Hydrogen gas has long been recognised as a potentially valuable tool for tackling climate change. The most abundant element in the universe, it is also a clean-burning gas and – in theory – could be used to power almost anything, from our cars and homes, to planes and ships, to agriculture and heavy industry.

We already produce millions of tons of hydrogen each year for use in the chemicals industry, by extracting it from natural gas - a process which emits CO2. But hydrogen can also be made by splitting water molecules with electricity – and when that electricity is powered by renewables it comes without a carbon price tag.

It is this so-called ‘green hydrogen’ that is currently generating hype around the world as the ‘fuel of the future’ and the missing piece of the decarbonisation puzzle. Across the world, governments are announcing far-reaching hydrogen strategies. Fossil fuel companies, too, are investing big, hoping to cash in on the ‘hydrogen boom’.

But for all the talk of green hydrogen as a miracle fuel, it has a long list of drawbacks too. It is expensive, difficult to store, inefficient and explosive. Previous hype cycles around hydrogen have ended in failure for a combination of these reasons. So while experts agree that hydrogen does have a role to play in decarbonisation, the question is – how big should it be? And are we about to spend hundreds of billions of dollars on a white elephant?

Contributors:

Presenters: Graihagh Jackson and Marnie Chesterton