Why BMW is betting on hydrogen fuel cell powertrains

BMW has committed to building a series production hydrogen fuel cell car, even as other automakers focus on using hydrogen to fuel internal combustion engine vehicles.

The automaker said Sept. 5 that it would launch the fuel cell vehicle in 2028, working with Toyota to develop a "next-generation" powertrain using that company's fuel cells. BMW has not said which car will get the technology, but it has been testing iX5 crossovers with fuel cells in 20 countries and producing the model on a limited basis at its factory in Munich.

The hydrogen drivetrain could be an option for a vehicle built on the coming Neue Klasse electric-only architecture. Michael Rath, vice president of hydrogen vehicles at BMW, said the Neue Klasse underpinnings are well suited for fuel cells.

The Toyota Mirai sedan is one of the few fuel cell light vehicles sold in the U.S. Another is the Hyundai Nexo crossover. Neither is a big seller: In 2023, Toyota sold 2,737 Mirais in the U.S., while Hyundai sold 241 Nexos, according to the Automotive News Research & Data Center.

BMW is no stranger to hydrogen. It has used liquid hydrogen in a number of internal combustion test vehicles, starting with a 5 Series in 1979. In the mid-2000s, the automaker sold a version of the 7 Series sedan with a hydrogen-powered V-12 engine.

Toyota as well as Renault's Alpine brand are backing hydrogen-powered ICE cars, but neither has announced production plans.

Rath said BMW shifted its efforts to fuel cells after decades of working with hydrogen-powered combustion engines partly for practical reasons.

"When we had diesel and gasoline engines, we were seeking commonality and interchangeability between combustion and hydrogen cars," he said during a media roundtable. "We tried to bring hydrogen into existing architectures and components."

Now, BMW is doing the same thing with battery-electric drivetrains, Rath said. Its fuel cell vehicles will use the same electric motors and other components as BEVs.

"We want to be flexible and leverage the synergies between the two," he said, especially because BMW sees fuel cell vehicles and BEVs as complementary decarbonization technologies.

A process called hydrolysis occurs in a fuel cell, using hydrogen from a tank and oxygen to create electricity, which either directly drives the motor or charges the battery. Because they carry a fuel source on board, the vehicles can use smaller batteries. The only emissions are water vapor. Like BEVs, fuel cell vehicles benefit from regenerative braking.

Hydrogen fuel cell powertrains have a number of advantages over BEVs, Rath said. They offer all the advantages of electric driving with quick refueling time, especially important for high-mileage users or those who need to tow trailers. In addition, heating and cooling don't affect the range as much as they do in a BEV.

Fuel cell vehicles "are ideal for customers who don't have convenient charging at home or work or those who travel a lot and can't plan their lives around charging. These are not competing technologies," Rath said.

The main difference is that the energy is stored in hydrogen, while in a BEV, it is stored in the battery, he said.

Still, fuel cell vehicles face hurdles to wider adoption. There are just 55 public hydrogen filling stations in the U.S., all in California, according to the Department of Energy. And consumers complain that many are broken or out of fuel. Indeed, there are only about 1,000 hydrogen pumps worldwide.

Moreover, hydrogen-powered vehicles are only beneficial to the environment when they run on green hydrogen, which is made with renewable energy rather than fossil fuel energy such as natural gas. But almost no green hydrogen is available, and analysts say it will take years and massive investment to create a supply chain.

Another challenge is the relative inefficiency of using hydrogen versus electricity as EV energy.

Sustainably made hydrogen is likely to be produced near wind or solar sources in sunny and windy climates, such as coastal regions, that are far from developed areas where the vehicles will be used. Electricity is first converted into hydrogen, which is then transported and then converted back into electricity to power a vehicle, resulting in energy losses. But BEVs use electricity directly, with one best-case scenario being a car charged directly from a home that is powered by solar panels.

Rath said that on an individual "well-to-wheel" basis, "it's a fact that BEVs are more efficient." But, he argues, a wider view of an EV's life cycle that accounts for raw materials, production and even recycling shows that fuel cells and BEVs have "comparable footprints."

And, because hydrogen is an ideal carrier for sustainable energy, he said, it can be used to maximize solar and wind energy production. Instead of surplus energy being wasted, Rath said, it can be used to generate green hydrogen, which can then be transported elsewhere.

"A lot of industries around the world will need to import renewables from regions far away, with hydrogen as the transport medium," he said.