[en] A first document (of 5) reports the development of scenarios of deployment of hydrogen hubs with storage in three French regions (Auvergne-Rhone-Alpes, Grand Est, PACA). This comprises needs in storage and assessments of demand and supply in renewable and low carbon hydrogen, identification of the origin of hydrogen supply, assessments of average production costs, of job creations, of avoided greenhouse gas emissions. The second document analyses current dynamics, and potentials and benefits on the short and medium terms, outlines that the development of hydrogen hubs and the territory dynamics is a virtuous circle, identifies the main stakeholders, outlines the high potential of the three regions for the development of hydrogen hubs with massive underground storage, identifies stakes by 2030 used to develop scenarios (mobility decarbonization, industry decarbonization, new industrial sectors, network infrastructures). Scenarios with massive storage are then presented, notably in terms of decarbonized hydrogen demand and supply, and in investments. Economic spin-offs and the contribution to energy transition are outlined. Similar documents associated with the different regions are then proposed for each region