US retail giant Wal-Mart has placed an order with Cellex Power Products for GenDrive fuel cell power units to be used in the firm's lift trucks.

Wal-Mart's order is the largest yet that Cellex's parent company Plug Power has received for the GenDrive technology.

The deal follows 18,000 hours of trials in live working conditions of 12 fuel cell-powered pallet trucks at two Wal-Mart distribution centres in Ohio.

Tom Hoying, Plug Power's Motive Power Division's Vice President of Sales and Customer Operations, said: "This is a significant event for Plug Power and a solid step forward with the widely respected leader in distribution and logistics.

"We believe Wal-Mart's state-of-the-art distribution centres make an excellent proving ground for the commercial application of GenDrive."

Wal-Mart's pallet trucks had previously been powered by lead-acid batteries, with Plug Power claiming that the retrofitting will result in reductions of greenhouse gas and CO2 emissions equivalent to removing around 60 cars from the Ohio's roads.