There are two approaches to producing hydrogen: blue hydrogen (made by splitting natural gas into hydrogen and carbon dioxide) and green hydrogen (produced by splitting water via electrolysis into hydrogen and oxygen).

Green hydrogen requires a large energy input from a renewable source to be considered carbon neutral, but blue hydrogen cannot be described as a zero-emission fuel source unless coupled with significant carbon-capture efforts. One study showed that hydrogen derived from fossil fuels can actually be more carbon intensive than using gas.

Some 95 per cent of today’s commercially produced product is blue hydrogen made by steam-methane reforming using natural gas feedstock.

The number of announced projects for low-emissions hydrogen continues to expand rapidly while more than 40 countries worldwide have set out national hydrogen strategies to date.

But installed capacity and volumes remain low as developers wait for government support before...