Hydrogen is the most abundant chemical element in the universe. It is colourless, odourless, and nontoxic, an essential element for life on earth. A hydrogen molecule – H2 – is often called an “energy carrier” as it is produced from other energy sources. And unlike electricity, hydrogen can be stored in large quantities. It is also a clean-burning fuel, and when combined with oxygen in a fuel cell, hydrogen produces heat and electricity, with only water vapour as a by-product. It is also compatible with combustion turbines and reciprocating engines to produce power with near-zero emission of pollutants. Therefore, hydrogen could play a significant role in energy systems and serve all sectors of the economy, substituting for fossil fuels and helping mitigate global warming.
For hydrogen to fulfill its enormous decarbonization potential, its production must also account for the environmental impact of its energy sources. Today, most hydrogen is produced through steam methane reforming or coal gasification, which results in considerable unfavourable emissions. Therefore, a parallel pathway for hydrogen production from zero-carbon sources is through water electrolysis – where electricity is used to decompose water into oxygen and hydrogen gas.
Nuclear technologies are evolving and undergoing technological advances and are therefore well positioned to overcome today’s challenges with making hydrogen gas. Aside from generating clean electricity, nuclear plants can also produce high heat that can be paired with a more efficient high-temperature steam electrolyzer (HTSE). Hydrogen can be produced via electrolysis using off-peak nuclear electricity, and high-temperature thermal processes or coupling with small modular reactors are viable. Advanced reactors that operate at very high temperatures can produce hydrogen thermochemically without the use of electrolyzers. The unique characteristics of nuclear energy allow it to pair with these low-cost, high-efficiency production processes, facilitating nuclear hydrogen production’s economic competitiveness.
Recognizing the value that nuclear energy can bring to hydrogen production, many endeavours and pilot projects have emerged to pave the way for large-scale nuclear hydrogen production. These initiatives are included in national hydrogen visions, plans, and strategies, as in Canada, the United Kingdom, and the United States.