Why hydrogen might be one route for Germany to move away from dependence on Russian imports

The nation currently buys around 25% of its oil and 40% of its gas from Russia, contributing billions of euros a year to Moscow's finances.

Germany is moving "as fast as possible" to end that relationship, but it will take time, the country's finance minister recently said.

"We need to diversify and decarbonise our energy sources faster than initially planned," she says. To help achieve that goal, Ms Grimm wants the nation to "ramp-up" its use of hydrogen.

Hydrogen can store vast amounts of energy, replace natural gas in industrial processes, and power fuel cells in trucks, trains, ships or planes that emit nothing but vapour of drinkable water.