The U.S. has made significant commitments to decarbonize its electricity sector by 2035 and its economy by 2050.  As the recent United Nations Intergovernmental Panel on Climate Change report highlights, following through on these commitments cannot come soon enough to combat the increasingly devastating impacts of climate change.  One theme this blog continually emphasizes is the need to use all tools at our disposal to combat climate change, including combining tools, such as renewables and nuclear power.

One very promising tool that has received a lot of attention lately, and which can be teamed with nuclear, is hydrogen production.  Nuclear power plants can supply the required heat and electricity to produce hydrogen without generating any carbon emissions.  Using nuclear in place of current energy alternatives in process heat applications, such as those required in hydrogen production, can also result in price stability and increased energy security.  Nuclear produced hydrogen can either be used as fuel for generators based on combustion or sold for industrial purposes.  As markets incorporate renewable sources of energy and the demand continues to vary – falling during the day and peaking in the early evening as people return home from work – it is becoming more difficult to sustain the supply-demand balance.  The operational flexibility and reliability enable nuclear plants to respond to seasonal demand shifts, hourly market pricing changes, and make a nuclear hydrogen combination appealing.

Increasing U.S. government support for hydrogen.  As the U.S. Government moves forward on delivering its climate change commitments, hydrogen has gained a center seat at the table discussing decarbonization of the energy, transportation, and industrial sectors—which combined account for nearly 77 percent of all greenhouse gas emissions in the U.S.  For example—

  • The White House demonstrated support for hydrogen in the American Jobs Plan, announced on March 31, highlighting hydrogen as part of the plan’s “climate-focused research” and “climate R&D priorities.” It is clear that diversifying the production and cost of clean hydrogen, a fuel that could reduce dependence on sources that emit greenhouse gases, is a priority across the federal agencies.
  • On April 8, the Department of Energy (DOE) set a goal to produce hydrogen with clean power, such as leveraging production with renewables and nuclear energy plants for production.
  • And on June 7, DOE unveiled its plan, the Hydrogen Energy Earthshot, to lower costs and advance clean hydrogen technologies by reducing the cost of clean hydrogen by 80 percent to $1 per kilogram within one decade. During the subsequent press briefing, U.S. Energy Secretary Jennifer Granholm stated “clean hydrogen is a game changer,” and that it will help “decarbonize high-polluting heavy-duty and industrial sectors, while delivering good-paying clean energy jobs.”

Further support for hydrogen appears in the Infrastructure Investment and Jobs Act (“Infrastructure Bill”), introduced by the Senate on August 1, 2021.  The Infrastructure Bill, an approximately $1 trillion bipartisan package, uniquely set a large amount of money aside for the development of hydrogen-based power systems, allocating $8 billion for a regional hydrogen hub that will produce, transport, and store lower-carbon forms of hydrogen over a five-year period.

What is hydrogen and why is it so appealing?

Hydrogen is a simple element, the lightest on the periodic table consisting of just one proton and one electron, but it can pack a powerful punch.  Hydrogen fuels the stars, including our own sun, which is the ultimate source of the vast majority of the Earth’s energy, and it can be used across different industries.  And while hydrogen can be produced – or separated – from a variety of sources, currently, close to 95 percent of hydrogen in the U.S. is produced from natural gas.  However, if produced at scale from renewables like solar, wind, or even nuclear energy, its application to other sectors will contain low carbon emissions in addition to its low carbon production.  Hydrogen’s diverse application and clean properties make it an ideal fuel alternative in the fight against climate change.

To combat climate change, hydrogen has three key uses:  energy production, industrial use, and transportation.

  • Hydrogen is useful as an energy source and fuel because it has the highest energy content of any common fuel per unit of weight – three times more than gasoline.  Additionally, hydrogen can store and deliver usable energy, and hydrogen fuel cells create immense electricity.  This is why it is used in rocket fuel and to produce electricity on some spacecraft.  To create a hydrogen fuel cell, hydrogen reacts with oxygen across an electrochemical cell similar to that of a battery to produce electricity, water, and small amounts of heat.  Many different types of fuel cells are available for a wide range of applications.  For instance, small fuel cells can power laptop computers, cell phones, and military devices, and large fuel cells can provide electricity for backup or emergency power in buildings and supply electricity in places that are not connected to electric power grids.  The electricity sector accounts for about 25 percent of greenhouse gas emissions.  Therefore, relying on hydrogen as a standalone energy source has great potential for widespread use while being an environmentally friendly alternative.
  • Industrial: Similar to energy, the industrial sector accounts for 23 percent of greenhouse gas emissions, and heavily relies on fossil fuels to create the extreme and consistent temperatures required for the production of steel, cement, and chemicals.  While wind and solar may never achieve these particular temperatures, hydrogen can, creating a significant opportunity for hydrogen.  According to DOE Alternative Fuels Data Center, the majority of hydrogen consumed in the U.S. is used by industry for refining petroleum, treating metals, producing fertilizer, and processing foods.  Companies across industrial sectors, such as ammonia, cement, ethylene, and steel companies, could bring their carbon emissions close to zero with a combination of approaches.  The most promising approaches include energy-efficiency improvements, the electrification of heat, and the use of hydrogen made with zero-carbon electricity as a feedstock or fuel.  While the optimum mix of decarbonization options will vary between sectors, in some circumstances it is cheaper to use hydrogen for fuel at newly built ammonia or steel plants than to use carbon capture storage.
  • Transportation. The transportation industry accounts for nearly 29 percent of greenhouse gas emissions, making it an ideal candidate for the incorporation of hydrogen. The interest in hydrogen as a transportation fuel is based on its potential for domestic production and use in fuel cells for high efficiency, zero-emission electric vehicles.  As mentioned, a fuel cell is two to three times more efficient than an internal combustion engine running on gasoline.  And several S. vehicle manufacturers have begun making light-duty hydrogen fuel cell electric vehicles available in select regions of California where there is access to hydrogen fueling stations.  Most hydrogen-fueled vehicles are automobiles and transit buses that have an electric motor powered by a hydrogen fuel cell, and few of these vehicles burn hydrogen directly.  The high cost of fuel cells and the limited availability of hydrogen fueling stations have limited the number of hydrogen-fueled vehicles.

While there are other sectors that could contribute to decarbonization commitments, the above three are currently the largest greenhouse gas emitters and sectors where hydrogen-use will demonstrate quantifiable and tangible impacts.  For instance, for the energy industry, when faced with unpredictable weather events, hydrogen will be critical to strengthening the nation’s grid system.  For the industrial sector, hydrogen is used in refining petroleum, treating metals, producing fertilizer, and is a prime ingredient in rocket fuel.  And for transportation, when hydrogen is combusted in an engine or consumed in a fuel cell, it combines with oxygen to form water.  Thus, a car running on hydrogen is primarily emitting water vapor as a waste product.

The Catch?  Hydrogen has a dirty secret.  Despite its immense promise, hydrogen’s dirty secret is that hydrogen’s carbon footprint really depends on how the hydrogen is produced.  In fact, there is an entire color spectrum of types of hydrogen classified by the way it is produced.  Since hydrogen is not found in free form (H2), it must be separated from other molecules like water or methane, using energy sources.  Nearly all hydrogen currently comes from energy produced with fossil fuels or natural gas, where it is bonded with carbon, separated by a process called “steam reforming” and the excess carbon generates carbon dioxide.  This type of hydrogen is referred to as “grey” hydrogen to indicate it was created from fossil fuels without capturing the greenhouse gases.  Its widespread use in industrial processes makes grey hydrogen one of the most common forms, accounting for roughly 95 percent of the world’s production and emitting about 9.3kg of CO2 per kg of hydrogen production.  With that said, if hydrogen is produced using fossil fuels, we won’t be able to transition away from fossil fuels and it still releases significant carbon dioxide and other greenhouse gases into the atmosphere.

To combat climate change and reach decarbonization, the hydrogen production process itself must be clear—and therefore, the current challenge is to produce hydrogen in a more environmentally friendly way.  Luckily, hydrogen can be produced with lower-carbon methods.  For example—

  • Hydrogen is considered “blue” when the emissions generated from the steam reforming process are captured and stored underground by industrial carbon capture and storage. While blue hydrogen reduces CO2 emissions, 10-20 percent of the CO2 is not captured, and so while it is a “low carbon” option, it does not go far enough to meet the commitments for reducing greenhouse gas emissions.
  • Green hydrogen is produced using electricity generated from renewables and currently accounts for 1 percent of hydrogen production. Green hydrogen is a more environmentally-friendly option compared to grey and blue because wind, solar and hydro power are zero-carbon sources.  However, it may be difficult to achieve widespread deployment for this type of hydrogen production because of the intermittent nature of renewables and the cost.  Despite its decarbonization potential, green hydrogen must achieve cost competitiveness. In 2020, the pricing for green hydrogen was around US$6.00 per kg and a Hydrogen Council study identified US$2.00 per kg as the price point that will make green hydrogen and its derivative fuels the energy source of choice.
  • Finally, pink hydrogen is used to describe hydrogen obtained through nuclear energy which emits virtually no pollutants. In fact, an Applied Energy study concluded that hydrogen produced via nuclear energy has a comparable carbon footprint to hydrogen produced with renewables.

Advantages of combing nuclear power with hydrogen.  Hydrogen is increasingly seen as a key component of future energy systems if it can be made without carbon dioxide emissions.  Support for this endeavor is demonstrated by the “Clean Hydrogen Research and Development Program” and the clean hydrogen hubs established in the Infrastructure Bill.  For example, the Infrastructure Bill provides US$8 billion in spending to create at least four “regional clean hydrogen hubs” producing and using the fuel for manufacturing, heating and transportation.  At least two would be in U.S. regions “with the greatest natural gas resources,” and at least one of the regional clean hydrogen hubs is required to demonstrate the production of clean hydrogen from nuclear energy.

There is a clear push for the production of clean hydrogen to come from diverse energy sources, to include nuclear energy.  For instance, the Infrastructure Bill includes a section called “National Clean Hydrogen Strategy and Roadmap” which requires the identification of (1) economic opportunities for the production, processing, transport, and storage of clean hydrogen that exist for merchant nuclear power plants operating in deregulated markets, (2) the environmental risks associated with deploying clean hydrogen technologies in those regions, and (3) mitigation of those risks.

In addition to the nuclear hydrogen hub in the Infrastructure Bill, DOE has partnered with a number of nuclear power plants to demonstrate the technical feasibility and business justification for hydrogen production at nuclear facilities.  For instance—

  • Arizona Public Service Co. is currently working with Idaho National Laboratory (INL) to employ advanced hydrogen production from surplus electricity at the Palo Verde Generation Station.
  • Exelon Generation announced its plan to work with DOE on a hydrogen production demonstration project at Nine Mile Point, where a containerized Proton Exchange Membrane electrolyzer will be installed using the plant’s existing hydrogen storage system to capture and store hydrogen for industrial applications in the market.
  • FirstEnergy Solutions and INL will develop a light water reactor hybrid energy system to demonstrate hydrogen production at the Davis-Besse Nuclear Plant. And NuScale is investigating cogeneration options, including hydrogen production by high-temperature steam electrolysis with INL.

Acknowledging the low carbon footprint associated with using nuclear energy for hydrogen production, DOE selected projects to advance flexible operations of nuclear reactors with integrated hydrogen production systems.  These projects include low-temperature steam electrolysis, which improves the efficiency of electrolysis at ambient temperatures and utilizes waste heat at up to 200°C from a conventional reactor, and high-temperature steam electrolysis (HTSE) to use both heat and electricity.

Another one of the DOE projects involves INL working with Xcel Energy to demonstrate HTSE technology using heat and electricity from one of Xcel Energy’s nuclear plants.  DOE’s Expressions of Interest for this project were discussed in a previous blog post.

Nuclear power plants and hydrogen production systems are well aligned to give nuclear an economical and environmental advantage over traditional hydrogen production energy sources.  This is because nuclear energy can supply the heat and electricity required for hydrogen production without generating carbon emissions, which may create largescale opportunities for nuclear energy. Largescale opportunities would in turn, provide an additional revenue stream, potentially reviving aging fleets in certain markets and creating more time to get advanced reactors online.  According to an Energy Options Network study, meeting the energy demands of the U.S. maritime transportation industry by 2050 alone, would require 650 gigawatts of advanced nuclear reactors for hydrogen production.

Advanced nuclear power plants are evolving and undergoing technological advances to make them more flexible.  At the same time, hydrogen generation is undergoing technical advances to become more versatile, and as the energy market evolves, hydrogen production is gaining global visibility and political support.

There are already international nuclear-hydrogen initiatives underway. The IAEA has developed the Hydrogen Economic Evaluation Program (HEEP) to assess the economics of large-scale hydrogen production using nuclear energy.  And in February 2021, the United Kingdom Nuclear Industry Association published the Hydrogen Roadmap, showing how the country might achieve 225 TWh (6.8 or 5.7 Mt) of low-carbon hydrogen by 2050.  The Roadmap proposes 12-13 GW of nuclear reactors of all types using high-temperature steam electrolysis and thermochemical water-splitting to produce 75 TWh (2.3 or 1.9 Mt) of hydrogen by mid-century.  Additionally, Russia is planning a new hydrogen industry by 2024, where Rosatom will produce hydrogen by electrolysis and is planning 1 MW of electrolyzed capacity at the Kola nuclear power plant in 2023, then increasing it to 10 MW as a demonstration project for wider adoption.

The promise of decarbonization and a cleaner, greener energy future is within reach.  This is especially true when looking at the collaboration between the public and private sectors, both domestically and abroad.  Leveraging all available carbon-free sources for hydrogen production, including nuclear, will just be another big step in the caron-free direction.

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