Alstom installed the 6MW prototype at the Belwin 2 wind farm in October last year making it the first of the model to be put in place offshore. But had been waiting for a grid connection since.
That 1.8-kilometre, 33kV connection was installed in the middle of August. However, the turbine is yet to export its first power.
Alstom said it expects the turbine to start generating power by the end of September following "ongoing tests" at the site that should last three weeks.
Alstom has won a number of contracts to supply the turbine on a commercial scale. The company won the tender to supply the turbines for French offshore projects, the 480MW Saint Nazaire, 450MW Courseulles-sur-Mer and 498MW Fécamp.
Alstom is also lined up to install five of the turbines at the Block Island project in the US, some of which were transported to the new factory at Saint Nazaire in the north west of France last week.