How’s this for irony? As I’m talking to Todd, agreeing to drive a couple miles of save-the-planet future fabulousness, I’m driving my friend’s car, a gross polluter that he couldn’t get to pass its emissions test. As a favor to him, I’m taking it to get re-tested, and it’s wearing an exhaust with four catalytic converters. The exhaust was concocted by another friend of ours to get his cammed-out racing car to pass an emissions test, and the quad cats should be enough to clean the air coming from a Russian coal plant. For the short time that this exhaust is mounted to it, this car is probably producing lower emissions than the FCX Clarity switched off.
But I digress. Just last week, I drove a Chinese-market Volkswagen Passat equipped with a hydrogen fuel cell, so it looks like it’s perfect timing to talk about hydrogen-powered fuel-cell vehicles.
A fuel-cell vehicle primer
First, you have to remember that fuel-cell vehicles are essentially electric cars. However, rather than rely on a battery to store electricity, these cars generate their own electricity on-board. Hydrogen is stored in a high-pressure tank (at 5000 psi or more) and is then run through a fuel cell, which converts the hydrogen into electricity and water. The cars also have a small lithium-ion battery on board to store electricity generated during regenerative braking and to help out under acceleration. It also provides instant power – fuel cells can’t react quickly enough for normal motoring, so the battery acts as buffer.
As electric vehicles, fuel-cell vehicles carry the benefits of electric cars (quiet, smooth operation, and no tailpipe emissions), but with the convenience of fuel-burning cars (quick refueling and long range.)
Volkswagen Passat fuel cell prototype
Because the Volkswagen was a prototype, an engineer accompanied us on our drive. The startup procedure apparently was complicated enough that I wasn’t permitted to do it myself. The engineer sat in the driver’s seat, turned the key on, and the gauges sprung to life. Where the tachometer normally resides is an amp gauge, and its needle moved around a bit as we heard what sounded like a jet fighter (albeit a quiet one) starting up. The whining noise became louder and higher pitched, and just when it sounded like the Passat was about to achieve flight, there was a huge burst of compressed air, which shot water out of the tailpipe a foot behind the car.
At that point, the Chinese engineer, who didn’t speak much English, flicked a switch, got out of the car and indicated that it was my turn to get in. This particular prototype didn’t have regenerative braking, so the brakes would feel like a normal car’s and not like a hybrid’s. Otherwise, he explained, the driving experience should feel quite normal.
Actually, he wasn’t lying – other than the ultra-cool, jet-airplane soundtrack, the Passat drove just as you’d imagine an electric-powered vehicle would. It has no transmission – the motor drives the front wheels directly, so there’s no shifting. The noises you hear coming from the stack aren’t related to speed, they’re from several compressors that are used to feed air into and pull moisture out of the fuel stack – so they’re related to the electrical load, but on kind of a delay cycle. The Passat is also equipped with an 8Ah lithium-ion battery pack, and with a full tank of hydrogen, it has a range of about 145 miles.
I was asked not to give full throttle, but that was a tall order given the quoted 15-second 0-to-60 mph capability. Ultimately, I couldn’t resist, and when I floored it, the ammeter never showed more than 30kW of output from the fuel cell, even though the electric motor is rated at 88kW, or 118 hp. Oh, and the car started flashing its check-engine light at me after a few seconds of full throttle. Whoops.
Honda FCX Clarity
The Honda FCX Clarity isn’t a prototype – it’s sold (or rather, leased) to the public, but its super-low volume makes it just as special as a prototype. You wouldn’t know from its appearance, though, as everything in this car feels as high-quality and well-thought out as any regular production Honda.
The instrument cluster is a marvel of efficiency, cramming loads of information into a small space. At once, you can see speed, fuel range, the charge state of the Lithium-Ion battery, the amount of hydrogen in the tank, and most importantly, the total power the system is producing, broken down between the battery and the fuel stack. Its genius isn’t just how much information is included but how neatly it’s presented. If you don’t care about the specifics, you won’t be distracted from the information you need, like speed and fuel level. The Clarity’s interior is similarly efficient. In fact, it’s enormous – the small fuel cell and compact electric motor allowed Honda to maximize interior space.
The Clarity uses a 100-kW fuel cell matched to a 100kW motor, for a total output of, you guessed it, 100kW, or 134 hp. Its 189 lb-ft of torque are available from a standing start, so it’ll actually squeal its front tires slightly if you mash the pedal off the line – and burning rubber while simultaneously saving the planet? That’s really cool.
What’s also really cool is the stream of water that shoots out the exhaust pipe at full throttle.
Honda says it can cruise up to 240 miles between fill-ups. The fill-ups, by the way, take only a few minutes. And despite the high pressures involved, we’ve been assured that filling the tanks is no more dangerous than filling up a gasoline vehicle. And since hydrogen rises through the air at 40 mph – any spillage dissipates out of harm’s way quickly.
So is this the future of the automobile? Well, insofar as these are electric-powered vehicles, probably. No matter how much I personally love the noise of internal-combustion engines, we need to embrace more efficient technologies. I want a screaming in-line six under my hood for fun, but I think most people don’t care if it’s a hamster under the hood, as long as their car is quick – and as long as they have the (theoretical) ability to drive across the country on a whim.
Hydrogen fuel-cell vehicles’ advantage over battery-powered electric vehicles is their ability to refuel quickly, rather than taking hours to recharge. But there’s also a drawback (in addition to any angst over having 5000 psi of compressed Hindenburg somewhere in the car): hydrogen fuel-cell vehicles are less efficient than pure electrics. While hydrogen is abundant on our planet, it’s usually combined with other compounds, meaning you have to expend energy to get pure hydrogen. You can extract it from natural gas, which kind of defeats the renewable-energy benefit. You can also extract it from water, but that requires electricity.
Once you have hydrogen, you have to compress it to extraordinarily high pressures, which also requires electricity. That electricity could be generated by solar power, but all this solar energy would have been better off just charging a battery in the first place.
That’s not to say that hydrogen fuel-cell vehicles don’t have a place in our future. It’s possible that we could use battery-powered EVs for the daily commute, and hydrogen fuel-cell vehicles for long distance travel.
The good news is that, even as a lover of internal combustion engines, I don’t fear the future after driving the Honda – it’s fast, torquey, and smooth. The VW was just a prototype, but when brought to production standards, it would likely be just as good. And the more fossil fuel saved by the commuting masses means more super unleaded available for those of us who’ll keep our fair-weather fossil-burners for Sunday drives.
For more information on the Hydrogen Road Tour, in which both Volkswagen and Honda are participating, go to http://www.hydrogenroadtour.com