Paul Fair has clocked about 10,000 kilometres driving TR Group's first hydrogen fuel cell trucks, testing routes and training other drivers.

A partnership to get green hydrogen trucks up and running in New Zealand says there is renewed interest in the technology as diesel prices remain high.

Hydrogen fuel company Hiringa and heavy vehicle leasing business TR Group have faced delays getting their model up and running, but say they are now close to getting a dozen hydrogen fuel cell trucks on the road.

They, and other advocates for sustainable transport, say they offer a helpful alternative to battery electric vehicles for heavy freight.

However, not everyone sees hydrogen as a viable way to decarbonise heavy vehicles, with some critics saying New Zealand should focus on building out battery technology instead.