Milford — Seeing it in person, it’s hard to imagine the Chevrolet Colorado ZH2 — a fuel-cell vehicle designed for the U.S. Army — could do anything but roar when it’s running.

And then you realize, it’s already running.

General Motors Co. engineers designed the truck, which stands 61/2 feet tall and 7 feet wide, and has 37-inch tires. On Monday, they turned over the keys to officials with the U.S. Army Tank Automotive Research Development Center (TARDEC) in Warren.

Charles Freese, executive director of GM’s global fuel-cell business, said the project kicked off a year ago when the carmaker and military officials compared notes.

“GM and the TARDEC Team decided that some of the things we were working on could be very interesting for military applications as well,” he said. “And GM has been exploring the merger of the Chevrolet Colorado ZR2 technology … and the technology of the fuel cell.”

The technology under the massive truck’s hood represents a major opportunity for electric vehicles and possibly, for the military.

Fuel-cell vehicles are powered by hydrogen gas that, when mixed with oxygen, generates power for an electric motor. While they have yet to find widespread use, the vehicles produce no harmful emissions — only water — and are seen as having great potential.

For military purposes, it offers other benefits. The ZH2’s electric powertrain operates with less noise than traditional internal combustion engines, and also produces less heat. In situations where stealth and quiet are required, this version of the Colorado provides a distinct advantage.

“When you hear it out there, you’ll hear the tires going across the road, but you won’t hear the engine running,” said Paul Rogers, TARDEC’s director. “So if you’re a special operator, if you’re a recon soldier and you’re trying to be stealthy, you can sit in this vehicle and you can observe the enemy. And you’re not running a generator or you’re not running a vehicle powerplant that’s making a lot of noise and giving away you’re position.”

In addition, the ZH2’s electric drive system also produces a high torque level, Rogers, said, that “has many synergies with an off-road vehicle,” whether for for climbing hills or slogging through mud.

GM officials first unveiled the ZH2 in October.

Gov. Rick Snyder, on-hand for Monday’s ceremony, said the Colorado project fits squarely within the three research areas driving the latest technologies in the automotive industry.

“The one we talk about all the time are the intelligent vehicles — autonomous vehicles,” he said. “But people forget there are really two or three huge tracts going on. There is also the issue of lightweight materials, and then propulsion systems. And they will revolutionize things.”

U.S. Sen. Gary Peters said locally developed technologies boosting the electric vehicle will only help the region in the autonomous race.

“Probably the ideal powerplant for these new kinds of technologies will be electric,” he said. “Whatever may happen to the price of oil and other issues … if you just look at it from a technological standpoint, with self-driving systems, autonomous vehicles are going to need electric powerplants for the engineers to fully realize their dreams of where they want to go.”

The Colorado ZH2 vehicles will be evaluated for full-time use at a series of military bases around the country in the next 12 months.

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