The launch comes at a crucial juncture for the maturing wind industry which is facing a battle to remain competitive while being weaned off generous state subsidies.

"It is necessary to take a significant leap forward with regards to industrialization," chief technology officer Anders Vedel told Reuters.

The turbine with its 138 meter rotor diameter has the industry's largest swept area, a crucial measure for how much energy can be harnessed, for a turbine with a tip height under 500 feet, which is often a requirement in the United States.

Vedel expects the annual energy production from the new turbine to be more than 30 percent higher compared to the older V120-2.2 MW turbine.

The new turbine, called V138-3.0 MW, is based on the EnVentus platform which Vestas presented this year and is built on a modular design to enable more customized turbines to be produced without expanding the number of components.

This technology is Vestas' attempt to move towards more scalable manufacturing to ensure that mass production of wind turbines remains commercially viable at a time of price pressure and rising demand.

Vestas, whose main rivals are Siemens Gamesa and General Electric, has looked at the auto industry's cost-saving modular platforms, Vedel said, referring to cooperation with Swedish truckmaker Scania.

The new V138 turbine can be used globally but is well suited for the U.S. market where many sites have capacity constraints with regards to how many megawatts can be installed and fed into the local grid.

Vestas said many of the same components from the two first turbines from the EnVentus platform had been used for the new one.

Vedel declined to say how much the new turbine would cost.

"The prices of turbines will always be decided by the market," he said.

(Reporting by Stine Jacobsen; Editing by Keith Weir)

By Stine Jacobsen