It’s the buzzword of the energy world right now: green hydrogen. This fuel is being touted as a means to decarbonize long-haul transportation, heavy industry such as steelmaking and oil refining, and agricultural fertilizer production. Depending on how it’s made, green hydrogen may be a helpful part of our future clean energy mix and provide an option for long-term energy storage.
What is green hydrogen, and how does it work?
Different Hydrogen Types
Hydrogen power is already used today as an energy source and for energy storage. For example, the National Renewable Energy Laboratory (NREL) shows that using hydrogen for electricity via fuel cells makes sense for storage applications with a duration of 13 hours or more. Fuel cells may also be used to power long-distance vehicles.
But the hydrogen most popularly used for energy is not often considered “clean.” The most common method of producing hydrogen uses steam and methane from fracked gas to extract hydrogen from water. This steam reformation process results in what’s known as “gray hydrogen,” but also generates copious amounts of climate-damaging carbon dioxide and methane.
So-called “blue hydrogen” also is derived from fossil fuels, while some of its emissions are captured and sequestered. But this isn't a clean alternative, either; there are still opportunities for methane leakage, and sequestration is an uncertain method of reducing carbon dioxide. Much of what is captured is used to force more fracked gas out of the ground.
Green hydrogen is a zero-emissions option, as it’s split from water using electricity from renewable sources. Currently, green hydrogen accounts for only one percent of total hydrogen production. If that is increased, however, the fuel could be a game changer for industries and applications that are otherwise difficult to decarbonize.
But it does have shortcomings - especially its low density, which makes transportation difficult. The gas must be cooled and liquified or compressed for delivery via pipelines, and there are only around 1,600 miles of hydrogen pipeline currently in the United States. The current “hubs” for hydrogen use are located far from production sites. Adding new pipelines raises environmental, safety and equity concerns.
President Biden’s Initiatives for Green Hydrogen
The Biden administration has promised to create a green hydrogen market over the next decade that provides fuel at the same price as conventional hydrogen. The Bipartisan Infrastructure Law passed in November 2021 included $9.5 billion to support a clean hydrogen industry and, this month, the Department of Energy (DOE) is launching initiatives using this funding.
Currently, $8 billion is allocated for four Regional Clean Hydrogen Hubs, defined as "a network of clean hydrogen producers, potential clean hydrogen consumers, and connective infrastructure located in close proximity.” These are expected to help set a clean hydrogen production standard and manage production, processing, delivery, storage, and end-use of clean hydrogen. Hubs will specialize in production from different fuel sources, and target specific end uses such as electricity generation, the industrial sector, residential and commercial heating, and transportation.
An additional $1 billion will fund a Clean Hydrogen Electrolysis Program that aims to reduce the costs of hydrogen produced by clean energy; green hydrogen is not yet cost-competitive with dirtier fuels. Gray hydrogen runs in the ballpark of $1 to $2 per kilogram, while blue hydrogen costs about $2.40 per kilogram. Green hydrogen, on the other hand, can run up to around $6.55 per kilogram. The Electrolysis Program seeks to reduce clean hydrogen costs to less than $2 by 2026.
Lastly, the Infrastructure Law includes $500 million for clean hydrogen manufacturing and recycling initiatives. This seeks to support domestic supply chains and equipment manufacturing using clean fuel. The funding is meant to encourage American production of clean hydrogen equipment, cost-effective clean hydrogen supply, and innovation around reusing and recycling clean hydrogen technologies.
Green Hydrogen Regionally and in NC
At the regional level, the Southeast Hydrogen Energy Alliance has teamed with E4 Carolinas to drive commercialization of hydrogen in the Southeast United States. The goal of these convenings is to bolster general hydrogen opportunities, not solely green hydrogen.
In North Carolina, Duke Energy’s 2020 Integrated Resource Plan (IRP) includes the possibility of green hydrogen as an energy source. The company notes that meeting its net-zero carbon by 2050 goal will require use of “zero emissions load following resources” (ZELFR) technologies, including green hydrogen. Duke’s vision includes ZELFR tech producing around 16 percent of its power by 2040 and comprising 30 percent of a net zero fleet in 2050. The company is partnering with Siemens and Clemson University to study green hydrogen storage.
Could Utilities Bet Too Heavily on Green Hydrogen?
Duke Energy’s 2020 IRP indicates that the company plans to continue fracked gas expansion in the coming decades, which Sierra Club opposes. The company explicitly mentions the potential for green hydrogen to extend the life of fracked gas technology, which involves utilizing gas in a 90/10 blend with green hydrogen. Transporting and using higher quantities of hydrogen would rely on retrofits to existing infrastructure and/or entirely new turbines. The addition of green hydrogen to North Carolina’s energy mix could be an environmental benefit overall, but not if it’s used to extend the life of uneconomic fracked gas plants that contribute to climate change, or to add new gas plants.
It is also worrisome that both the Biden Administration and Duke Energy’s plans for hydrogen use center on “clean hydrogen,” which may not be completely “green” or carbon free. Many green hydrogen advocates worry that “clean" hydrogen proliferation will employ blue hydrogen. In fact, the hydrogen portion of the national Infrastructure Law already spotlights the blue option.
Investment in hydrogen technology that requires fossil fuel feedstock runs the risk of burning more fracked gas, which would exacerbate climate change. Hydrogen should not be used to give dirty energy industries a lifeline to operate fossil infrastructure long into the future.
The crucial question about hydrogen is where does it come from and how is it made? The answers to those questions determine how environmentally beneficial it is - or isn't. If we are to increase the use of hydrogen for energy, we should only consider hydrogen produced from renewable, greenhouse gas-free industries.
The Sierra Club only supports the use of green hydrogen. But it's costly to produce, transport and use, and resources to develop its use are scanty. It will take the right policy initiatives and market innovation to make green hydrogen a legitimate "clean" option for our energy future. But it's one worth exploring as we try to meet energy demand in a world that also demands environmentally sound choices.