[en] This huge document comprises several reports, and first proposes an executive summary which gives a synthetic overview of the present status of wind energy in France and abroad, of an assessment of 15 years of a policy of support to wind energy, of perspectives of development on the medium term, of economic spin-off on the long term, and of the ADEME's role in a national strategy for wind energy. These issues are then addressed in a more detailed way with notably a presentation of complete wind energy costs in France, a synthesis of an international benchmark, a detailed analysis of the support policy (in terms of efficiency, usefulness, costs-benefits), a characterisation of market evolutions, a discussion of constraint evolutions and of development strategies. A synthetic version of this report is then provided. More detailed reports are proposed on the various issues: first, analysis of the chain value, status of the sector in France and international benchmark; secondly, an assessment of the support policy through an assessment, a prospective and strategy, and then a detailed discussion of macro-economic spin-off and of jobs in the sector on the long term in association with wind energy development. A third part proposes a presentation of ADEME's strategy and action plan in favour of wind energy. Finally, a set of appendices contains presentations of survey questionnaires and of survey result processing, presentations of results regarding actors and countries, and presentation of modelling methodologies