The new era of hydrogen vehicles

A hydrogen vehicle is a type of alternative fuel vehicle that uses hydrogen fuel for motive power. Hydrogen vehicles include hydrogen-fueled space rockets, as well as automobiles and other transportation vehicles. Power is generated by converting the chemical energy of hydrogen to mechanical energy, either by reacting hydrogen with oxygen in a fuel cell to power electric motors or, less commonly, by burning hydrogen in an internal combustion engine.

As of 2021, there are two models of hydrogen cars publicly available in select markets: the Toyota Mirai (2014–), which is the world's first mass-produced dedicated fuel cell electric vehicle (FCEV), and the Hyundai Nexo (2018–). The Honda Clarity was produced from 2016 to 2021. Most companies that had been testing hydrogen cars have switched to battery electric cars; Volkswagen has expressed that the technology has no future in the automotive space, mainly because a fuel cell electric vehicle consumes about three times more energy than a battery electric car for each mile driven. As of December 2020, there were 31,225 passenger FCEVs powered with hydrogen on the world's roads.

As of 2019, 98% of hydrogen is produced by steam methane reforming, which emits carbon monoxide. It can be produced by thermochemical or pyrolytic means using renewable feedstocks, but the processes are currently expensive. Various technologies are being developed that aim to deliver costs low enough, and quantities great enough, to compete with hydrogen production using natural gas.

The benefits of hydrogen technology are fast refueling time and long driving range on a single tank. The drawbacks of hydrogen use are high carbon emissions when hydrogen is produced from natural gas, capital cost burden, low energy content per unit volume at ambient conditions.

Automobiles, buses, forklifts, trains, PHB bicycles, canal boats, cargo bikes, golf carts, motorcycles, wheelchairs, ships, aeroplanes, submarines, and rockets can already run on hydrogen, in various forms. NASA used hydrogen to launch Space Shuttles into space. A working toy model car runs on solar power, using a regenerative fuel cell to store energy in the form of hydrogen and oxygen gas. It can then convert the fuel back into water to release the solar energy. Since the advent of hydraulic fracturing the key concern for hydrogen fuel cell vehicles is consumer and public policy confusion concerning the adoption of natural gas powered hydrogen vehicles with heavy hidden emissions to the detriment of environmentally friendly transportation.

As of 2021, there are two hydrogen cars publicly available in select markets: the Toyota Mirai and the Hyundai Nexo. The Honda Clarity was produced from 2016 to 2021.