Hydrogen is the simplest and most abundant element in the universe, made up of just one proton and one electron. It’s a clean energy carrier that can be used as a fuel without producing carbon emissions—when used, it combines with oxygen to produce water. Hydrogen can be produced in various ways, including from natural gas, water (via electrolysis), or renewable sources. Because it stores a lot of energy by weight, hydrogen is gaining attention as a key part of the future energy mix, especially for transportation, industry, and power storage. Other forms of energy are usually required to produce it. However, once made, hydrogen can be used as a zero-carbon fuel when combusted with oxygen, with only water vapor as a byproduct. It is versatile and can power fuel cells or internal combustion engines, generating clean power or heat on-site.