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—
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.
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—
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—
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.