Like the chemical element itself, the idea of using hydrogen energy has floated around for a long time. The first hydrogen fuel cell appeared 182 years ago. Yet using hydrogen as a source of energy has never taken off. In its gaseous form it does not exist in abundance. It must be split away from water or hydrocarbons. Moreover, producing it sustainably is costly. That may all change in the coming decade.

Hydrogen could replace natural gas over time. It contains enough energy in its molecules to do so. That means it could also help to elbow out coal and crude oil from energy consumption. As Marco Alverà points out in The Hydrogen Revolution, transport infrastructure already exists. He should know. Alverà runs Italy’s natural gas pipeline company Snam. Converting regional gas pipelines to carry hydrogen drastically reduces its transport cost.

The idea of using hydrogen fuel cells for transportation receives heavy attention. But hydrogen use in households and heavy industry could make more of a difference — if costs fall. Consider steelmaking, responsible for 9 per cent of carbon emissions in 2019. Steel requires coking coal to transform iron ore into pig iron, an early stage of steel. Switching from this method to hydrogen requires the latter’s cost to drop from about $3 per kilogramme of hydrogen gas to at least $2. Otherwise the added cost makes the steel uneconomic.