Back in October 2016, the XPrize foundation turned its attention to the issue of water security, pointing to the growing strain placed on water resources by rapid population growth and climate change. Its US$1.75 million Water Abundance Prize aims to inspire ideas that can draw water from the atmosphere, and it has just announced its five finalists.

The criteria for the Water Abundance Prize tasks competing teams with developing technologies that can harvest 2,000 liters (528 gal) of water from the atmosphere each day, using only renewable energy at a cost of no more than two cents per liter (0.26 gal).

The competition drew submissions from 98 teams hailing from 25 countries, and has now been whittled down to five entrants based on their technical documents, early test results and video evidence of a working prototype. They now have five months to continue building their devices for the final round of testing.

Hydro Harvest Operation is a team from Newcastle, Australia which is looking to use its expertise in developing emission-free engines that generate electricity from geothermal and industrial waste to build a simple, cost-effective device for harvesting water.

Hawaii's Team JMCC WING is spun out of James McCanney's company JMCC Water Filters, which offers atmospheric water generators as part of its range. These require large energy resources that aren't always available in impoverished regions, so McCanney is adapting his technology to suit the criteria of the XPrize, working on a more efficient device that combines a wind-powered generator with an atmospheric water harvester.

A team called Skydra from Chicago is keeping its cards pretty close to its chest, but is looking to build a system that will incorporate both natural and engineered systems. Team Uravi from India is also not giving much away, but is building a completely off-grid water harvester that will make use of advanced material sciences and solar thermal energy.

The Veragon & ThinAir Partnership from London is looking to not just harvest regular old water, but use its device to produce high quality mineral water. Its Air-to-Water water generator incorporates a new surface material inspired by nature and developed at Imperial College London, claimed to better encourage water nucleation (the formation of droplets). How that water is then mineralized is not yet clear.

"Water is our lifeblood," says Zenia Tata, vice president of Global Impact Strategy at XPRIZE. "With alarming water shortages impacting livelihood around the world, we are in dire need of decentralized and democratized water breakthroughs now more than ever. The promising prototypes presented by these five finalist teams bring us one step closer towards finding a cost-effective solution for extracting water from thin air and offering on-demand access to water, anytime and anywhere."

A $250,000 milestone prize will be split between the five finalists, with the $1.5 million grand prize to be awarded in August.

Source: XPrize