PHOTO: The steel mill in Pueblo is mentioned as one of the industries that could benefit from development of hydrogen. Photo/Allen Best
This story by Allen Best appeared on BigPivots.com on April 14, 2023 as “Hydrogen: high hopes but also skepticism. We’re sharing it in two parts.
Federal funding for hydrogen hubs was announced by the Department of Energy last September. Altogether, $7 billion will be available for 6 to 10 hydrogen “hubs” across the United States.
The money comes from an allocation of $8 billion in the Bipartisan Infrastructure Law that was passed by Congress in 2021.
Tallgrass Energy is the majority owner of a former Tri-State Generation and Transmission coal plant at Escalante, west of Albuquerque, and there it plans to produce hydrogen from natural gas, what is called “blue” hydrogen, and capture and sequester the emissions. It is developing a sequestration hub in eastern Wyoming in partnership with the State of Wyoming.
Several proposals envision electrical generation, but some also see potential to supply hydrogen to long-haul truckers.
Early in this development, Xcel would blend the hydrogen with natural gas in its existing pipelines, with the upper threshold at 10% by volume.
The proposal calls for transporting hydrogen among the four states—and beyond—using existing natural gas pipelines along established corridors through blending with the methane as well as through new, dedicated hydrogen pipelines along both existing and new corridors. Other transport mechanisms, such as a compressed gas, may also be possible.
Key connections are to include a link between Escalante in New Mexico to Brush in Colorado to Cheyenne and then to Salt Lake City. The concept paper calls this distribution and use web a “hydrogen ecosystem.”
The Front Range of Colorado will be key as 40% of the residents in the Mountain West live between metropolitan Colorado Springs and Fort Collins. Metro Denver alone has about 25% of the total population.
The location of the Pawnee Generating Station — in the windy Great Plains but close to that large market in the Front Range — seems to be crucial.
Bob Frenzel, the chief executive of Minneapolis-based Xcel, nodded at the location in his statement that the company’s project in Colorado “offers a strategic advantage with its proximity to customer end uses, generation and gas and electric distribution infrastructure, and some of the best wind and solar resources in the country for producing clean hydrogen.”
“Salt caverns, already developed in eastern Colorado for natural gas storage, are being evaluated for hydrogen storage,” the concept paper says.
Xcel only described the location as “eastern Colorado.”
At Brush, Xcel also has a 300-megawatt natural gas plant, Manchief, which was designed to meet peak demands for electricity. It plans to convert Pawnee from coal to natural gas combustion by 2026.
Colorado and other states see hydrogen as a possible way to curb emissions from otherwise hard-to-decarbonize economics sectors, including industry. For example, can clean hydrogen be deployed at the Rocky Mountain Steel mill in Pueblo or in distribution centers to fuel forklifts?
Or at the Kennecott copper mine near Salt Lake City with its 300-ton haul trucks?
Accompanying Colorado’s participation in this regional approach to hydrogen development is a proposed law, HB23-1281, “Advance the Use of Clean Hydrogen.” That bill will get its first hearing on Thursday, April 20, before the Colorado House Energy and Environment Committee.
Will Toor, the director of the Colorado Energy Office, says the legislation would do two things: create a tax credit for the use of clean hydrogen in hard-to-decarbonize sectors, including heavy transportation. It would also give the Public Utilities Commission criteria for considering any utility application for clean hydrogen investment.
“It is not absolutely essential, but it would be very useful legislation to accompany the regional hydrogen hub application,” he says. “The PUC could certainly consider an application but it gives clear criteria when considering such an application.”
That legislation would also require an assessment of the annual volume of water used in electrolysis of water to produce clean hydrogen.
Toor says relatively little water would be required for the hydrogen projects at the scale contemplated by the application for federal funding.
The federal program requires production of a minimum of 100 tons a day of hydrogen, although the production of the eight projects likely would exceed that, says Toor. The minimum, however, would require only 265 acre-feet of water annually.
“It is easy to do these calculations,” added Toor, who has a doctorate in physics. “Making one kilogram of hydrogen requires nine kilograms of water.”
The 265 acre-feet is what a 60-acre alfalfa farm in Colorado would need annually. One golf course in Boulder County uses 1,947 acre-feet annually. However, the average annual water use per golf course in Colorado is 225 acre-feet.
“At least as being contemplated right now, it’s pretty modest,” he said. Retirement of coal plants will leave more than 100,000 acre-feet available in Colorado, he pointed out, citing a March 2020 Colorado Sun story.
“So certainly it’s an issue to keep our eyes on, but at least at the scale being contemplated today, it’s probably not a major issue.”
The potential for unintended consequences in the troposphere may be a more troublesome element for hydrogen proponents. The Princeton and NOAA researchers say the problem boils down to one small, difficult-to-measure molecule known as the hydroxyl radical, or OH. It’s often been called “the detergent of the troposphere” because it plays a critical role in eliminating greenhouse gases such as methane and ozone from the atmosphere.
This radical molecule also reacts with hydrogen gas. Because there is a limited amount of OH generated each day, any spike in hydrogen emissions means that more OH would be used to break down hydrogen, leaving less OH available to break down methane.
As a consequence, methane would stay longer in the atmosphere, extending the warming impacts.
“If you emit some hydrogen into the atmosphere now, it will lead to a progressive buildup of methane in the following years,” said Princeton’s Matteo Bertagni, the first author of the research article published in Nature Communication. He’s a postdoctoral researcher working on the Carbon Mitigation Initiative.
For “green” hydrogen, i.e. that which is produced using electrolysis using renewable energy, Bertagni said the critical threshold for hydrogen emissions sits at around 9%. That means that if more than 9% of the green hydrogen produced leaks into the atmosphere — whether that be at the point of production, sometime during transport, or anywhere else along the value chain — atmospheric methane would increase over the next few decades, canceling out some of the climate benefits of switching away from fossil fuels.
And for blue hydrogen, which refers to hydrogen produced via methane reforming with subsequent carbon capture and storage, the threshold for emissions is even lower. Because methane itself is the primary input for the process of methane reforming, blue hydrogen producers have to consider direct methane leakage in addition to hydrogen leakage. For example, the researchers found that even with a methane leakage rate as low as 0.5%, hydrogen leakages would have to be kept under around 4.5% to avoid increasing atmospheric methane concentrations.
“Managing leakage rates of hydrogen and methane will be critical,” Bertagni said. “If you have just a small amount of methane leakage and a bit of hydrogen leakage, then the blue hydrogen that you produce really might not be much better than using fossil fuels, at least for the next 20 to 30 years…”
Allen Best publishes the e-journal Big Pivots, which chronicles the energy transition in Colorado and beyond.