Concluding a two-year series of lectures on the energy transition, this colloquium aims to shed further light on this perspective through, on the one hand, discussion of topical political and economic issues that cannot be ignored and, on the other, promotion of recent innovations by young French companies. The key issues are energy sovereignty and the role of the state, European energy policy and the energy market. The innovations concern fields of great importance for the development of a new energy and environmental model, such as the depollution of plastics, the recovery of biomass, waste and carbon dioxide, and the " verte " production of hydrogen.