Reducing greenhouse gas emissions and addressing the gradual disappearance of fossil fuels figure among the challenges the planet must face in the years to come. Hydrogen can and indeed must play an important role in the energy transition. Since the technologies that allow for the safe production and use of hydrogen are now mature, this carbon-free molecule can enable the shift to a “clean” world.Hydrogen has the capacity to store primary energy, particularly renewable energies. Combined with a fuel cell battery, it can also make this energy available in the form of electricity in a large number of applications, starting with those that pertain to mobility. But while the technical difficulties are in the process of being resolved today, responses to the economic and financial challenges have yet to be found: going forward, it will be necessary to structure large-scale industrial and commercial deployments. And doing so will require new forms of global cooperation between the private sector and public policymakers at the international level. In a word, launching the energy transition requires a paradigm shift.