Vestas has posted a video on its social media channels of its 900kW four-rotor concept in motion at the test site in southern Denmark.
First power from the prototype turbine was produced in July, Vestas said, as it undergoes testing and validation.
According to Vestas, the design has been verified by TUV SUD.
The turbine, unveiled exclusively by Windpower Monthly in April, comprises four V29-225kW turbines attached to a central tower.
It features two nacelle operational levels with a cylindrical tower section between and 30.5-metre height interspacing between the levels. The structure's tip height reaches 74 metres.
The nacelles are mounted separately on left and right side tubular-steel arms. These arms in turn are flexibly attached to a rotating central chassis.
The concept is being tested in three perspectives — aerodynamics, structure and load.