Hydrogen is likely to play a crucial role in our efforts to wean ourselves off fossil fuels, but making it in an environmentally friendly way requires huge amounts of water. Now researchers have developed a new technique that makes hydrogen fuel out of thin air in even the driest climates.
While renewable energy and battery technology are making big strides in decarbonizing large parts of the power and transport sectors, hydrogen could also be an important part of the energy mix.
How eco-friendly hydrogen fuel is depends a lot on how it is produced. Today, the bulk is so-called “Grey hydrogen,” which is made from fossil fuels and results in considerable greenhouse gas emissions.
For hydrogen to contribute to decarbonization, we need to shift to “Green hydrogen” produced by electrolyzers that split water into hydrogen and oxygen using renewable energy.
Now researchers from the University of Melbourne in Australia have developed a new technique that is able to create hydrogen fuel out of moisture absorbed from the air. Access to water would be a major concern if green hydrogen production was to be scaled up significantly.
So they set about finding a way to use this untapped water resource to produce hydrogen. When a current runs through the circuit, the water is split via electrolysis into its constituent oxygen and hydrogen atoms, which can then be collected as gas.
The team showed that the device could run efficiently for 12 consecutive days and produced hydrogen with 99 percent purity. The setup was able to produce an average of 745 litres of hydrogen per square meter per day.
A major issue facing hydrogen fuel is the fact that the infrastructure to distribute it is very different from that used for today’s fossil fuels, often requiring high pressure and even cryogenic storage.
A device like this that allows hydrogen to be made anywhere could help distribute production, which could get around some of these issues.
At the moment the biggest barrier for green hydrogen is cost.
Until electrolyser technology comes down in price and becomes more efficient, hydrogen is unlikely to compete with traditional fuels, whether it’s pulled from thin air or not.