In the best of circumstances, hydrogen can be made from electrolysis of water, powered either by solar or wind. Theoretically, it can therefore store surplus renewable power when the grid is unable to absorb it, and most critically, it can help decarbonize hard-to-electrify sectors such as long-distance transport and heavy industry. It has emerged, in part, because of our need for a solution to the intermittency of renewables.
Originally used by the Nazis to produce synthetic fuels from coal, currently– as earthquakes and climate change turn natural gas from boon to bane—there is new hope for the use of hydrogen if it can be made “clean”.
Hydrogen is not a technology, but rather an energy carrier that can be produced either clean or dirty. The climate impact depends entirely on how it is made – if from natural gas, not so clean (called “grey”), if from natural gas with carbon capture and storage, better (called “blue”), and if from the electrolysis of water powered by renewables, very fine indeed (called “green”).
Nearly all the commercial hydrogen used in America today (2023) is created via the process called steam methane reformation, in which the methane in natural gas is subjected to high-temperature steam. The conversion creates free hydrogen but also the greenhouse gas carbon dioxide as a byproduct. That’s why scientists are racing to find ways to bring down the cost of green hydrogen solutions such as electrolyzers. They apply current to water to separate it into its component elements of hydrogen and oxygen, but they remain more expensive than current technology.
Some have posited that hydrogen has a future fueling private cars, but most believe that the future of automobiles is electric, although many suggest that long haul freight will be electric plus hydrogen. Philipp Niessen, director for industry and innovation at the European Climate Foundation, predicts its most important potential lies “in sectors such as heavy industry where there is no decarbonization alternative.”
Essentially, much of the summarized information above came from an utterly brilliant, articulate, and vastly more comprehensive article written by Sonja van Renssen, on August 27, 2020, in Nature Climate Change. A PDF of the entire article is here.