The project started in 2014 with a plan for an off-shore park of 60 to 80 windmills in an area of 120km2, at 15km of the port of la Cotinière, for a total power of 500MW. The park was supposed to bring electricity to 650 000 inhabitants, meaning the whole population of Charente maritime, and create 400 to 600 local jobs for the construction, 100 for longer term maintenantce. Its cost was estimated to two billion euros and the plan was for the windmills to start operating in 2023. After a cartographic work and concertation meeting to identidy the area, the project is validated. The German company WPD Offshore won the call for tenders. 
However, five associations opposed the project for its size and its implantation in the marine natural park of the Gironde Estuary and the Pertuis Sea and "Natura 2000" area, thus its impact on migratory birds, bats, turtles etc.  The project was also not welcomed by local fishers, who would see their fishing area impacted.  Moreover, the Agency for Marine Areas gave an unfavorable opinion, arguing that it would "contradict France's engagements regarding the "Birds directive" (part of Natura 2000 area).
In 2019, the project was brought back to the forefront: the Minister of Ecological Transition François de Rugy declared a call for tenders would be launched for the Oléron offshore wind project.  In 2021, the National Council for the Protection of Nature released a report, agreeing with the Agency for Marine Areas: it stated that the project "should absolutely avoid Natura 2000 areas, and notably the "Birds zones", which are the richest in biodiversity (...) or else the project will be weakened from a legal point of view." 
In january 2021, the government announced the launching of the project. This surprisingly happened at the same time as a communication campaign on renforcing biodiversity protection's politics in France, with the opportunity to write it in the Constitution. In parallel to the announcement, the National Comission for Public Debate (CNDP) was launched. 
It is clear from the document of the CNDP that the public debate is not about wether the project should be done at all or not. However, according to the Code of the Environment regarding the work of the CNDP, this question of wether or not doing the project at all should be debated.  A few paragraphs are written about the possible costs if the project was not to happen, but that's it. On the contrary, the document is only about the location of the project, in a pre-established zone, and its possible extension to a second park.  Indeed, while the CNDP was at first asked to regard one park of 320km2 with a power between 500 and 1000MW, when the public debate opened in September, the State proposed a second park, of a power of 1000MW, and a total surface of 743km2.  This extension consolidated even more the local opposition to the project: it did not look at all like the "local" project of 2014 anymore, especially in the Charente Maritime already "invaded" by dozens of windmills on land.  Also, for the fishers, the pre-established area would be the worst place, as it under 20 miles near the coast (37km), in the zone where less than 12m long boats can fish, which represent the majority of the local fleet. They also did not believe in the possibility of fishing inside the windmills park. 
The CNDP named a Special Commission for public debate (CPDP) to organize the debate. Leaded by Francis Beaucire and composed of five members, the Commission is meant to be neutral and independant. It should be noted that the two unfavorable reports from the ex-Agency for Marine Areas (2015) and the the National Council for the Protection of Nature (2021) were not added to the resources for the public debate. They were brought up by environmental associations several times and ended up being added to the public debate website only two weeks before the end of the process. 
During the public debate, the Commission could testify of the total absence of consensus on the project, and the pertinence of the question wether is should be pursuid or not. Some alternatives were also brought up by participants, and the Commission asked some experts to explore the possibility. One of the final recommendations of the Commission to the State and the RTE was to envisage a wind farm outside the natural marine park and the coastal fishing zone.  To read more details about the debate and the alternatives, please refer yourself to the "Proposal and development of alternatives" section in "Outcome".
Following the report of the Commission in april 2022, the State announced in july that there will be a first and then a second call for tenders for the installation of two wind farms of about 1,000 MW each off the island of Oléron. It has also revised its position on their location, and the nearest one to Oléron will be 40 kms distant, outside the natural park and coastal fishery zones. 
However, this remains insufficiant for the fishers, environmental organizations and some local representatives. Some call for a zone even further the coast, up to 60 or 70kms away. Some environmental studies are still needed to completely define the construction zone of the projet, which is planned for 2030.