You have to throw some energy away to make hydrogen – typically around 20-30%, even with the best systems, which use around 52.5 kWh of energy to create a kilogram of hydrogen that can store 39.4 kWh of energy. It's a waste of renewable energy, and it contributes to the high cost of a green fuel option that's really struggling to compete against fossils and batteries in many applications.

That's what makes Australian company Hysata's capillary-fed electrolyzer such an interesting device; at 95% efficiency, it uses just 41.5 kWh of energy to create that kilogram of hydrogen, cutting down operational costs for hydrogen producers – while also cutting down on CAPEX by being cheaper to install and run, to boot. The result: the cheapest green hydrogen going around.