The private and public sectors are seeking to use the nation's nuclear power plants as engines of the emerging hydrogen economy.

The idea would be to harness heat and electricity from nuclear power plants to produce green hydrogen, helping to commercialize the zero-carbon gas and drive down its cost. At the same time, nuclear power plants would benefit from a new income stream by selling hydrogen into industries that are trying to decarbonize.

For some nuclear power plants struggling to compete in regional capacity markets, hydrogen could be a lifeline, according to Bruce Halbert, director of the light water reactor sustainability program at the U.S. Energy Department's Idaho National Laboratory.

"Some of the utilities we're working with, their plants have not even cleared the auctions to produce the electricity, so they have no long-term power purchase agreements," Halbert said during a Jan. 15 webinar hosted by the United States Energy Association. "And so we see for some of these plants, and others, that hydrogen can be a key part of their financial future."

Potential offtakers in different industries

Many companies pursuing green hydrogen opportunities plan to leverage low-temperature electrolysis, which uses zero-carbon electricity to split water into hydrogen and oxygen. However, nuclear power plants provide the option of high-temperature electrolysis, a less mature technology that requires the heat energy that nuclear facilities can supply.

The Energy Department has partnered with several nuclear power plant operators — including Pinnacle West Capital Corp. subsidiary Arizona Public Service Co., Xcel Energy Inc., Exelon Corp. and Energy Harbor Corp. — to demonstrate the technical feasibility and business case for producing green hydrogen from their facilities. According to Halbert, some of the projects are well along the way to addressing the technical, regulatory and safety issues associated with hydrogen production at commercial nuclear power sites.

The next step is moving from 2-MW of hydrogen production towards 25-MW, eventually reaching the 100-MW to 500-MW range, Halbert said. For some plants, the long-term economic case might be utilizing their full energy capacity to produce hydrogen, particularly where local demand centers exist, he added.

"I think we'll also see these nuclear power plants develop into energy parks, with offtake users situated nearby to use the hydrogen nearest the source of generation," Halbert said. "It's quite possible that nuclear power plants, more than supplying electricity, will become part of the supply chain to other industries, whether it is steel manufacturing near the Toledo area, supplying clean hydrogen and domestic sources of hydrogen for commercial bus fleets and cities, to supplying hydrogen for fertilizer, synthetic fuels and other types of things in the future."

Arizona Public Service has not yet determined which industries would buy hydrogen produced from its nuclear fleet, according to Michael Green, the company's general manager for nuclear power. However, in addition to selling into the industries Halbert listed, the company also sees potential to decarbonize its own natural gas-fired power plants by blending hydrogen into its fuel mix.

Green supplies from nuclear complement blue hydrogen

Using the nation's nuclear fleet could circumvent some of the challenges to developing the hydrogen economy presented by blue hydrogen, according to panelists. Blue hydrogen relies on fossil fuel-based steam methane reforming, but captures and sequesters emissions during the production process.

Hydrogen storage and transportation costs are manageable where existing infrastructure already exists, Green said. That includes the Texas Gulf Coast petrochemical hub, where much of today's hydrogen is consumed and a limited network of dedicated infrastructure exists. However, that infrastructure is not available throughout much of the U.S., Green said.

Hydrogen can be stored in salt caverns, but underground storage owners and operators say the current economic framework is not sufficient to encourage them to convert or develop geological reservoirs to store not only hydrogen, but carbon captured during blue hydrogen production, according to Mark Eisenhower, a partner in the energy, sustainability and infrastructure practice at consulting firm Guidehouse.

To be sure, renewable hydrogen is not yet cost-competitive with standard supplies derived from fossil fuel inputs, and panelists could not offer a clear path to commercial viability. However, Halbert is optimistic about the potential to scale nuclear applications.

"We expect to see commercial level scales in the nearer term," he said. "I don't think this is a far off in the future type of proposition."