Hydrogen is expected to play a central role in achieving climate change goals while helping to secure supplies of reliable clean energy worldwide. But with almost all hydrogen currently generated using fossil fuels, shifting to clean production by nuclear power and renewables is urgently needed. That is a challenging prospect, requiring the creation of a new industrial base and supply chains. Currently, hydrogen is used in industrial processes ranging from producing synthetic fuels and petrochemicals to manufacturing semiconductors and powering fuel cell electric vehicles. In order to decrease the environmental impact of the annual production of over 70 million tonnes of hydrogen, some countries are looking to renewables such as solar and wind as well as nuclear power as a replacement for fossil fuels.To speed up greening of the emerging hydrogen economy, the IAEA last month launched an initiative to develop a roadmap for the commercial deployment of hydrogen production using nuclear energy. The initiative brings together decision makers, designers, project managers and operators to share the latest advances in national strategies and technologies and to identify technical readiness for different technologies of hydrogen production using nuclear energy. The initiative will culminate in a roadmap guiding document, to provide countries with a tool for evaluating, planning and strategizing the development of nuclear hydrogen projects.Producing clean hydrogen using nuclear power has historically faced cost barriers, but that is now changing amid a global energy crisis making fossil fuels significantly more expensive and their global supply less secure. A recent IAEA FRAMES modelling analysis found that when natural gas prices rise above USD 20 per million British thermal units, the optimal method of hydrogen production is electrolysis powered by a mix of nuclear and renewables.The analysis also found that hydrogen production powered by heat from advanced technologies such as high temperature gas cooled reactors was highly competitive in those price scenarios. HTGRs are under development in several countries and prototypes are already operating in China and JapanInterest in clean hydrogen is growing across the world, with specific interest in using nuclear power. Some 28 countries and four international organizations joined the IAEA roadmap initiative at its launch in Vienna last month to discuss their nuclear hydrogen plans or projects. These include demonstrations of hydrogen production using existing reactors as well as plans using advanced reactors such as small modular reactors to increase efficiency and allow for scaling up production.In India, the government this year announced a commercial hydrogen roadmap with a focus on renewable and biomass derived hydrogen. But since the demand for hydrogen is expected to rise fivefold by the mid-2030s, studies and research are being carried out to develop a business case to include nuclear in the country’s system for producing low carbon hydrogen.