If you want to buy an electric car in the U.S., there are more than a dozen options. If you want to buy a fuel cell car, there are three: the Honda Clarity, the Toyota Mirai, and the Hyundai ix35. But more are coming–and a new discovery in the lab might help the market expand faster.

Fuel cell cars run on hydrogen, and making hydrogen is a challenge. The traditional method of producing hydrogen (which is now typically sold to manufacturers for everything from refining metal to making margarine) starts with fossil fuels. If you heat up coal or natural gas you get hydrogen–but you also get carbon pollution. As an alternative, it’s possible to make hydrogen from water by splitting water molecules with electrolysis. It’s a clean process that produces zero pollution, but it also takes a lot of energy, and the resulting hydrogen is expensive. Catalysts like platinum can speed up the reaction and help save energy but are also expensive.

Physicists at the University of Houston have discovered a way to make the process more efficient for little cost. Their catalyst, made from cheap nickel instead of the pricey precious metals used today, helps one part of the reaction happen more easily. And if it is eventually used in production, it could mean hydrogen fuel that costs significantly less than it does today.

The cost of fuel is one of the hurdles for the technology. “Ultimately, the cost of delivered retail hydrogen is a big challenge,” says Mark Duvall, director of energy utilization at the Electric Power Research Institute, a nonprofit that has studied the technology in detail. The average cost at the tank in April 2017–from one small sample of fueling stations–was $14.10 per gallon of gasoline equivalent.

That cost for consumers also depends on factors beyond production, such as compressing the gas, transporting it, and the cost of building new stations. But if the new catalyst is used to make hydrogen from water, after more development, it could eventually help bring the cost of making it down to the level of making hydrogen from fossil fuels, and lower the total cost at the pump.

“Basically, this whole process is about finding new, cheap catalysts for an environmentally friendly process to produce hydrogen from water,” says Zhifeng Ren, a physics professor at the University of Houston and one of the authors of a new paper about the technology.