There are currently only around 17,000 hydrogen-powered vehicles on U.S. roads, all of which are in California. Meanwhile, electric vehicles (EVs) number in the millions. While EVs are gaining considerable attention, with major manufacturers aiming for EV dominance by 2030, hydrogen vehicles remain less prominent.
Here’s what you should know about hydrogen cars, how they function, and how likely it is that you might drive one.
You’ve likely heard a lot about electric vehicles lately, along with news about legislation to reduce carbon emissions from vehicles. However, there’s another kind of zero-emission vehicle that emits only water vapor as it travels down the road: the hydrogen fuel-cell vehicle. This technology is related to EVs but has specific differences that make hydrogen cars different and much less common.
To date, almost three million EVs have been sold in the U.S. By contrast, as of mid-2022, 17,000 or fewer hydrogen-powered vehicles can be found on U.S. roads. All of these are located in California, the only state with a network of retail hydrogen fueling stations, making these cars usable.
Hydrogen Cars Currently Available
Since 2015, three hydrogen-powered cars have been available for sale from three car companies: the Honda Clarity Fuel Cell, the Hyundai Nexo SUV, and the Toyota Mirai. However, Honda has discontinued all models of the Clarity. Also, Hyundai has sold only about 1,600 Nexo SUVs in six years.
Toyota, the company with the biggest commitment to hydrogen power as an alternative to battery-electric vehicles, has sold approximately 14,300 Mirai sedans across two generations in the U.S.—though in some periods, they offered significant discounts to increase sales. (Honda does not report sales of its Clarity Fuel Cell model separately from the plug-in-hybrid and battery-electric Clarity versions.)
This year, a new hydrogen vehicle will be released: the Honda CR-V e:FCEV, which is a modification of the popular compact crossover. It features both a hydrogen fuel cell (developed jointly with GM) and a larger battery that can be plugged in. This system provides 29 miles of range, in addition to the 241 miles from the fuel cell. You could think of it as the world’s most complex plug-in hybrid. It will only be available for lease in California, with a projected volume of 300 vehicles per year.
What Is a Hydrogen Car?
A hydrogen fuel-cell vehicle (HFCV) uses the same type of electric motor to turn the wheels as a battery-electric car. However, it’s powered not by a large, heavy battery but by a fuel-cell stack. In this stack, pure hydrogen (H2) passes through a membrane to combine with oxygen (O2) from the air, producing electricity to turn the wheels and releasing only water vapor. This means a fuel-cell vehicle is technically a series hybrid, which is why they’re sometimes classified as fuel-cell hybrid electric vehicles (FCHEV).
To scientists, hydrogen isn’t actually a fuel but an energy carrier. However, HFCV drivers refill their vehicles’ carbon-fiber high-pressure tanks at “hydrogen fueling stations” very similar in concept to traditional gasoline stations, with a five-minute refueling time.
You may hear that hydrogen is the most common element in the universe. While this is true at the atomic level, hydrogen is never found in its pure state. It’s always combined with other elements. Its strong propensity to bind with anything makes it a good energy carrier. Creating pure hydrogen for vehicles requires a considerable amount of energy to “crack” a compound like natural gas (CH4) into pure H2, with CO2 as a byproduct. (Most hydrogen today is derived from fossil fuels.) When run through a fuel cell, the hydrogen immediately gives back that energy, in the form of electricity, as soon as it combines with oxygen. The only exhaust emitted is water vapor (H2O).
Behind the Wheel
In practice, the driver of an HFCV will find the driving experience is almost identical to that of a battery-electric vehicle, though perhaps not one of the faster ones. There’s no transmission, and the car includes regenerative braking to recapture wasted energy as it slows down.
The challenge for automotive engineers is that hydrogen fuel cells perform best at a steady power output. That’s why they are suitable for providing backup power. However, the required power demands in the average car vary by an order of magnitude, from around 15 kilowatts (20 horsepower) — needed to maintain a steady highway speed on a flat road — to perhaps 10 or 20 times that amount during maximum acceleration to 60 mph or higher. The fuel cell in the Toyota Mirai, the best-selling hydrogen car in the U.S., is rated at 90 kW (120 horsepower), but that isn’t enough to rapidly accelerate onto a fast-moving highway. Therefore, Toyota (as do other HFCV makers) includes a high-voltage, low-capacity battery, similar to those used in gasoline-electric hybrid vehicles. This battery provides supplemental power for short periods during intense acceleration and is recharged either from excess fuel-cell output when the car is cruising at a steady speed or via regenerative braking when the car slows.
The three hydrogen cars sold in recent years all have EPA-rated ranges of 300 miles or more. However, like EVs, that range decreases substantially at higher speeds. Acceleration may be better in the new Honda CR-V e:FCEV, given the battery capacity of 17.7 kilowatt-hours—or roughly 10 times the size of the hybrid-only batteries in the other hydrogen vehicles. However, the new Honda hydrogen model is about 500 pounds heavier than a CR-V hybrid, so it’s not a speed demon.
Are Hydrogen Cars Safe?
HFCVs are generally considered as safe as any other car. The high-pressure tanks are designed to survive high-speed crashes without leaking or rupturing. While critics of hydrogen often reference the Hindenburg explosion of 1937, the hydrogen tanks and their hardware would likely survive even if the rest of the car were destroyed in a crash. There have been no injuries or deaths specifically linked to the hydrogen components recorded in the relatively small number of HFCVs sold so far.
Pros and Cons of Hydrogen Fuel-Cell Vehicles
HFCVs share some positive features with battery-electric cars: they’re smooth, quiet, and peaceful to drive, and they emit no carbon dioxide or other harmful exhaust—only water vapor. They also avoid the charging time problem that EVs have; refueling ideally takes only about five minutes for another 300- to 400-mile driving period.
However, there are also disadvantages, the biggest of which involves the availability of hydrogen fuel. While plans from a decade ago aimed for California to have 100 hydrogen stations by now, the actual number is less than 60. And that number isn’t growing much. Shell recently closed its seven hydrogen stations in California.
Most problematic, not all stations are online and available at any given time. You can view the total number of “H70” green dots in the real-time Station Status report maintained by the California Fuel Cell Partnership to see how many are live at any given moment. Many hydrogen drivers rely on this app to plan their fueling stops before they leave.
Hydrogen Fueling Stations
Fueling a hydrogen car becomes easier with practice, but aligning the heavy nozzle and sealing it correctly so the car and pump can communicate electronically can take some getting used to. Today’s stations can often fuel only two to five vehicles before going offline for up to half an hour to repressurize. As HFCV drivers in the San Francisco Bay Area discovered in June 2019, the infrastructure for supplying hydrogen to retail outlets is very thin. An explosion disrupted the supply to nine of the area’s 11 hydrogen stations, requiring diesel trucks to transport compressed hydrogen tanks hundreds of miles from Southern California overnight. Drivers depending on their hydrogen vehicles struggled to fuel up, and ended up having to set alarms for the early hours, hoping to reach a fueling station in time to get some of the limited hydrogen fuel. Toyota ended up refunding several months of lease payments to Mirai drivers throughout the state who couldn’t reliably use their cars.
The major contrast, and biggest disadvantage, of hydrogen cars compared to EVs, is that they’re similar to gasoline cars, as they can’t be “refueled” or recharged at home overnight. But unlike gasoline cars, for which there’s a well-developed set of more than 100,000 fuel stations across the U.S., hydrogen drivers are completely dependent on both a reliable supply of the gas itself and an available—and properly operating—high-pressure fueling station.
Cost of Hydrogen Fuel
As hydrogen fuel is a specialized commodity for the general public, the limited network of retail stations charges high prices. In late 2022, according to information from the California Hydrogen Business Council from a now-deleted page on their website, “A kilogram of hydrogen costs between $10 and $17 at California hydrogen stations, which is equivalent to about $5 to $8.50 per gallon of gasoline” to cover the same distance. (A Toyota Mirai hydrogen car holds about five gallons of hydrogen.) Charging an EV overnight usually equates to the cost of gasoline at just $1 to $2 a gallon. To offset this disadvantage, Honda, Hyundai, and Toyota have offered lessees and buyers free hydrogen fuel for limited periods.
Each manufacturer has a slightly different offer: a Toyota Mirai includes up to $15,000 of complimentary hydrogen, while a Hyundai Nexo provides the same value over a three-year lease or up to six years of ownership. After those offers expire, the driver is responsible for the cost. In 2023, True Zero, California’s largest hydrogen supplier, raised its price to $36/kg—from $13.14 less than three years prior. A full 5-kg refill in a Mirai could cost up to $180.
Servicing a Hydrogen Car
Like electric cars, hydrogen vehicles require that dealership service centers take special precautions. HFCVs have the same high-voltage battery packs as a hybrid, plug-in hybrid, or electric car, but they also have one or more armored, carbon-fiber tanks to hold pure hydrogen under extreme pressure: 10,000 pounds per square inch (psi), or 700 bar in metric. Routine service for a hydrogen car that doesn’t involve the hydrogen tanks, the fuel-cell stack, or the connecting plumbing is just like servicing any other vehicle. But if any of those components need handling, the state of California has a set of rules to ensure any escaping hydrogen doesn’t risk an explosion.
These rules include the partial draining of hydrogen tanks in specific outdoor areas away from buildings. Then, the rest of the system is purged of any remaining hydrogen by flushing components with various gases, a process that takes between 30 and 180 minutes.
The Future of Hydrogen Cars
If you’re in California and want a zero-emission vehicle powered by an electric motor, a hydrogen vehicle is one option. However, at the moment, it’s a considerable risk. Building a brand-new fueling network from scratch has proven far more problematic—both expensive and unreliable—than automakers initially projected, and the fuel is pricier for drivers than gasoline or electricity. Without available hydrogen fuel, reliably delivered at 10,000 psi, an HFCV is just an expensive doorstop. If we had to guess, the passenger car future is more likely to be electric.
John Voelcker
John Voelcker edited Green Car Reports for nine years, publishing over 12,000 articles on hybrids, electric cars, other low- and zero-emission vehicles, and the energy ecosystem surrounding them. He is now a reporter and analyst covering advanced auto technologies and energy policy. His work has appeared in publications such as Wired, Popular Science, Tech Review, IEEE Spectrum, and NPR’s “All Things Considered.” He splits his time mostly between the Catskill Mountains and New York City and still hopes to become an international man of mystery one day.
