Paul Lalovich and Ed Bodmer discuss the economics and finances of nuclear power and hydrogen cogeneration.
Above: EDF is planning to install an up to 2 MW electrolyser at the Sizewell site, which can use the electricity from Sizewell B to generate hydrogen for construction site traffic (Photo credit: EDF Energy)
With the use of new ENERGY SOURCES and advanced technologies, there is a continuous development in energy supply, demand and distribution. But most of the energy infrastructure around the world exhibits great “inertia” – that is, it takes years or decades to replace it – and long-term developments will affect the energy industry in decades to come.
Nuclear power plants are also evolving and making technological advances to make them more versatile. Modern nuclear power plants will function as part of an electricity system very different from that which existed when the nuclear power plants currently in use were built.
Another technology that is making technological advances to become more versatile is hydrogen cogeneration, and as the energy industry advances, hydrogen production is gaining visibility and political support around the world.
As markets rapidly integrate renewable energy sources, including wind and solar, it becomes more difficult to maintain the balance between supply and demand. Energy requirements vary over the course of the day, dropping briefly in the morning and peaking in the early evening when people come home from work. Nuclear power plants usually run at full load, but are theoretically still able to achieve greater operational flexibility. It is the operational flexibility that enables nuclear power plants to react dynamically to seasonal shifts in demand or hourly market price changes.
In practice, more promising nuclear power applications, including hydrogen generation and high temperature process heat, have recently been added to the International Atomic Energy Agency’s program. In 2018 it said: “The OECD Nuclear Energy Agency, Euratom and the Generation IV International Forum have all expressed an interest in non-electric nuclear power applications that focus on advanced and revolutionary next-generation nuclear reactors”. According to Ibrahim Khamis from the IAEA, among other things, the improvement of profitability, meeting the demand for energy-intensive non-electrical goods, securing the energy supply of industrial complexes, adapting to seasonal fluctuations in electricity demand and adapting small and medium-sized electricity networks with accessible large networks.
Advantages of nuclear power and hydrogen cogeneration
Every year around 50 million tons of hydrogen are used worldwide. Nuclear power plants and hydrogen generation systems are well coordinated in order to give nuclear energy an economic advantage over conventional energy sources for hydrogen generation. Nuclear power plants can provide the heat and electricity they need without causing CO2 emissions. The generation of hydrogen should serve as an energy store and decouple electricity production from electricity consumption. The stored hydrogen can either be used as fuel for combustion-based generators or sold for other industrial purposes.
Hydrogen production was also viewed as an energy storage technology in a 2017 study (Coleman, Bragg-Sitton, & Dufek, 2017). MIT Energy Initiative (MITEI) researcher Jesse Jenkins and colleagues at Argonne National Laboratory considered combining renewable resources with flexible nuclear power plants. In a paper for Applied Energy, Jenkins claims it makes more sense to run a lower powered nuclear power plant and absorb as much free wind and sun as possible. In this way, nuclear power works flexibly to integrate renewable energies and reduce carbon dioxide emissions. Flexible operations improve revenues from reactor ownership by reducing the amount of waste fuel, improving system quality, and lowering customers’ energy costs.
The development of energy storage systems for hydrogen could reduce emissions from power generation compared to emissions from burning fossil fuels, according to a paper published in the journal Sustainability (Noussan, Raimondi, Scita & Hafner, 2021). They say integrating fuel cells with hydrogen in the transportation sector and using energy storage to reduce peak power generation will reduce CO2 emissions, provided that the only by-product of hydrogen combustion is water.
However, the emission of carbon from the life cycle of the hydrogen fuel cell depends on the primary energy source and the process used to generate hydrogen. The use of water in hydrogen production can also have a significant environmental impact. However, when the hydrogen is recombined with oxygen in a fuel cell to generate electricity, water is produced and can be returned to the original source.
When producing hydrogen, toxic metals such as palladium are used for the electrodes and catalysts. Therefore, the disposal of used fuel cells is another aspect that must be carefully monitored in order to reduce the negative impact on the environment. Recently, research has focused on the recycling and reprocessing of palladium with the aim of reducing its negative environmental impact.
If nuclear energy is viewed as the primary energy source for hydrogen production, it should cause minimal emissions and have minimal impact on the environment.
A US public-private project aims to demonstrate HTSE with heat and power, likely at the Prairie Island nuclear power plant (Image rights: Xcel Energy)
Challenges of nuclear power and hydrogen cogeneration
Nuclear cogeneration is facing major challenges, including differences between the nuclear and heating markets. There are also specific questions and concerns related to nuclear power plants whose design has been changed to make it more suitable for hydrogen production (mining, planning time, construction and financial risk), industry-specific nuclear power plant demonstration, and custom nuclear unit licensing.
Nuclear power generation is feasible and economically viable; However, any nuclear reactor is subject to a number of operational restrictions arising from nuclear reactor physics, and these are different from the technological limitations of traditional coal or gas-fired power plants. For example, if the minimum stable performance of a nuclear reactor changes during the fuel irradiation cycle, production cannot be ramped up or down too quickly without stressing the nuclear fuel rods and the reactor itself.
At high outputs, excess energy is available, the reduction of which is viewed as largely unfavorable for the system. The energy surplus would suffer if the plant were operated flexibly to accommodate demand management.
Conclusion
The potential advantages of nuclear hydrogen over other sources are significant and could lead to a growing proportion of hydrogen production in a future global energy economy. However, nuclear hydrogen processes are technically unsafe and require extensive research and strong development efforts. Safety issues and the storage and delivery of hydrogen are critical areas for development to promote a prosperous hydrogen economy.
When evaluating the cost of green hydrogen, that is, that produced by electrolysis of water with low carbon electricity (the likely alternative, making methane from methane with steam reforming and carbon capture, is called ‘blue’ hydrogen), the analysis needs to consider cost and efficiency of an electrolyzer and the replacement of its stacks, the compression and storage of hydrogen, the cost of hydrogen transport, and finally the efficiency of hydrogen delivery.
One of the ultimate questions about the future of hydrogen in a decarbonized world is the cost of producing hydrogen from an electrolyser versus alternative means of providing hydrogen for transportation, fertilizers, industrial uses, and other things.
Accurately calculating the cost of hydrogen as a lifetime cost allows you to address various business models, e.g. You can also compare the cost of hydrogen from an electrolyser to the cost of hydrogen from a steam methane reactor; Assess the costs and benefits of distributed hydrogen production versus centralized production; and measure the effectiveness of a strategy that produces hydrogen during times of low electricity costs.
Authors: Paul Lalovich, Organizational Effectiveness Advisor, Agile Dynamics; Ed Bodmer, Organizational Effectiveness Advisor, Agile Dynamics
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