Can stripping the air of its moisture quench the world’s thirst?

Can stripping the air of its moisture quench the world’s thirst?

Water-from-air technologies use science to squeeze water from the atmosphere

by Bethany Halford


we live in a thirsty world. Each person on Earth needs about 50 L of water each day to meet basic needs, including water for drinking, food preparation, sanitation, and personal hygiene, according to the World Health Organization. Despite the planet’s rich water resources, scientists estimate that 4 billion people—more than half the world’s population—don’t have enough water for at least one month each year, and 500 million of them don’t have enough throughout the entire year. Factor in climate change and a global population expected to reach 10 billion by 2050, and it becomes clear the world is only going to get thirstier.

The atmosphere contains as much as 1.29 x 1016 L of water, in the form of clouds, fog, and water vapor.

scientists agree there won’t be a single technology that’s best for every locale. In foggy areas, the answer may be putting up systems that can coax water droplets suspended in the air to coalesce. In humid climates, where the air is thick with water vapor but the vapor hasn’t nucleated into droplets, devices that can condense and collect it might be best.

specialized machines that can sop what little moisture that’s around will need to be developed.

water from air may be the only solution for providing enough drinking water for everybody.

Roland V. Wahlgren, principal, Atmoswater Research



Currently, Bourgon says, the technology’s cost comes out to about 6 cents per liter of water. That’s about six times the cost of a liter of desalinated water, but it’s far less than bottled water, which ranges from 21 cents per liter in Turkey to $1.25 per liter in Denmark.

Drinkable Air, for example, has been in the business for eight years. The company’s products range from small units designed for in-home use to a trailer-sized setup that could provide enough water for a large hotel, about 150,000 L per day. Like most commercial water-from-air devices, it collects water vapor in air using a cooling system.

“It’s a dehumidifier on steroids,” Michael Bourgon, Drinkable Air’s international business development director.

  1. The machine pulls in air through an electrostatic filter,
  2. which removes dust and other particles.
  3. Then the air passes over the cold surface of a condenser,
  4. which is coated with a lubricant that’s safe to consume.
  5. Vapor collects on the condenser’s surface as liquid water,
  6. which drops into a collection tank.
  7. Drinkable Air’s patented ozone purification system cleans the water further. Before it’s ready for drinking,
  8. the water travels through a carbon filter and a mineral cartridge,
  9. which adds calcium, magnesium, and sulfates to make the water more alkaline and improve its taste.

Roland V. Wahlgren it comes down to cost,

“Even if you had a dirty, polluted source of liquid water, it would be cheaper to clean that up with conventional water treatment methods than to use a water-from-air machine to provide the same volume of water per day” when you factor in equipment and energy costs, he explains.

“Water from air may be the only solution for providing enough drinking water for everybody,” he says.

Even so, Wahlgren thinks the move to water harvesting might be too slow for these cities. “Perhaps some water-from-air companies will fail because they can’t stay in business long enough until the demand makes those businesses viable,” 

Jonas Wamstad, CEO of the water-harvesting company Drupps, is hoping his company, which spun off from the humidity-control company Airwatergreen in 2017, Drupps’s technology doesn’t use cooling but instead relies on a liquid desiccant to pull moisture from the air,

  1. Sitting in one module of the device that’s roughly the size of a shipping container,
  2. soaks up moisture from the air. 
  3. moves into a second module,
  4. where water is boiled off, cooled, and collected.
  5. Dried of its water,
  6. returns to the first module to repeat the process.

The technology, works most places on Earth, except for the driest desert,

costs about 2 cents per liter of water.

energy-intensive system. But it can be powered with thermal energy—burning garbage,

Looking to bring down the cost of water-from-air systems, the Water Abundance XPrize is offering a $1.75 million purse to anyone who can come up with an atmospheric water-harvesting device that can deliver 2,000 L of water per day at a cost of 2 cents per liter using only renewable energy.

[   ]opened in October 2016, and by May of 2017, 98 teams from 25 countries had entered. In March, XPrize announced five finalists, who are the winners

devices that pull water from the air show promise and with continued innovation could make the thirstiest parts of the world a little less parched.