Excerpted from Take the Wheel: A Woman’s Guide to Buying a Car Her Own Damn Self by Kristen Hall-Geisler—new and improved and available November 2017!
To put it really basically, a hydrogen fuel cell vehicle is an electric car that can be refueled at a hydrogen fuel station rather than recharging using a plug. To be even more straightforward and practical about it, you probably can’t buy a hydrogen car anyway. There are three available in 2017: Honda Clarity, Hyundai Tucson Fuel Cell, and Toyota Mirai. The first two are only available in California, which has most of the hydrogen fueling stations; the Mirai is also sold in Hawaii. All told, as of July 2017, there are thirty-seven public hydrogen stations total in the entire country.
Now for the less straightforward tech part. A hydrogen fuel cell takes liquid hydrogen fuel and oxygen from the air and makes water. The process creates electricity, which powers the batteries. The byproducts of this process are water and a bit of lost energy in the form of heat. NASA has used hydrogen fuel for decades, and astronauts drink the resulting water in space. Drinkable water is certainly an improvement over the particulates that come from the tailpipe of a car with a gasoline engine.
Hydrogen is less energy dense than gasoline, though, which means you need to store a lot of it in a big tank in order to go as far between fill-ups as you probably do in your current car. Filling up isn’t exactly the same as it is with a gasoline car, either, though it is similar. Since the hydrogen fuel is a pressurized gas (not gasoline; gas, like not liquid or solid), there’s a system of hoses and seals that need to be connected in order to fill the tank. It only takes about thirty seconds longer, but if you’re freaked out by Windows updates or have a flip phone, this might not be the car for you.
Who Gets the Biggest Bang for This Buck?
Southern Californians are the only people who can really get any practical bang at all from this buck. There just isn’t anywhere else in the country to refuel a hydrogen car. Even if you live in a hotbed of hydrogen fuel stations, there are only a few cars out there to have, and those are usually only leased. You can buy the Toyota Mirai, but the Honda Clarity and Hyundai Tucson are lease-only. With that lease, you usually get free hydrogen fuel, which is a plus. In the case of the Clarity, Honda works closely with customers to improve on the next generation of its fuel-cell vehicle, so if you like being part of the iteration process, that’s another plus. If you want a car that’s already been entirely figured out, hydrogen fuel cells are not going to be your jam.
Is It Really Green?
Hydrogen-powered cars are electric cars that use pressurized hydrogen in a tank rather than electricity from a plug, so there isn’t any combustion byproduct to account for, and the process of turning hydrogen fuel into electricity only results in water.
But that hydrogen isn’t, as you might expect, pulled out of thin air. The hydrogen molecule is rarely found alone in nature, so it has to be processed. Most commonly, as it’s the cheapest and easiest source to deal with, natural gas is the starting point for hydrogen fuel. Natural gas reacts with high-temperature steam or is partially oxidized to produce synthesis gas, which is further reduced to create hydrogen fuel and a little bit of carbon dioxide. The same high-temperature steam process can be used with ethanol to make hydrogen.
Water can be split into hydrogen and oxygen with an electric current, and if that current is generated via wind or solar power, then the result is about as green as fuel comes. Fermenting biomass to create hydrogen is only slightly less green on the scale. Neither of these are as cheap and easy as natural gas reforming. Way down there on the scale is gasification of coal, which also involves high-temperature steam. Then again, you can gasify biomass as well, though it’s really inefficient.
Hydrogen is, for the most part, produced where it’s used, so there isn’t a network of pipelines and tankers delivering hydrogen fuel like there is for gasoline. Also, in order to be put into a tanker, the hydrogen gas (not gasoline, remember; gas) would have to be cryogenically frozen until it was cold enough to become a liquid. And then that truck has to drive on the highway next to you. Oh, the humanity.