a little bit of blood into the ocean at the beach, have you bloodied the ocean? Technically, yes, but statistically, not at all. That’s the same principle here.”

The catch: The technology is right now even more expensive than desalination. The company estimates that it would cost about 3.5 cents to make a gallon, including energy costs, in a place like Los Angeles. But desalination only makes sense along the coast, where ocean water is plentiful.

“If you want to move desalinated water inland, you either need to build a billion-dollar pipe infrastructure, or you need to pipe water, which leaves you with the uncomfortable problem of burning gasoline to move a small amount of water,” he says. Taking water from air, on the other hand, can happen anywhere.

SunToWater, which is a spinoff from the electronics company Flextronics, isn’t the only startup working on this type of device. Another finalist in the Singularity University contest, Permalution, is focused on harvesting water from fog–something that California still has an abundance of despite the drought.

“We’re mimicking the spiderweb in the morning, where the dew droplets would appear in the surface of the fiber, but on a big scale,” says Tatiana Estevez Carlucci, co-founder of Permalution. Using 65-by-29-foot screens, the company can catch fog and drip it down into a storage tank.

The company estimates that about 21% of the West Coast is exposed to coastal fog and could start collecting it. It’s a process that used to happen more naturally–redwoods and some other trees also collect fog and drip it down to their roots, but as trees have been cut down, some of that has been lost.

“There’s only 3% of that vegetation left in the state,” says Carlucci. “It’s necessary that we bring this source of water back.”

Permalution is working with regulators in San Francisco and Marin County to get approval for fog harvesting and hopes to start providing a new water source for irrigation and fighting wildfires.

A third finalist in the Singularity University contest, the Philippines-based AWE, produces both water and energy from air simultaneously.

Producing water was actually an unintended benefit: The company started by trying to find a new way to produce wind power. While most wind power requires high wind speeds–around 20 miles an hour–the new machine works with winds as low as two miles an hour, when it’s barely possible to feel a breeze. The device compresses air to store it, but as the engineers designed the device, they realized it only worked with dry air. They had to squeeze humidity out of the air–and that meant they suddenly had a new source of water.

“We said, ok, let’s rethink the whole thing,” says Richard Joye from AWE. “It isn’t just a wind-driven energy device, but a water-extracting device that doesn’t require energy to work. It produces water and produces energy, solving two problems at once.”

Each unit can produce between three and 120 million gallons of water in a year. “The small units are more for natural disaster or emergency response, or remote communities,” says Joye. “Here in the Philippines, we’re working on an island where they have no power and they have no fresh water.” He says the large-scale devices could compete with large wind or solar farms.

As a startup, Joye thinks AWE is in a better position to take on global environmental challenges than more established companies, even those already working in something like renewable energy. “If you look at water and wind, even to some extent solar, there haven’t been real breakthroughs in the last 40 years. … If you look at wind, the turbines are much the same as they were in the 1980s,” he says.

“We’re nimble, flexible, small, but we’re starting to attract money from VCs,” he says. “I think we live in interesting times because now there’s high pressure to serve the environment, climate change, water problems, and small companies can really address these problems fast.”

He thinks there’s room for several new startups in the space. “We need a portfolio of solutions,” he says. “I don’t think one technology can address the whole problem, at least not in the short term.”

About the author

Adele Peters is a staff writer at Co.Exist who focuses on sustainable design. Previously, she worked with GOOD, BioLite, and the Sustainable Products and Solutions program at UC Berkeley.



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