Vattenfall's Nij-Hiddum Houw wind farm in Súdwest-Fryslân, Netherlands has produced green electricity for the first time.
The first of the nine turbines is ready and will be tested in the coming period, the developer said.
The power generated during this phase immediately ends up on the electricity grid.
The wind turbines are already producing energy, but not yet at full capacity.
During the test phase, it is slowly scaled up to full production.
The green electricity generated by the wind turbines during the test run is supplied directly to the electricity grid.
Project leader Willem van Dongen said: "This is an important moment for the project and for us as an energy company that wants to make a fossil-free life possible.
"This is what we ultimately do it for: the years of preparation, it is all intended to be able to produce sustainable electricity.
"In the coming weeks, we will continue with the construction and installation of the remaining wind turbines and we expect all nine wind turbines to be fully operational by the end of this year."