Aug. 13, 2021
By Rachel Koning Beals
Report titled ‘How Green is Blue Hydrogen?’ generates buzz, and pushback, as Biden, Congress and Wall Street promote the energy source in path toward zero emissions
One of the world's first plants for the production of climate-friendly hydrogen by Anglo-Dutch oil giant Shell is in Germany. A new study takes aim at the energy source touted by President Joe Biden, the International Energy Agency and some major energy companies. AFP/GETTY IMAGES
Clean hydrogen is a fuel the Biden administration believes will be part of the toolkit necessary to propel the U.S. to zero emissions by 2050, not to mention a 50% cut in those emissions as soon as the end of this decade. But a peer-reviewed study out Thursday argues that the fuel’s credentials need reconsideration.
Some energy-industry and clean-air analysts raised their own concerns that the study, published in the Energy Science & Engineering journal by researchers from Cornell and Stanford Universities, misapplied short-term findings to a long-term view, made other flawed assumptions, and risked sidelining the evolving technology prematurely.
Hydrogen is already used in some applications but has historically been too expensive to directly replace fossil fuels. The International Energy Agency, in an anti-oil report that surprised many earlier this year, has factored in hydrogen’s role in the new-energy world.
Most hydrogen used today is extracted from natural gas NG00, -2.14% in a process that emits carbon dioxide as well as the more-fleeting, but more-potent, methane. It’s these emissions that the study mostly focuses on.
The researchers, Robert Howarth, a biogeochemist and ecosystem scientist at Cornell, and Mark Jacobson, a professor of civil and environmental engineering at Stanford and director of its Atmosphere/Energy program, examined the lifecycle greenhouse-gas emissions of “blue” hydrogen, accounting for emissions of both carbon dioxide and unburned, fugitive methane (The U.N. has stepped up its concerns that methane be addressed sooner than later).
As the natural-gas industry looks toward more hydrogen production, it pushes capturing emissions, which then leaves “blue” hydrogen, as the industry calls it. That’s short of “green,” but still curtails the pollution. “Green” hydrogen would ultimately need to be made using zero-emissions renewable energy, such as wind or solar, and electrolyzing water to separate hydrogen atoms from oxygen. Renewable energy is not yet common enough — although it is getting more cost competitive — to replace natural gas in this process.
The paper argues that across the “blue” hydrogen supply chain, the process actually emits more than simply burning natural gas for its traditional uses.
The researchers accounted for carbon dioxide emissions and the methane that leaks from equipment during natural-gas production. They assumed that 3.5% of the gas drilled from the ground leaks into the atmosphere, basing that percentage on mounting research that argues natural-gas drilling puts off more methane than previously known. And they added in the natural gas required to power the carbon-capture technology.
In total, they found that the greenhouse-gas footprint of blue hydrogen was more than 20% greater than just burning natural gas or coal for heat, and 60% more than burning diesel oil for heat.
“Our analysis assumes that captured carbon dioxide can be stored indefinitely, an optimistic and unproven assumption,” they said. “Even if true though, the use of blue hydrogen appears difficult to justify on climate grounds.”
Report titled ‘How Green is Blue Hydrogen?’ generates buzz, and pushback, as Biden, Congress and Wall Street promote the energy source in path toward zero emissions
One of the world's first plants for the production of climate-friendly hydrogen by Anglo-Dutch oil giant Shell is in Germany. A new study takes aim at the energy source touted by President Joe Biden, the International Energy Agency and some major energy companies. AFP/GETTY IMAGES
Clean hydrogen is a fuel the Biden administration believes will be part of the toolkit necessary to propel the U.S. to zero emissions by 2050, not to mention a 50% cut in those emissions as soon as the end of this decade. But a peer-reviewed study out Thursday argues that the fuel’s credentials need reconsideration.
Some energy-industry and clean-air analysts raised their own concerns that the study, published in the Energy Science & Engineering journal by researchers from Cornell and Stanford Universities, misapplied short-term findings to a long-term view, made other flawed assumptions, and risked sidelining the evolving technology prematurely.
Hydrogen is already used in some applications but has historically been too expensive to directly replace fossil fuels. The International Energy Agency, in an anti-oil report that surprised many earlier this year, has factored in hydrogen’s role in the new-energy world.
Most hydrogen used today is extracted from natural gas NG00, -2.14% in a process that emits carbon dioxide as well as the more-fleeting, but more-potent, methane. It’s these emissions that the study mostly focuses on.
The researchers, Robert Howarth, a biogeochemist and ecosystem scientist at Cornell, and Mark Jacobson, a professor of civil and environmental engineering at Stanford and director of its Atmosphere/Energy program, examined the lifecycle greenhouse-gas emissions of “blue” hydrogen, accounting for emissions of both carbon dioxide and unburned, fugitive methane (The U.N. has stepped up its concerns that methane be addressed sooner than later).
As the natural-gas industry looks toward more hydrogen production, it pushes capturing emissions, which then leaves “blue” hydrogen, as the industry calls it. That’s short of “green,” but still curtails the pollution. “Green” hydrogen would ultimately need to be made using zero-emissions renewable energy, such as wind or solar, and electrolyzing water to separate hydrogen atoms from oxygen. Renewable energy is not yet common enough — although it is getting more cost competitive — to replace natural gas in this process.
The paper argues that across the “blue” hydrogen supply chain, the process actually emits more than simply burning natural gas for its traditional uses.
The researchers accounted for carbon dioxide emissions and the methane that leaks from equipment during natural-gas production. They assumed that 3.5% of the gas drilled from the ground leaks into the atmosphere, basing that percentage on mounting research that argues natural-gas drilling puts off more methane than previously known. And they added in the natural gas required to power the carbon-capture technology.
In total, they found that the greenhouse-gas footprint of blue hydrogen was more than 20% greater than just burning natural gas or coal for heat, and 60% more than burning diesel oil for heat.
“Our analysis assumes that captured carbon dioxide can be stored indefinitely, an optimistic and unproven assumption,” they said. “Even if true though, the use of blue hydrogen appears difficult to justify on climate grounds.”
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