Germany has deployed 14 hydrogen-powered trains in its Lower Saxony region, replacing diesel locomotives on a sixty-mile network. Hydrogen is a zero-emissions fuel and can kind of piggyback on existing diesel refueling infrastructure. It seems like the perfect replacement for gas cars, too, because we wouldn’t have to change the entire charging paradigm like we will for electric vehicles. But the reality, as you may have guessed, is more complicated. “On the face of it, filling up with hydrogen looks like filling up with gas. You pump it in, and off you go,” Arnas Vasiliauskas, founder of CarVertical, told Lifewire via email. “And hydrogen-powered cars are also very pleasant to use. They are lightweight and have fewer moving components, so there’s less vibration, making existing hydrogen vehicles remarkably quiet and smooth to drive.”
It’s a Gas
Right away, things get difficult. Gas, despite its name, is a liquid at ambient temperatures, whereas hydrogen has to be kept under immense pressure to keep it in a liquid state. And hydrogen is even trickier than liquefied petroleum gas (LPG). “Even though it takes five minutes [to fill up], charging stations for hydrogen are extremely expensive because they have to work at extremely high pressure,” car enthusiast Petar Dzaja told Lifewire via email. “For instance, the pressure of gas in a typical LPG vehicle is around 10 bar [145psi], while in hydrogen vehicles, it’s 700 bar [10,000 psi].” This also means that a hydrogen pump costs way more than a simple gas pump, and that’s before we get to the guy who insists on smoking while he gasses up his vehicle. “Hydrogen can’t be distributed through existing infrastructure like underground natural gas distribution pipes. A dedicated distribution system would be required, at great cost,” Ron Cogan of the Green Car Journal told Lifewire via email. “That’s not to say that it can’t, or shouldn’t, be done…just that it will take a significant financial commitment. In the meantime, hydrogen is transported in large trucks, not unlike gasoline.” That’s why there are relatively few hydrogen-powered cars available. There’s nowhere to fill them up, and while it looks like one could convert—or add to—existing gas stations, the cost is so high that nobody will do it before there are more hydrogen cars on the road.
Not So Clean
The other downside of hydrogen is it’s not particularly green. When you burn it with oxygen, it turns into water (although it can also produce oxides of nitrogen. That part is fine and one of hydrogen’s major attractions. The problem is producing it. “Most hydrogen used today is extracted from methane (a fossil fuel), and this hydrogen is not considered a ‘green’ fuel, even though hydrogen itself is an amazingly clean fuel as it is being used. ‘Green’ hydrogen can be created by electrolyzing water to split it into hydrogen and oxygen, and this is being seriously explored. The challenge is that the process requires a lot of energy (electricity) to do this,” says Cogan. Ideally, that energy would come from renewable sources, but once you’re generating huge amounts of renewable energy, why not just send that down existing wires to recharge electric cars?
All Aboard
Trains, though, may be another proposition entirely. Much of Europe’s railway network is electrified, but if you’re starting from scratch with a diesel-only network, hydrogen can make sense. You have way fewer fueling points to refit, and as the refueling is done by professionals, it should be safer. “Running a train on hydrogen is also straightforward but requires much less investment in infrastructure than overhead wires. You store enough hydrogen on the train for any given route,” says Cogan. Replacing fossil fuels is hard because they’re so entwined in everything we do. We need bigger changes than just replacing one form of fuel with another. One of our biggest problems is cars themselves. We’re too used to them, and in some areas, cities are designed around them. Instead of building out networks of hydrogen stations or strip-mining the world to build enough batteries, we should look at ditching cars. Cities don’t need them, and converting public transit to electric is totally possible—trams and underground metros already do it. The reality is this: it’s time to think about new ways to clean things up.
