General Motors said Thursday it will build a hydrogen fuel cell version of its Colorado pickup for the US Army, giving soldiers a quiet and fuel-efficient reconnaissance vehicle for tough combat environments.

GM said the modified Colorado, a mid-sized pickup, would put its fuel cell technology to test under "the extremes of daily military use."

It signed a multi-year contract at the end of September with the army's Tank Automotive Research, Development and Engineering Center (Tardec) to develop and test the truck.

Tardec operates a fuel cell research facility close to GM's own fuel cell center near Detroit, Michigan.

"The potential capabilities hydrogen fuel cell vehicles can bring to the warfighter are extraordinary, and our engineers and scientists are excited about the opportunity to exercise the limits of this demonstrator," said Tardec Director Paul Rogers.

The advantages for soldiers in the field of fuel cell-powered electric engines are more than just the cheapness and unlimited supply of the fuel involved, hydrogen.

The engines run extremely quietly, and are also available to generate electricity for other field needs.

Moreover, the vehicles can offer a high amount of torque at low gear levels, which is important in rugged terrain and in carrying or pulling heavy cargos.

"FCVs are very quiet vehicles, on which scouts, special operators and other specialties place a premium," Rogers said.

"What's more, fuel cells generate water as a by-product, something extremely valuable in austere environments."

"It's environmentally friendly," GM spokesman Dean Flores told AFP.

"The only emission is water. Beyond that, fuel cell vehicles can be used essentially as a portable generator. It can power hospitals" for example, he said.

GM has already been testing fuel cell engines in more than 119 Chevrolet Equinox sport utility vehicles for eight years, some of them used by the military.

In July, the company said they had, as a group, run over 3 million miles (5 million km) through every kind of weather, "proving that fuel cells can meet the demands of real-world drivers."

The US automaker has also been working since 2013 with Japan's Honda to co-develop the next generation of fuel cell and hydrogen storage systems, with a target of 2020 for commercializing the technology.

The challenge to popularizing the technology includes a still-high vehicle cost, and the lack of infrastructure for distributing and replenishing the hydrogen fuel.