Hydrogen use is currently dominated by industry, oil refining, ammonia production, methanol production and steel production. Hydrogen is predominately supplied using fossil fuels, so there is significant potential for emissions reductions from clean hydrogen.
The interest in hydrogen as a transportation fuel is based on its potential for production and use in fuel cells for high efficiency, zero-emission electric vehicles. A fuel cell is two to three times more efficient than an internal combustion engine running on gasoline. Hydrogen use in vehicles is a major focus of fuel cell research and development. Hydrogen and oxygen have therefore been used as rocket fuel for decades, not because of a benefit to the environment but because the full weight of the fuel is ignited.
Several vehicle manufacturers have begun making light-duty hydrogen fuel cell electric vehicles available in select regions where there is access to hydrogen fueling stations. The global fuel cell electric vehicle (FCEV) stock reached 11,200 units at the end of 2018, with sales of around 4,000 in that year (80% more than in 2017).
China's presence in FCEVs expanded significantly in 2018, with up to 2 000 small trucks produced. However, as these vehicles wait for the corresponding refueling infrastructure, just 400 were registered for road use in 2018.
Hydrogen fuel cells produce electricity by combining hydrogen and oxygen atoms. This combination results in an electrical current. Many different types of fuel cells are available for a wide range of applications. Small fuel cells can power laptop computers, cell phones, and military applications. Large fuel cells can provide electricity for emergency power in buildings and in remote areas that are not connected to electric power grids. Hydrogen use in vehicles is a major focus of fuel cell research and development.