Wind project developers in the US through May have proposed turbine heights up to a record 207 metres (680 feet) versus an average 146 meters for 2018 installations, as the industry benefits from technology advances, according to a new Department of Energy (DOE) report.

Permit applications filed with the Federal Aviation Administration (FAA) this year show 44% of proposed turbines will exceed 152.4 meters in height (from ground to blade tip extended directly overhead), up from 39% in 2018 and 14% in 2017. The FAA regulates all aspects of civilian aviation.

From 2022 through 2016, less than 5% of permit applications included turbines with a total height over 152.3 meters, the so-called “soft cap” that can trigger a public comment period. That is now less of a concern – although each project is different – with greater acceptance of taller turbines at the community and regulatory levels.

Lawrence Berkeley National Laboratory scientists Mark Bolinger and Ryan Wiser, primary authors of the 2018 Wind Technologies Market Report, noted the FAA data represents total turbine height, not hub height, and therefore includes the combined effect of both tower and rotor size.

The tallest proposed turbines would be located almost exclusively in the Great Lakes region while most others proposed between 152.4 meters and 201 meters in height are targeted for the country’s blustery interior.

In 2018, turbine size continued to increase in response to technology advances as developers grow more comfortable with larger, taller machines that optimise project cost and performance.

Both rotor diameters and hub heights increased in 2018, continuing the long-term trend, according to the report.

Rotor scaling has been especially significant in recent years with 30% of the 3,123 turbines installed last year having rotors greater than or equal to 120 meters. The average rotor diameter was 115.6 meters, up 2% over 2017.

Wind

US developers propose record 207-metre wind turbine height