The battle over cars running on alternative fuel shifts up a gear this year. A record number of new models powered by electric batteries are due to be released in the coming months as manufacturers place their bets on greener solutions to petrol engines.

But two of the biggest carmakers, Toyota and Hyundai, are still driven by the belief that hydrogen will become a key source of clean energy for the future. That obsession with hydrogen fuel cell vehicles looks more justified now than it has sometimes appeared in the past.

Extreme volatility in natural gas prices in recent months and the need to find alternatives for Russian resources have renewed interest in the potential for hydrogen fuel. Large vehicles, such as trucks, need an alternative to battery electric power. The distances they travel mean electric alternatives require heavy batteries.