Green Hydrogen
Overview
Falling costs for hydrogen produced with renewable energy, combined with the urgency of cutting greenhouse-gas emissions, has given clean hydrogen unprecedented political and business momentum. Its potential role for the energy transition and the road to net zero has raised high expectations over the last years and months.
This article sheds a light on (green) hydrogen, its use, market and costs, as well as its advantages and disadvantages.
What is Hydrogen?
Hydrogen is the simplest and lightest element as well as the most abundant element in the universe. Each atom of hydrogen has only one proton and one electron. Hydrogen occurs naturally on earth only in compound form with other elements in liquids, gases, or solids. Hydrogen combined with carbon (hydrocarbons) exists in petroleum, natural gas, and coal. Hydrogen combined with oxygen is water (H2O).[1][2]
As a secondary source of energy, hydrogen carries energy produced from other resources like fossil fuels, water, or biomass. To produce hydrogen by separating it from other elements, it needs more energy than hydrogen provides when converted to useful energy. Hydrogen has the highest energy content of any common fuel by weight (about three times more than gasoline), but it has the lowest energy content by volume (about four times less than gasoline). [1]
It is very clean-burning and when combined with oxygen in a fuel cell, hydrogen produces heat and electricity with only water vapor as a by-product.[3]
