Hydrogen is a simple, abundant element found in organic matter, notably in the hydrocarbons that make up many of our fuels, such as gasoline, natural gas, methanol, and propane. As an energy carrier like electricity (not an energy source), it must be manufactured. Hydrogen can be made by using heat to separate it from the hydrocarbons. Currently, most hydrogen is made this way from natural gas.
Hydrogen can be combined with gasoline, ethanol, methanol, or natural gas to reduce nitrogen oxide emissions. Because the only byproduct of hydrogen is water, only the engine lubricants from a hydrogen-fueled vehicle emit small amounts of air pollutants.
Hydrogen is already the fuel of choice for propelling space shuttles. It is also being explored for use in internal combustion engines. Although hydrogen can be burned in an internal combustion engine, or serve as a fuel additive, there’s more interest in using hydrogen to supply fuel cells that power EVs.