First Look: How To Fill A Hydrogen Fuel-Cell Car
By John O'Dell August 25, 2008
By John O'Dell, Senior Editor
If the though of driving around with tanks of hydrogen pressurized to 5,000 pounds per square inch makes you nervous, consider this: Fire fighters routinely enter burning buildings with 4,500 psi air tanks strapped to their backs.
With those words of assurance, GM hydrogen specialist Alex Karos led us out to the fuel-cell Equinox for our first refueling lesson.
----------
GM's Alex Karos, center, explains working of hydrogen fuel nozzle while Edmunds editors Chris Walton (left) and Brian Moody (back to camera) look on.
----------
Yup, I've driven and blogged about the Chevrolet Equniox fuel-cell electric vehicle several times in the past year, even wrote our first-drive review of it for Inside Line. But I'd never actually pumped any of its hydrogen fuel.
Well, General Motors finally has a few Equinoxes (Equinoxii? Equinii?) in its long-term media fleet and has loaned one to the crew at Edmunds for the next week.
So you'll be reading a lot more about it in up coming reviews from staffers for both Edmunds.com and Edmunds Inside Line. We here at Green Car Advisor will provide links to the pieces as they appear so you'll not miss 'em.
Still A Gas
But while you're waiting, we thought we'd try to give you a feel for a fueling process that could someday replace topping off the tank with a gas other than gasoline.
Right now it's a bit more difficult - requiring a greater degree of dexterity than pulling into your local service station for a tank of regular unleaded.
We did, actually, pull into a local service station, a Shell station on the corner of Santa Monica Boulevard and Federal Way in West Los Angeles. Shell recently installed a hydrogen pump there as part of program, backed by the feds, to help get people used to the idea of hydrogen as a fuel for passenger cars.
There are two big islands at the station, one with a bunch of gas pumps, the other with a gas pump and the new one labeled "Shell Hydrogen."
There were 10 of us from Edmunds gathered there the other morning, all aiming to drive the Equinox while we have it and all required to go through the brief fueling lesson so we could fill it up ourselves while out there on the road.
The first thing Karos told us was that hydrogen, while highly flammable, also is incredibly volatile and harder to ignite in the open air than gasoline would be.
The volatility is important because it means that hydrogen, 14.4 times lighter than air, will dissipate rapidly - even when on fire - rather than forming a low-lying pool of fumes, as does gasoline, that can explode or hang around and incinerate everything in sight once ignited.
Tip: If you worry a lot, stay low - maybe kneel down while filling!
The stuff also is odorless, tasteless and colorless non-toxic, non-corrosive and burns with an almost invisible flame, so the filling station is outfitted with hydrogen sensors, heat sensors, sprinklers, 24-hour surveillance cameras, emergency shut-off buttons and a batch of warning lights, all to help ensure nothing untoward happens.
"This may be the safest place in L.A.," Karos quipped.
Talk to Me
There was more, but we'll spare you the pro-hydrogen hype and get right to the good stuff (good, at least, to those who think filling a car with hydrogen after 100+ years of gasoline is interesting).
Retail hydrogen stations are pretty much in their infancy - there are just a handful nationally - and Karos, apologized, some of the equipment is still pretty, ah, rustic.
The pump, for instance, needs to communicate with the vehicle to determine the pressure in the tank, how much fuel is needed and a few other esoteric things only the car and the pump know about.
But instead of a single integrated hose system, or even a wireless communication network, the pump at the Shell station uses both the filler hose and a multi-pin data cable that plugs into a socket hidden behind the Equinox's license plate (top photo).
Twist, Dip, Cha Cha Cha
That means that step two in filling is to hold down the spring-loaded license plate, uncap the data cable receptacle, snap the cable into place with a twist and then tighten the locking collar - all while holding the plate down with your spare fingers, or an elbow, because they didn't think to design it with a latch and if you let go it snaps back up and covers the data port.
Step one is to punch your "certified refueler" PIN number into the touch-screen on the pump housing so that it turns the pump on and unlocks the cover that secures the filler hose and data cable.
After hooking up the data cable - Karos said a wireless system is being tested and should be available soon - step three is to pop open the fuel filler door, check that the little green light is on (it signals that it is okay to proceed with refueling) and connect the filler hose by sliding the nozzle over the fuel tank filler valve and twisting the locking lever into place.
After that, it's a snap: The pump pumps, making a variety of low-pitched hisses and whines as the pressurized hydrogen gas flows into the vehicle; the green light blinks off; the pump stops; and you reach over and press the "finish" icon on the pump's touch screen.
Disconnect and dock the filler cable in its housing, unfasten and replace the data cable, shut the filler door and you are on your way.
Details
The whole thing takes abut 15 minutes if you've got an empty tank - the Equinox takes fuel from two types of pumps, one that delivers fuel at 10,000 psi (or 700 bar), the other -the one we were using - at 5,000 psi or 350 bar.
The difference determines how densely the fuel is stuffed into the tanks - more density means more energy - and, thus, how far the car will go before it is time to refuel.
Fuel pumped at 700 bar is packed more densely into the Equinox's tanks than fuel at 350 bar. The official rating for a 700-bar fillup is 160 miles, while a 350-bar fill may only deliver 80-90 miles.
Most public pumps dispense 350 bar hydrogen and the jury still seems to be out on how quickly 700 bar pumps -- which require more expensive high-pressure hoses and, in the vehicle, more expensive 10,000 psi storage tanks - will be adopted.
An example: The newest fuel-cell vehicle on the road, Honda Motor Co.'s FCX Clarity sedan, uses only 350 bar fuel.
Of course, the four-place Honda is smaller and lighter than the Equinox, and was designed from the ground up to be a fuel-cell vehicle. One result, it can travel 240 miles or so on a single fill, even at the lower pressure.
Looking on the bright side, with the Equinox we'll get a lot more practice using the hydrogen pump.
So if they ever get these things into production, we'll be ready.
LEAVE A COMMENT
Why would any automaker mass produce them????
There is no place to fuel them.
It appears that America would rather screw around with lithium-ion batteries - plug-in hybrids - etc. using an already antiquated overtaxed electric grid losing nearly 12% of the energy just in transmission than build a hydrogen economy.
Just stupid!!!!
And where do you expect the hydrogen to come from?
If it were as simple as that, it would already be here.
Hydrogen is the most abundant element in the universe and America is blessed with oceans of it on three coasts. Recent research both at OSU and MIT has developed catalysts that are inexpensive and in the case of the MIT research can break the bond (H2O) at room temperatures. The only thing stopping the development is a lack of enlightened leadership and the oil company P.R. campaigns designe to keep America sucking at the oil teet.
Does anybody have more info about the MIT Research catalyst that "can break the bond (H2O) at room temperatures" ??
Obviously, there has to be an energy input to the system somewhere. What is it?
ADD A COMMENT