Story at a glance:
- Funded by the 2021 Bipartisan Infrastructure Law, seven regional clean hydrogen hubs (H2Hubs) will make up a national network of clean hydrogen producers, consumers, and connective infrastructure.
- H2Hubs will serve as centers for the production, storage, delivery, and use of clean hydrogen, especially meant to decarbonize heavy industry and transportation (shipping and aviation).
- If successful, H2Hubs will significantly lower the embodied carbon in steel and cement, making green buildings more sustainable.
As carbon emissions keep climbing and global average air and sea surface temperatures right along with them, the urgency to decarbonize energy production has never been greater. Using hydrogen as a fuel source is often touted as the way to decarbonize the energy sector, transportation, and heavy industries—including steel and cement.
The US Department of Energy (DOE) is planning clean hydrogen hubs as the quickest and most cost-effective way to generate the greatest amount of hydrogen in the shortest time and get it to the sectors and industries most difficult to decarbonize.
In this article we consider clean hydrogen hubs as an indirect way to make green buildings more sustainable by reducing the large amounts of embodied carbon inherent in two of the most common building materials: steel and cement.
What is Clean Hydrogen?
There are two ways to define the term clean hydrogen, according to the DOE. One refers to hydrogen produced through electrolysis, which is literally the splitting apart of water molecules into their elements (hydrogen and oxygen) by electricity generated from renewable or low-carbon emissions energy sources like wind, solar, or nuclear.
However, some energy experts further differentiate this characterization of clean hydrogen. Green hydrogen is produced through electrolysis generated from renewable energy sources (wind or solar). By contrast, pink hydrogen is produced through electrolysis generated from nuclear energy.
The DOE also describes clean hydrogen as referring to hydrogen produced using thermal conversion processes with carbon capture and storage (CCS) technologies that reduce greenhouse gas emissions.
Some energy experts refer to hydrogen produced in this manner as blue hydrogen. In this case a method known as steam methane reforming (SMR) is employed. Methane (a greenhouse gas) is split with steam into carbon dioxide (another greenhouse gas) and hydrogen. In theory the carbon dioxide is captured and stored. However, the CCS technology is not developed enough to capture and store the carbon dioxide. In fact, the nonprofit Rocky Mountain Institute (RMI) says upstream emissions of methane significantly increase the carbon footprint of blue hydrogen, and CCS technology is less than 40% efficient at capturing carbon dioxide.
Incidentally, 95% of the hydrogen produced today is gray hydrogen. Like blue hydrogen, it is generated by SMR or from coal. When coal is used, significantly more carbon dioxide emissions are released per unit of hydrogen produced, leading some to call it brown or black hydrogen instead of gray. Gray hydrogen is not clean hydrogen. It is mostly used for oil refining and ammonia (for fertilizers) production.
What is a Clean Hydrogen Hub?
The DOE describes clean hydrogen hubs (H2Hubs) as the focal points in a national network of clean hydrogen producers and consumers as well as the connective infrastructure needed to transport the hydrogen to where it will be used.
Funded by the 2021 Bipartisan Infrastructure Law, the DOE will contribute $7 billion to the hydrogen economy through the H2Hubs. The government’s H2Hubs chosen selectees at each of the seven sites will collectively contribute more than $40 billion to the program.
The three key elements of the H2Hubs program are:
1. Hydrogen Production: The H2Hubs will produce nearly 3 million metric tons of clean hydrogen per year. This quantity is roughly 30% of the US National Clean Hydrogen Strategy and Roadmap’s goal (i.e. 10 million metric tons of clean hydrogen per year by 2030).
2. Hydrogen Consumers/End Users: The primary end users of the clean hydrogen include heavy industry (e.g., steel, cement), trucking, aviation, and maritime shipping.
3. Connective Infrastructure: This includes the storage facilities, refueling stations, and pipelines needed to connect the newly created clean hydrogen supply with nearby users.
Additionally, the H2Hubs program is intended to help host communities and residents through jobs creation, better air quality, and the chance to start private businesses related to the clean hydrogen economy.
Where are H2Hubs?
The Wild Mile in Chicago is designed to be a 17-acre floating eco-park. Photo by Dave Burk
From a pool of 79 applicants, the DOE awarded the funds—conditional on meeting mandated project milestones—to seven H2Hubs. They are throughout the continental US involving 16 states. They are:
1. Appalachian Hydrogen Hub
2. California Hydrogen Hub
3. Gulf Coast Hydrogen Hub
4. Heartland Hydrogen Hub
5. Mid-Atlantic Hydrogen Hub
6. Midwest Hydrogen Hub
7. Pacific Northwest Hydrogen Hub
What types of clean hydrogen with the H2Hubs produce?
The hubs in California, the Mid-Atlantic region, and the Pacific Northwest will use electrolysis. Their energy source may be renewable energy, nuclear, or biomass.
The Gulf Coast, Heartland, and Midwest hubs will use electrolysis or SMR with CCS. Their energy sources may be renewable energy, nuclear, fossil (methane) gas, or biomass.
The Appalachian hub will use SMR with CCS. Its energy source will be fossil (methane) gas.
In other words, four of the hubs are planning on producing blue hydrogen which is not carbon-free energy because fossil (methane) gas will be used.
This fact has angered many green energy advocates who state that since the Infrastructure Law mandates only one blue hydrogen hub while all the rest should produce green hydrogen, the entire project will not allow a fast transition to carbon-free energy. For these advocates, green hydrogen is the only type of hydrogen that can be produced in a climate-neutral manner. It is essential to reaching net zero by 2050.
How long will it take to get the hydrogen hubs up and running?
USDOE projects it will take roughly seven to eight years before the hydrogen hubs are up and running.
DOE expects funding negotiations will continue during 2024. Meanwhile many hubs are not revealing details of their plans. Then the hubs will spend three to four years further developing their plans followed by up to four years of construction. Operation ramp up may take two to four years after that.
What will the H2Hubs look like when up and running?
Since the seven H2Hubs differ widely from each other, it’s not possible to be too specific on how they will operate. During his announcement of the H2Hubs awards in 2023, President Biden offered a view of what some of those operations might look like.
For example, in the mid-Atlantic hub, companies may use the vacant Delaware City Refinery and a former New Jersey jet fuel terminal to produce green hydrogen from solar energy. That hydrogen could be sent through repurposed oil pipelines to Philadelphia, to be used as fuel for heavy-duty trucks.
What do hydrogen hubs mean for the building industry?
Photo courtesy of Aeroseal
For the foreseeable future, during the next seven to eight years of build out, the H2Hubs will have no major impact on the building industry.
Currently in residential and commercial buildings electrification is an inexpensive way to lower the carbon footprint of a structure. Since the grid is used to supply the electricity, and most grid power is from fossil fuel burning, even all-electric structures won’t be totally carbon-free. Installing rooftop solar plus battery storage will reduce the carbon footprint significantly. In these cases, it’s not economically prudent to convert these buildings to run on hydrogen even if H2Hubs are close by and functioning.
However, since green hydrogen is already cheaper to produce than blue hydrogen in many places, it makes sense to convert industries that are difficult to electrify. Notably, the costs of green hydrogen production are expected to drop even further this decade. To its advantage over fossil fuels, green hydrogen is not subject to the latter’s price fluctuations and will never be subject to a tax on carbon.
But first, in order for green hydrogen to have a large role in the energy transition, investment in scaling electrolyzers must occur. So, too, must solar and wind energy expand even further than it has so that there’s ample supply to run the electrolyzers.
The H2Hubs program attempts to build out the entire supply chain of a new energy source by locating all the infrastructure and markets in a single region. So, it could attract investors when they see that there are end users close by to purchase their products.
So in the case of the building industry, green hydrogen could be best used to decarbonize the steel and cement industries on which the building industry currently depends so heavily. However, even if this were to happen, those industries should continue to reduce their carbon emissions through smart, circular design as well as by increasing energy efficiency.
Lastly, green hydrogen could be used in the building industry as a storage medium for electricity, such as that generated by solar panels or wind turbines. In this sense, green hydrogen would function like a battery, just without precious minerals.
When in excess that stored electricity could be consumed by electrolyzers to produce more green hydrogen that would then expand its storage medium capacity. In this way as a storage medium, green hydrogen would reduce the need for costly upgrades to the grid needed to supply the great demand on it caused by all-electric structures, vehicles, and data centers during and after the energy transition.
