Pulling into a gasoline station is so commonplace that we never give any attention to how a gasoline station works. Hydrogen filling stations work very much like common gasoline stations, but with some key differences.
Drive into a hydrogen filling station, and you’ll be forgiven for noting just how normal it looks. Fuel pump. Touchscreen. Nozzle. Overhead lights under a canopy. But after realizing it is a hydrogen station, you may wonder how a hydrogen filling station works. Well, wonder no more.
How Hydrogen is Transported to Filling Stations
Hydrogen usually arrives at a filling station the same way gasoline does: on a truck. Also like gasoline, hydrogen can also be transported via pipes, such as the hundreds of miles of pipeline that already exist in the United States. But unlike gasoline, it can also be generated on-site by separating the element from water or natural gas.
If hydrogen arrives in liquid form, it must first be converted into a gas before it can be used. Here, it passes through vaporizer towers that heat the liquid until it turns into gas.
Hydrogen Compression for Vehicles
Before hydrogen goes into your car, it must be compressed to high pressure. Hydrogen is dispensed as a pressurized gas. There are two standards for hydrogen compression: half-pressure H35 and full-pressure H70. The numbers H70 and H35 refer to the pressure at which hydrogen is dispensed. The H70 designation indicates a dispensing pressure of 70 Megapascals (MPa) or approximately up to 10,000 pounds per square inch (psi). Higher pressure translates into higher range: On a modern fuel-cell vehicle, a full fill at H70 equals 312 miles of range, which is on par with gasoline-powered vehicles.
Now all hydrogen passenger cars operate at H70 and new stations may not offer H35 fueling. Although H35 is still being used for commercial vehicles.
Hydrogen Storage and Safety
The hydrogen sits in storage tanks, just like gasoline. The main difference, however, is that hydrogen tanks are above ground, while gasoline is stored below ground, to the tune of thousands of gallons. Gasoline leaks and fire are far more devastating to a vehicle than a hydrogen leak. Any leak in a storage tank means that hydrogen, which is lighter than air, simply vents away before it has the chance to combust.
To prevent expansion and to maintain energy density while being pumped in at high pressures, hydrogen must be cooled through a heat exchanger before it passes through a pump. The cooling prevents the vehicle’s onboarding tanks from overheating, speeding up fueling.
So, there you have it. While very advanced, a hydrogen filling station is really not so complicated. And fueling a hydrogen fuel cell car is as easy as pumping gasoline. Click here to learn more about hydrogen fuel cell vehicles and how to fill them.
Find a Hydrogen Fueling Station
Visit the Alternative Fuels Data Center to find hydrogen fueling stations in the United States and Canada.
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