Over the past 25 years, hydrogen fuel cells (HFC) have been the butt of countless jokes in the automotive industry. Many critics see the technology as something long in the works that will never have a future. It’s seen some spotty progress over the past decade, existing alongside compressed natural gas vehicles. But in terms of public perception, HFCs are still on the fringe compared to plug-in hybrids and electric vehicles. In 2016, the Los Angeles Times reported that Toyota expected to sell 3,000 of its $60,000 Mirai sedans by the end of 2017 — and that was an optimistic forecast, mind you. In contrast, Tesla racked up over 232,000 pre-orders for its forthcoming all-electric Model 3 sedan in just 24 hours and Toyota crossed 3.9 million in global sales for the Prius in February.
But while HFC tech struggles in the civilian world thanks to high prices and a dearth of refueling infrastructure, there’s one area where neither of those shortcomings have much bearing: the military. As a way of exploring that application and possibly getting a return on the $2.5 to $3 billion investment it’s made in HFC research, General Motors has designed the Chevy Colorado ZH2, a brawny HFC-powered variant of its off-road-centric Colorado ZR2 midsize pickup. And now, after about two years of design and testing, GM is handing the truck off to the Army.
Aside from its ripped-out-of-Halo looks, the advantages the ZH2 offers over a Jeep or Humvee include near-silent operation, a low heat signature and exportable power. In fact, at GM’s Milford Proving Grounds outside of Detroit where the ZH2 was demoed recently, the truck was barely audible from 60 feet away. The Camaro or Corvette screaming around a distant test track was orders of magnitude louder than the nearby ZH2. Because a hydrogen-fueled engine isn’t using combustion for power, it isn’t going to light up on thermal imaging scans the way a traditional vehicle would, either.
To that point about exportable power, think of the ZH2 as a generator on 30-inch tires. With three tanks of hydrogen onboard (totaling 4.2 kilograms of capacity), the demo ZH2 could power eight homes for 10 hours on 25 to 50 kilowatts. Or four homes for 20 hours. Or a field hospital. Or a forward operating base. Or recharge a battery-powered drone. You get the idea.
On top of that, the only emissions the ZH2 produces are water vapor and deoxygenated air. In an hour, about two gallons of H20 will exit the tailpipe. Run that through a filter and you’ll have something to drink. Oh, and unlike an electric vehicle, the ZH2 doesn’t need to charge overnight; refueling takes around three minutes and extending the range is as simple as adding another hydrogen tank. You could even reclaim the water from the tailpipe and after a few processes, use it to fuel the truck again, albeit with diminishing returns on efficiency. This all makes the ZH2 incredibly attractive to the military.
"Fuel cell technology makes a lot of sense for fleets and installations," said Brian Butrico, chief engineer for the Army’s TARDEC (Tank Automotive Research Division) in an interview earlier this month. "The Army has a lot of fleets and installations."
Today, diesel reigns supreme in the military, but that could change. By Butrico’s estimate, over 50 percent of the time the Army’s vehicles are idling with the engines running. That means more than half of the JP8 jet fuel shipped into the theater of war from the United States is wasted during a given mission.
"It makes a lot of sense here," he said. "We like the aspect of the hydrogen technology that it can be produced in a number of ways. We may be able to source a local resource such as natural gas, regular diesel, wind, solar or nuclear energy and convert that to hydrogen right there, in theater, where we need it."
The ZH2 made its debut last October, but the Army and GM have been exploring fuel cell applications for awhile — first with a with a full-size truck in 2001, and then by including some of Chevy’s "Project Driveway" crossover SUV, the Equinox, into the military pool and installing refueling stations around bases.
2008’s Project Driveway was a 30-month pilot program to glean real-world data from drivers in New York, Washington DC and California (a fuel cell haven) to see how the alternative-fuel SUV performed in the real world. That accumulated data helped pave the way to a partnership between GM and Honda in 2013, and earlier this year, a $1.7 billion joint investment in a fuel cell production plant near Detroit.
Last year, GM engineers were able to shrink the size of an HFC power plant and fit it under a customized Colorado ZR2 hood. From there, GM removed the truck’s back window and rearview mirror, shifted the cab 400mm to make room for those massive tires, reinforced the front and rear body panels with kevlar and carbon fiber, and made "slight" adjustments to the vehicle’s front and rear frame overhangs.
Those giant intakes you see behind the rear doors don’t just look radical, they serve a functional purpose too, feeding the 1,000-pound-per-foot-of-torque propulsion system plenty of air for cooling. The ports are designed in such a way that even when the ZH2 is standing still (say, being used as a generator) they can still suck in enough air to keep the truck from overheating.
Oh, and inside there are the Recaro racing seats and Simpson five-point racing harnesses that keep you strapped into the truck. Essentially, GM took an already absurdly capable off-road vehicle (the diesel ZR2 outputs 369-pound-per-foot of torque) and made it even better. It just took 50 years or research and development to get here.
"You don’t just start these [initiatives], flip a switch and then go," said Charlie Freese, GM’s executive director of fuel cell business. He should know. Freese has dedicated his entire career to diesel, serving as chief engineer of diesel tech at Ford for two years before moving to head up GM’s fuel cell program in 2008. Prior to that he spent 11 years at Detroit Diesel in various roles.
Freese sees an interesting contrast between the two power sources. On one hand, diesel can be incredibly efficient, but it always costs more. Then there are the inherent emissions issues. On the other hand, fuel cells are clean tech, but they’re prohibitively expensive. Freese wouldn’t say anything about price, but the base ZR2 starts at $40,000 before you add the diesel engine (typically a $5,000 option). For comparison’s sake, a Honda Clarity FCV sedan has a $63,000 MSRP. Cost could prove a temporary hurdle, as economies of scale can help bring the price down as more FCVs are produced regardless of who’s buying them.
Now that GM and the Army have done all manner of objective performance testing, it’s time for the ZH2 to undergo a different sort of Project Driveway: a year of hands-on time from soldiers. The truck won’t see live combat; instead it’s going on a tour of military bases around the country to see what it can do in simulated missions, with soldiers ranging from special forces and striker brigades to light infantry. Getting the ZH2 into the hands of soldiers is crucial because so far, Butrico and his engineers have never been downrange.
By this time in 2018, though, the truck will have been exposed to the Marines and Naval Special Warfare units as well. Butrico said it’s important that more than one type of soldier with more than one type of mission evaluate the ZH2.
"The soldiers are going to be who use it at the end of the day, so it’s their feedback that’s most important and most critical to us," Butrico said.
That collective experience from the different branches of the military could be the ultimate test not just for the ZH2, but HFCs in general. The technology is scalable and can be used in many situations, too. For example, there are tests underway with an unmanned aquatic drone powered by compressed hydrogen.
But first, the ZH2 needs to prove its utility before any of that can happen. Assuming this next year of evaluation goes well, Butrico said it could take as long as 15 years for FCVs to be deployed on bases and the battlefield. There have been exceptions to that timeframe when the Army has been particularly interested in something, however.
"It’s not just overnight that I can say, ‘These fuel cells work great; turn on the switch and start producing hydrogen,’" he said.
That doesn’t seem to bother Freese too much, though. When he started his career, diesel technology was facing similar challenges. He remembers a time when the idea of a diesel passenger car was considered laughable, especially here in the US, as no one would want to refuel at a truck stop. Now, plenty of gas stations have at least one diesel pump.
"We’ve overcome that," Freese said.
Hydrogen’s future in consumer vehicles is far from certain. Full EVs seem to be the future, especially once we’ve managed to solve the platform’s ever-present battery capacity problem. So why keep pursuing hydrogen? Because vehicles like the Colorado ZH2 do provide some unique properties — for the right customer.
The military might seem niche, but when you consider how much governments across the globe pay to protect their citizens, it’s a lucrative market. One that automakers might be wise to explore, at least until the kinks have been worked out. Next week, GM has a familiar task ahead of it: waiting and seeing if its multi-billion dollar fuel cell gamble will pay off.