File photo: A Hyundai Tucson hydrogen fuel cell electric vehicle (FCEV). Representative image.
China, far and away the world's biggest auto market with some 28 million vehicles sold annually, is aiming for more than 1 million FCVs in service by 2030. That compares with just 1,500 or so now, most of which are buses.
Japan, a market of more than 5 million vehicles annually, wants to have 800,000 FCVs sold by that time from around 3,400 currently.
South Korea, which has a car market just one third the size of Japan, has set a target of 850,000 vehicles on the road by 2030. So far, fewer than 3,000 have been sold.
Hydrogen's proponents point to how clean it is as an energy source as water and heat are the only byproducts and how it can be made from a number of sources, including methane, coal, water, even garbage.
Resource-poor Japan sees hydrogen as a way to greater energy security.
They also argue that driving ranges and refuelling times for FCVs are comparable to gasoline cars, whereas EVs require hours to recharge and provide only a few hundred kilometres of range.
Many backers in China and Japan see FCVs as complementing EVs rather than replacing them. In general, hydrogen is seen as the more efficient choice for heavier vehicles that drive longer distances, hence the current emphasis on city buses.
Only a handful of automakers have made fuel cell passenger cars commercially available.
Including automobile giants like Toyota Motor Corp, Hyundai Motor Co, Honda Motor Co Ltd and Daimler AG.
Buses are seeing more demand. Both Toyota and Hyundai have offerings and have begun selling fuel cell components to bus makers, particularly in China.
Why haven't fuel cars caught on yet?
A lack of refuelling stations, which are costly to build, is usually cited as the biggest obstacle to widespread adoption of FCVs. At the same time, the main reason cited for the lack of refuelling infrastructure is that there are not enough FCVs to make the stations profitable.
Consumer worries about the risk of explosions are also a big hurdle and residents in Japan and South Korea have protested against the construction of hydrogen stations. This year, a hydrogen tank explosion in South Korea killed two people, which was followed by a blast at a Norway hydrogen station.
Then there's the cost. Heavy subsidies are needed to bring prices down to levels of gasoline-powered cars.
How fuel cells work?
Oxygen from the air combines with hydrogen in the fuel cell creating a chemical reaction that produces power for the electric motor.