The "hydrogen economy" has received a lot of hype, but could this explosive gas fill some critical gaps in a future zero-carbon energy system?

Justin Rowlatt looks at Australia's plans to use its huge solar and wind resources to generate hydrogen from seawater. Miranda Taylor of the government-sponsored agency National Energy Resources Australia lists some of the many potential applications for the gas that the country is taking a punt on. But how many of them will actual prove commercially viable?

Clean energy consultant Michael Liebreich says that despite hydrogen's versatility, in most cases it's likely to prove far less efficient than other technologies. But there are a few key exceptions, some of which could be life saving. Plus, chemistry professor Andrea Sella blows up a balloon, zaps some water, and nearly gives Justin a hernia.

Producer: Laurence Knight

(Picture: Hydrogen pipeline with blue sky background; Credit: Getty Images)