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The intersection between nuclear energy and hydrogen is only one of the many intersections between green electrons and green molecules. Globally, the imperative for an energy transition has become increasingly critical in light of escalating CO2 emissions and soaring energy consumption. The global energy-related CO2 emissions are expected to peak around 2023 and decline by 69 percent to 11 gigatons of CO2 by 2050. In the international arena, especially post-Paris Agreement, the annual Conferences of the Parties (COP) organized by the United Nations have intensified efforts to tackle climate change. To date, 64 countries have committed to achieving net-zero emissions in the forthcoming decades.
Yet, the conversation around energy consumption remains a persistent and evolving issue. From the perspective of power consumption, the power consumption is projected to triple by 2050 as living standards grow and energy consumption per capita continues to increase. How will we meet this dramatic increase in energy demand? Alongside renewable electricity, the rise of hydrogen as a clean energy source presents a promising frontier, particularly when considering the production of hydrogen using nuclear energy. This approach could represent a significant stride in sustainable energy development, matching zero-carbon, 24/7 electricity with the production of a green molecule (hydrogen) that can be easily transported and called upon by the energy system when needed.
Nuclear power comes from nuclear fission. Nuclear power reactors use heat produced during atomic fission to boil water and produce pressurized steam. The steam is routed through the reactor steam system to spin large turbine blades that drive magnetic generators to produce electricity.
Currently, nuclear power generates around 10% of global electricity and accounts for 20% electricity generation in the US. There are over 400 nuclear power plants in operation around the world generating 367 gigawatts (GW) of power in 32 countries. A further 57 power plants are currently under construction and due to be operational by 2028. A further 213 plants are planned. As a zero emission electricity generation pathway and second largest low emission source, nuclear energy is very promising since it is a dispatchable resource that complements solar and wind resources. In 2022, 7.9 GW of new nuclear power capacity was brought online, a 40% increase on the previous year.
Nuclear power has exceptionally high energy density. To illustrate, while one kilogram of coal can yield approximately 8 kilowatt-hours (kWh) of heat energy, the same amount of uranium-235 (U-235) can produce an astounding 24 million kWh. To put it another way, one ton of U-235 can release the same amount of thermal energy as 3,000,000 tons of coal. This stark contrast underscores the remarkable efficiency of nuclear power and its potential as a sustainable energy source, especially when compared to traditional fossil fuels.
Moreover, as a dispatchable energy source, nuclear energy boasts the capability to operate continuously, 24/7, requiring refueling only every 1.5 to 2 years. This continuous operation feature sets nuclear power apart, ensuring a steady and reliable energy supply unlike intermittent sources like solar and wind. The long refueling intervals also increase the resiliency of the energy system, by helping to mitigate supply chain disruptions as it happened at the beginning of the Russo-Ukraine war. These aspects of nuclear energy not only enhance its efficiency as a low emission resource but also solidify its role as a cornerstone in the pursuit of sustainable and uninterrupted power generation.
Ambitions to reach net zero targets have encouraged innovation in nuclear power technologies such as Small Modular Reactors (SMRs), which generally have a rated capacity of under 300 megawatts (MW) per reactor, down to 10 MW (compared to more than 1,000 MW for many conventional reactors). At the 2023 G7 Summit, the United States, Japan, Korea and the United Arab Emirates announced public-private support of up to $275 million for an SMR project in Romania, expected to be deployed in 2029.
The main concern for nuclear energy is the creation of radioactive waste, whose transportation and storage requirements are still high. In addition, capital costs can be very high and the cost to construct traditional nuclear power plants is in the multi billion dollar range. High capital costs, licensing and regulation approvals, coupled with long lead times and construction delays, have also deterred public interest.
Across the different regions, the total costs, supervisory and quality assurance costs are around 15%–20%; while close to 50% of the capital costs are from civil work to prepare the site, excavations, foundations, cooling towers, and installation of the plant equipment. According to Credit Suisse’s report, they estimate the LCOE of nuclear energy to be USD 132–262 per megawatt hour. However, innovation in reactor design both for traditional and SMRs nuclear reactors bring promising cost reductions and nuclear fuel utilization while retaining the resilience, reliability and low emission profile of nuclear energy.
Hydrogen, as a clean energy carrier, has the potential to replace part of the oil and gas value chain as a transport fuel and in other applications. Hydrogen can be used in internal combustion engines or gas turbines, where it generates electricity while producing only water as a byproduct of combustion. It can be used as a long duration energy storage (LDES) solution to balance intermittent renewable energy, and can be reacted with captured CO2 to produce clean fuels and chemicals. It is also the preferred fuel for fuel cell electric vehicles (FCEVs), though portable storage at vehicle scale is a challenge. We have written extensively about Hydrogen, and you can read our views in our articles about green hydrogen (part 1 and part 2), the broader hydrogen innovation ecosystem (here and here), and about repurposing natural gas infrastructure to transport hydrogen (here).
Most hydrogen today is made by steam reforming of natural gas or coal gasification, both with carbon dioxide (CO2) emission, which is identified as gray and blue hydrogen. Future demand will be mainly for low-carbon hydrogen, referring typically to blue and green hydrogen. But pink hydrogen, that is hydrogen produced using nuclear energy (both thermal energy and electricity), represents a new frontier in the development of the clean hydrogen economy.
In fact, clean hydrogen produced with renewable or nuclear energy, or fossil fuels using carbon capture, can help to decarbonize a range of sectors, including the electricity sector itself, long-haul transport, chemicals, and iron and steel, where it has proven difficult to reduce emissions. Hydrogen-powered vehicles would improve air quality and promote energy security. Hydrogen can also support the integration of variable renewables in the electricity system, being one of the few options for storing energy over days, weeks or months. The number of announced hydrogen projects is rapidly growing now. Annual production of low-emission hydrogen could reach 38 Mt in 2030, if all announced projects are realized, with 17 Mt coming from projects at early stages of development.
There are currently four different nuclear hydrogen production methods:
Steam reforming of methane (SMR) requires temperatures of over 700 °C to combine methane and steam to produce hydrogen and carbon monoxide. A nuclear heat source would reduce natural gas consumption by about 30% (i.e. that portion of feed which would simply be used for heat), and eliminate flue gas CO2 emissions. By leveraging the heat released by the nuclear reactor, the requirements for water electrolysis can be reduced to 30-40 kWh/kg, making the hydrogen produced less expensive (since most of the cost of hydrogen produced with electricity is the electricity cost). In option 4, water is heated to high temperatures (achievable with nuclear reactors) and treated chemically to split into Hydrogen and Oxygen.
Currently 95% of hydrogen comes from natural gas, which results in carbon emissions, while the production of hydrogen using nuclear is 100% clean. The DOE’s Office of Energy Efficiency & Renewable Energy (EERE) and the Office of Nuclear Energy (NE) have already started teaming up with utilities to support three hydrogen demonstration projects at nuclear power plants.
Nine Mile Point Nuclear Power Station (Oswego, NY)
This project is a part of a $14.5 Million co-project between DOE and Constellation. DOE supported the construction and installation of a low-temperature electrolysis system at the Nine Mile Point nuclear power plant that leverages the facility’s existing hydrogen storage system. Constellation’s new Hydrogen Generation System produces hydrogen without emissions by using electricity generated at the plant to split water into hydrogen and oxygen.
The system started producing clean hydrogen in February to supply hydrogen for plant operations—a process that was previously dependent on trucked-in deliveries of hydrogen made from fossil fuels. In addition to these demonstrations, DOE is investing billions through the Bipartisan Infrastructure Law and Inflation Reduction Act to develop and mature clean hydrogen production in the United States to help lower emissions and create new job opportunities for American workers.
It also supports the Department’s Hydrogen Shot goal of reducing the cost of hydrogen by 80 percent to $1 per 1 kilogram in 1 decade.
Prairie Island Nuclear Generating Plant (Red Wing, MN)
Bloom Energy and Xcel Energy are working on a first-of-a-kind project to demonstrate high-temperature electrolysis at the Prairie Island Nuclear Generating Plant. The data collected from this demonstration will be used to scale up this process. Hydrogen production is expected to begin in early 2024.
Conclusions
Generating hydrogen from nuclear power represents a great opportunity to decarbonize the energy sector, leveraging a low-carbon, 24/7 resource to produce green molecules that can be used when and as needed by the energy system. At ECV, we are big fans of the nexus between green electrons and green molecules and look forward to working with innovators in this exciting space.
