Wind turbines installed in the US in 2019 were larger, taller and more productive than ever before, driven by advancements in technology, improved siting techniques and more public acceptance as the country transitions to cleaner energy sources, according to an annual report by the American Wind Energy Association (AWEA).

The average nameplate capacity rating of turbines set turning last year was 2.55MW, up 5% from 2018 and 27% when compared 2015, as the US fleet grew by 9.14GW. All new capacity was onshore.

GE Renewable Energy’s 2.5-127 was easily the most popular model built, with 2.1GW installated country-wide, then Vestas’ V136-3.6 (1.03GW) and the GE’ 2.3-116 (775MW), according to Wind Powers America Annual Report 2019.

While more 2MW wind turbines were installed than any other nameplate rating their 1.5GW total capacity was down from about 1.8GW in 2018. Vestas dominated this market segment with its V110-2.0 and V116-2.0 models.

Even so, most GE and Siemens Gamesa, all Nordex, and an increasing number of Vestas turbines installed last year were 2.5MWs or bigger, while the share of 3MW-plus machines deployed continued to grow, capturing 25% of the market in 2019 versus 18% in 2018 and 14% in 2017.

Vestas won most of the 3MW and above market with 1.3GW installed but faces growing competition from Nordex and Siemens Gamesa. GE also has ambitions there installing its first 3.6-137 models.

The 3MW platform market centres on Texas, midwestern states of Illinois, Indiana, Iowa, Michigan, Minnesota, Missouri and Wisconsin, and the Plains states of Kansas, Nebraska, North Dakota, Oklahoma and South Dakota.

The average rotor diameter of a turbine installed in 2019 was 121 metres, up from 116 metres a year earlier, and 96% of all turbines had rotor diametres of at least 110 metres in length, according to the report.

The share of nationwide turbine capacity installed with rotors at least 120 metres in diameter jumped from 14% in 2017 to 30% in 2018 to 60% in 2019.

Power captured by a turbine is generally proportional to the swept area of the blades, meaning increased rotor diameters allow projects to be sited at lower wind resource areas, yet still produce a competitive, levelised cost of energy. Larger rotors also enable turbines to enhance energy output in wind-rich regions.

Hub heights increased slightlly in 2019 to 90 metres from 88 metres the previous year, as projects owners look to access steadier wind speed profiles. With more constant wind speeds at higher altitudes, energy production increases even when using the same turbine rating and rotor diameter.

Meanwhile, tower heights continue to soar. In 2019, 37% of project applications with the Federal Aviation Administration (FAA) were for tower heights over 152.4 metres (500 feet), versus 31% in 2018 and 15% in 2017. More than 3,860 turbines were proposed with a total height of 182.8 metres last year.

Alta Wind set a US record when installed GE 3.6-137 turbines at its Big Level project in Pennsylvania stood at 199.5 metres (654.5 feet) from the base to the tip of the blade.

Meanwhile, turbine specific power ratings continued to decline last year to 220 W/m2, which helped them to increase capacity factors and produce more energy per nameplate capacity.

GE retained its leading share of the US wind market in 2019 with 45.4%, or 4.14GW, installing 1,679 turbines mainly in Texas, the Midwest and Plains states. Vestas was second with 32.9%, or 3GW, placing in service 1,206 turbines, the great majority in those same regions.

Siemens Gamesa took 15.6%, or 1.42GW, installing 520 turbines. Nordex was in fourth place with 6%, or 549MW, placing 168 turbines in service. Other vendors had a minimal presence with 15MW installed.