As underlined by the EU`s Hydrogen Strategy for a Climate Neutral Europe and the REPowerEU programme, the development of a hydrogen economy is considered of strategic importance for the achievement of the EU Climate goals by both the EU and several of its Member States. As for any socio-technical transition, the development of the hydrogen economy requires careful policy and regulatory drafting, as well as the concrete implementation of projects affecting the living environment of people. Public participation is mandated under international, European and national law to ensure that the hydrogen economy best fits within the environmental and societal needs of the interested regions. This chapter uses the first fully fledged hydrogen valley in Europe as a case study to map the participatory requirements that should be applied in the development of a hydrogen economy and to show how these requirements have not been (fully) respected so far. In doing so, the chapter will provide data for comparative purposes and for the further development of the conceptual and applied frameworks for the hydrogen economy.