PV modules drive an electric motor keyed on the wind turbine shaft until it is brought up to a minimum rotational speed value such that it can then operate autonomously.
The surplus energy produced by the PV system and not used for turbine operation is fed into the grid along with that produced by the wind turbine. To ensure machine startup even under extreme conditions (no light), an energy storage system is provided.
Integrating the PV system with the wind turbine increases the annual energy production of the turbine with the same performance.