Hydrogen is an energy carrier and molecules containing hydrogen must be broken apart and the hydrogen captured to be used. However, not all hydrogen is created equal when it comes to climate impacts. The type of electricity used or the molecular hydrogen source is the determining factor in producing “clean” hydrogen.
How is hydrogen commonly produced today?
Most hydrogen today is made by converting methane from natural gas or renewable sources to carbon dioxide (CO2) and hydrogen using a process called steam-methane reforming. While methane from anaerobic digesters or other renewable sources can generate hydrogen with low emissions, most hydrogen produced by steam-methane reforming emits a lot of CO2 – about 10 kilograms for every 1 kilogram of hydrogen.
But there is another way – a cleaner way – to produce hydrogen by using renewable electricity like solar, wind or hydropower to split water.
Electrolysis – the key to producing clean hydrogen.
The process of using electricity to split water into hydrogen and oxygen is called electrolysis. The electric charge splits the water molecules into hydrogen and oxygen atoms, as shown in the graphic. And when you use renewable energy, carbon emissions are not produced during this process, resulting in clean hydrogen.
We are fortunate to have an abundant supply of clean electricity – from hydroelectric dams, wind, and solar – in the Pacific Northwest. No other part of the country can match our clean electricity supply.
Clean hydrogen production is a key pathway to achieving the U.S. Department of Energy’s Hydrogen Energy Earthshot, which “seeks to reduce the cost of clean hydrogen by 80% to $1 per 1 kilogram in 1 decade.”
In this video, U.S. Energy Secretary Jennifer Granholm explains clean hydrogen and how the agency is making it a reality.