According to the tender terms, Ailes Marines should have submitted its application to occupy the maritime domain and seek authorisation under environmental law on 23 October this year.
The deadline will be delayed to 23 October 2015, conditional on the environment minister approving the turbine upgrade.
Ailes Marines will now be able to carry out further technical and environmental studies in order to adapt the project to the 8MW turbine. The project was originally set to use Areva's 5MW machine.
The consortium still plans to have the project fully operational by 2020.
Areva, which is working with Gamesa on a prototype 8MW, expects to install the machine in late 2015 or early 2016 at a site yet to be announced.