To achieve the target of 10 million tonnes of renewable hydrogen production in the European Union (EU) by 2030, the REPowerEU Plan commits the EU to double the number of hydrogen ‘valleys’, which will contribute to accelerating the production of renewable hydrogen to replace natural gas, coal and oil in hard-to-decarbonise economic sectors. This article reviews ongoing efforts to lay down a regulatory framework to move from natural gas to renewable hydrogen and, not least, to define renewable hydrogen. As a strategic net-zero industry, renewable hydrogen is to grow and flourish in hydrogen valleys, meaning a place where energy production and multiple-uses will meet and expand. This requires substantial EU financial support, at least until renewable hydrogen becomes a mature technology that can compete in the market with today's cheaper (and polluting) fossil-based hydrogen. While there are open questions about the pace and viability of hydrogen-related technologies and infrastructure, for instance concerning long-distance transportation, hydrogen valleys appear as a no-regret option encompassing renewable energy production, repurposed gas infrastructure, electricity grid and batteries. If successfully implemented, the option would enhance renewable hydrogen production and the decarbonisation of the industry and transport.