Green hydrogen could become the fuel of the future. It’s an attractive alternative to fossil fuels, because burning hydrogen yields only water, not carbon dioxide. Plus it’s a relatively renewable resource. But before that happens, we need the infrastructure to make green hydrogen in big scales, as well as innovative facilities to store it and use it efficiently. Hydrogen valleys are key locations that combine all these characteristics—connecting the manufacture, use, transformation and commercialisation of green hydrogen. We teamed up with the Green Hydrogen Valley in Catalunya to explain all this in a two-minute video, available in English and Spanish.