[en] Is France ashamed of its tidal energy? It's a valid question in view of the ambivalent attitude to a form of energy that is completely renewable, predictable and abundant. We are proud to acknowledge the pioneering industrial success of the Rance plant, but perplexed and sometimes even hostile to the popular belief that no new sites can be envisaged. This ambivalent perception has even been set down in the national vision: the report of the inter-ministerial audit on renewable marine energies published in March 2013 recognizes its technological maturity and its potential. However, the questions of environmental and societal acceptability are highlighted as a major disincentive for considering it as a future option. The SHF is convinced that this energy has a future. In 2015, re-engaging with its initial missions, the Societe Hydrotechnique de France (SHF) decided to set up a working group called 'New tidal energy' to take another look at the fundamentals of this powerful source of energy and redefine modern and responsible conditions for its development. Bringing together more than twenty experts and specialists, it offered thoughts, data and proposals for actions to re-open the tidal option, a mature technology with great potential for innovation. This working group highlighted the conditions for the feasibility and viability of new projects in a modern and innovative approach, without any concessions on the questions of their environmental integration. The goal of this report and booklet is to put tidal energy back into a framework that has evolved considerably since the commissioning of La Rance plant. It offers a summary of our work, setting out our convictions and the keys to the success of future projects: global territorial integration, optimised environmental integration, innovation to drive development and a lucid, transparent economic assessment. On the basis of this work, the SHF is convinced that tidal energy is a major asset for the energy transition, to enrich the mix of low-carbon energy sources. The French territories are amongst the first committed to implementing this transition in the field and we believe that tidal energy is an asset for economic, social and ecological development.