Siemens Gamesa has installed the first 11MW turbine at sea in a milestone that also marked the debut deployment at a subsidy-free offshore wind farm.

Installation of the manufacturer's SG11.0-200DD at the Vattenfall-led 1.5GW Hollandse Kust South project in Dutch waters represents another ramp-up in power for the offshore wind sector as its turbines push above 10MW towards the 14MW and 15MW models that will roll off production lines within the next few years.

The installation is also the first turbine in the water at a subsidy-free project, as Vattenfall and co-investors BASF and Allianz will run the wind farm with no support from the Dutch government.

The €3bn ($3.4bn) Hollandse Kust South is due in operation in 2023 when it will become the world’s largest offshore wind farm in service before being overtaken by other North Sea projects later in the decade.