Water Extracted from the Air for Disaster Relief
STEVE INSKEEP, host:
As you may have noticed when you buy bottled water, one gallon of it can cost more than gasoline. And in a disaster area or a war zone, jugs of water get even pricier.
Now companies are trying to cash in on the government's interest in finding new ways to supply water during emergencies. Some have developed portable machines that can extract water from the air.
Here's NPR's Nell Boyce.
(Soundbite of dehumidifier)
NELL BOYCE: This is the quiet hum of the dehumidifier in my basement. It has a little bucket that can hold a couple of gallons of water. Now this is machine that looks like a light-blue tractor-trailer. It also extracts water from the air.
Mr. ABE SHER (CEO, Aqua Sciences): In a typical disaster area, our machines will generate approximately 1,200 gallons of water a day.
BOYCE: Abe Sher is the head of Aqua Sciences, a company based in Florida. He's brought his portable water plant to parking lot in Washington, D.C. to show it off to government agencies.
(Soundbite of machinery)
BOYCE: To demonstrate it is not just a bigger version of the thing in my basement, Sher takes a bottle of Coke out of a cooler. After just a moment, the bottle is covered with water droplets. Sher says this is basically the technology inside home dehumidifiers.
Mr. SHER: So they work like this cold Coca-Cola bottle does. They bring the warm air down to the dew point.
BOYCE: But he says this condensation approach consumes a lot of energy and it doesn't work at all in hot, dry environments. So instead, his company relies on chemicals called desiccants.
Mr. SHER: How do we all know desiccants? If you look in your shoebox when you buy a new pair of shoes, you'll see something that looks like a little sugar packet inside.
BOYCE: The material in that packet can suck water out of the air. So can certain salts; that's why table salt clams up when it's humid. In a similar way, Aqua Sciences uses a special highly concentrated salt solution to attract water vapor.
Mr. SHER: And then we extract the water. We treat it and then we deliver it.
BOYCE: The processed water comes pouring out of tap. A trailer like this costs around $300,000. That doesn't include fuels to run a generator. And fuel is a critical issue, because is it hard to deliver water, it's going to be hard to deliver fuel.
Mr. SHER: The amount of fuel used per gallon varies depending on the conditions. Our target is 5 gallons of water per gallon of fuel, or more if possible.
BOYCE: That may not sound like much, but impressed Scott Morris, he's head of FEMA's Office for Long-Term Hurricane Recovery in Florida.
Mr. SCOTT MORRIS (Office for Long-Term Hurricane Recovery, FEMA): Well, I bought two 40-footers and we're going to battle test them and see how they do.
BOYCE: They're in an Orlando parking lot now, ready to roll if a storm is coming. Morris says in a major disaster the government can spend $10-15 per gallon of water.
Mr. MORRIS: What these machines can do is their output is about 20 cents a gallon.
BOYCE: The U.S. Army is also interested. Jay Dusenbury studies water supply at TARDEC, an Army research center near Detroit. He says the Army needs about 16 gallons of water per soldier per day for food, field hospitals, laundry.
Mr. JAY DUSENBURY (Researcher, TARDEC): It's the distribution that then becomes a significant challenge, and this of course can be up to 30 or 40 percent of the trucks that are moving around on the battlefield.
BOYCE: That's why the military is testing two water-from-air machines. They can fit on tanks and travel with the troops. One is made by Aqua Sciences. These machines make a few gallons of water per hour, less in the dessert. But Dusenbury thinks they have potential.
Mr. DUSENBURY: This is an entire shift on how we would do water sustainment on the battlefield. It's a very exciting approach.
BOYCE: Still, the Army probably won't be retiring its water trucks any time soon.
Nell Boyce, NPR News.
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