To avoid taking water from an already strained local supply, a team led by Gang Kevin Li, senior lecturer at the University of Melbourne, Australia, has built a system which extracts water from airborne vapor using a hygroscopic electrolyte, in this case sulfuric acid. The approach then uses solar-generated electricity to split the water into hydrogen and oxygen.
The team proved it could operate at a relative humidity of about 4 percent, well below that of most deserts. On a warm sunny day, the meter-square unit was able to produce 3.7m3 of hydrogen.
“Hydrogen is the ultimate clean energy,” the paper, published in Nature Communications, said. “Despite being the most abundant element in the universe, hydrogen exists on the earth mainly in compounds like water. H2 produced by water electrolysis using renewable energy, namely, green hydrogen, represents the most promising energy carrier of the low-carbon economy. H2 can also be used as a medium of energy storage for intermittent energies such as solar, wind, and tidal.”