Everybody pretty much knows what a gallon of something looks like. Think about a gallon of milk in your fridge. And every driver—for better or worse—knows how much a gallon of gasoline costs, and how far it will take you down the road. But ask somebody to picture a kilogram of gaseous hydrogen, and you’ll get a blank stare.
A couple rules of thumb will help us better understand the cost of H2 vehicle fuel. Here’s the first one:
A kilogram, or 2.2 pounds, of hydrogen contains nearly the same amount of energy as a gallon of gasoline
When using the industry norm of 10,000 psi storage, it will usually take about four or five kilograms of gaseous hydrogen to fill up your tank. The reason that about five kg will yield nearly 300 miles per tank is the extraordinary efficiency of a hydrogen fuel cell vehicle. So, a car like, say, the Toyota Mirai—if powered by gasoline—would get perhaps 30 miles on a gallon of petrol. However, the hydrogen fuel-cell Mirai is about twice as efficient as a gas car, so those five kilograms of hydrogen add up to nearly 300 miles of driving range.
Some analysts peg the hydrogen fuel efficiency advantage at closer to 2.5x—but it depends on car size, aerodynamics, driving style, acceleration mapping and other factors to make a more precise calculation. Again, we’re trying to use general rules to gain a better understanding of the relative cost of H2 for a car.
When I drove a Toyota Highlander FCH-adv, a hydrogen-powered SUV, for six months in 2013, I was paying $12 to $13 a kilogram—when fueling at the station in Emeryville, Calif. So, here’s the second rule of thumb you need:
Divide the price per kg by 2 to get a rough equivalent price for a gallon of gasoline
As you can tell, that means I was paying around $6 per gallon. Ouch. Folks using the Emeryville station tell me that they are still paying $13 per kilogram. “That’s a pretty good bogey for a near-term price,” said Tim Lipman, co-director of the Transportation Sustainability Research Center the University of California, Berkeley. “Right now things are sort of upside down with the low (for the moment) gas prices, but we see a far more competitive situation in a few years.”
Cost Curves Coming Down
In a time, when gas prices are around $3 a gallon, and home charging for electric cars is a fraction of that cost, it makes H2 look like an iffy economic proposition. But Lipman and others expect the price to come down because hydrogen infrastructure is in its infancy. As the industry matures—and economies of scale and efficient dispensing technologies are brought to bear—auto companies and fueling infrastructure firms expect the price per kg of hydrogen to drop to around $8 to $10.
In addition, the efficiency of fuel cells is getting better every year. So, the factor of 2 for doing an H2-to-gas calculation could already very well be 2.5—and soon reach 3x. This would put $9 per kg hydrogen at parity with today’s gasoline, while offering long-range driving and quick fill-ups. (Of course, the elephant in the room when it comes to hydrogen is today’s lack of infrastructure, and the glacial pace of its development.)
For the earliest of early adopters, the cost of H2 is a moot point. That’s because Toyota and other automakers are including fuel in the purchase/lease price, at least for the first couple years. Free fuel will allow drivers to take that cost out of the equation, buying time for the industry to put more stations online. This breathing room will also allow standards to emerge for precisely measuring gaseous fuel—so that you know for sure that you’re getting a full kilogram when you pay for it. Taxes and subsidies might also play a role in determining prices.
In the long-term—a tricky term that can mean a few years or a couple decades—H2 advocates are hoping for fuel at about $8 a kg. When combined with improved efficiencies, this will make hydrogen fuel-cell cars competitive with gas-powered vehicles, while providing travel with no emissions except for water vapor.