With renewable energy sources more widely available, water electrolysis becomes more sustainable, but it can lead to another problem. In many regions, water is already a problem. Using the little available to extract hydrogen might put communities in danger. Thankfully, a new method was developed in Australia, where scientists have created a technique and prototype devices to extract hydrogen from the air.
The new method is still based on hydrolysis. Yet instead of using the water on the ground, it can harness the humidity from the air. The technique allows producing hydrogen with greater than 99% purity, even when the air is as dry as 4% relative humidity. The main advantage is that hydrogen production doesn’t release carbon emissions, and the system works in regions where water is scarce.
The new method comprises a porous foam made from glass soaked in a moisture-wicking electrolyte based on sulfuric acid to absorb water from the air. Electricity from renewable sources like solar or wind can then be used to split the water into oxygen, which is released, and hydrogen, which is collected. The device is estimated to produce 93 liters of hydrogen per square meter in one hour.
The prototype devices are still small, but the team plans to create 1 sq meter and 10 sq meter units in the coming year. One 10 sq meter device would be enough to provide clean gas for a household to cook and heat. Direct Air Electrolysis (DAE), as it was named, has proved to work reliably over a long period. It could also be the first technology to exceed the 20% solar-to-hydrogen (STH) energy efficiency target set by the U.S. Department of Energy.