The $3m (£1.8m) project is part-funded by the U.S. Energy Department’s recently-announced $7m (£4.25m) investment in hydrogen fuel cell technology and infrastructure, and FedEx Express will work with Smith Electric Vehicles – the manufacturer of most of its electric delivery vans – and Plug Power.

Fitting a 10kW Plug Power hydrogen fuel cell system to the Smith Electric Newton vans doubles the pure-electric model’s 80-mile range, allowing the vans to be feasible for nearly delivery routes, according to FedEx Express. It also means the vans can be used for a wider range of applications.

Hydrogen fuel cells use a reaction between hydrogen and oxygen to generate the electricity used to drive the vans’ electric motor and recharge its lithium ion battery. Refuelling takes minutes and the only by-product is water vapour.

Plug Power claims a 50% increase in fleet efficiency and a 35-40% decrease in fuel expenses compared to an equivalent diesel vehicle, as a result of using its hydrogen fuel cell technology.

Andy Marsh, Plug Power CEO, said: ‘Early customer experiences with electric delivery vehicles have been overwhelmingly positive. But only 1% of these vehicles are electric today; we think that this range extender provides the added distance and quick refueling capabilities needed to really grow this market.’