Research into green hydrogen production is advancing at a rapid rate right now, as countries worldwide jockey to establish themselves in what's expected to become a huge global market for clean fuels. Australia's vast renewable energy potential and export-focused economy place it well to compete at high volumes internationally. But as a continent dominated by desert, it's also critically aware of water shortages and the dangers of shipping the lifeblood of its land overseas. Nine liters (2.4 gal) of fresh water per kilogram (2.2 lb) of hydrogen bodes poorly for bulk production.

Creating green hydrogen from seawater is harder than using fresh water; there's corrosion to think about, as well as lots of impurities and micro-organisms. You need coastal locations close to renewable energy – not a problem for a country as large and relatively empty as Australia, but definitely a factor elsewhere. At some scale you need to think about what you're putting back into the ocean after you've finished – whether you're creating dangerous levels of salinity or pumping high concentrations of toxic chlorine back into the marine environment.

But the benefits are pretty huge; not only is your water supply free when you use seawater, but if that hydrogen is burned or run through a fuel cell locally, fresh water is emitted that can filter through the water table and feed the parched land. Desalinated water is one heck of a bonus.