Hydrogen is widely touted as a green fuel for everything from cars and planes to heating homes. But all too often it has a dirty secret

By Adam Vaughan

IF HYDROGEN is the future, it has been for quite some time. In his 1875 novel The Mysterious Island, Jules Verne imagined the element replacing coal as a fuel, split out of water to “furnish an inexhaustible source of heat and light”. Similar noises were made in the 1970s oil crisis, when hydrogen was touted as an alternative fuel for cars. And then there was US president George W. Bush in 2003, latching on to a new enthusiasm for hydrogen vehicles during the first wave of real concern about climate change. “We can make a fundamental difference for the future of our children,” he said.

Now hydrogen is back – again. From the US to Australia, and the European Union to China, the past year has seen an almost daily torrent of multibillion-dollar government funding pledges, tests of new technologies from trains and planes to domestic boilers, industry statements and analyses, and championing by leaders such as UK prime minister Boris Johnson. “We’re finding it hard to keep up with,” says Simon Bennett at the International Energy Agency.

“The idea of a hydrogen economy is not new,” says Martin Tengler at analysts Bloomberg New Energy Finance. “Now we’re in another hype cycle. The question is: is it different, or not?”

Tengler is one of many who thinks it is. Meanwhile, another question hangs much heavier than hydrogen in the air: is it really a clean, green fuel to help combat climate change? Or does the significant lobbying of fossil-fuel interests for a hydrogen economy indicate other priorities?

Hydrogen is the lightest element in the universe and the most …