Bigger, more efficient wind turbines boost industry capacity

Source: Daniel Cusick, E&E reporter • Posted: Monday, March 17, 2014

The deployment of larger and more technologically advanced equipment has helped the wind energy industry boost generation rates on a per-turbine basis since 2008, resulting in greater operational efficiencies and lower costs for consumers, according to the American Wind Energy Association.
The data, culled from AWEA’s 2013 annual report, show that while U.S. wind energy capacity grew 140 percent — from 25,000 megawatts to more than 61,000 MW — over the last five years, the amount of electricity generated from those wind turbines grew by 200 percent.Much of the performance gain is attributable to the scaling up of wind turbine technology, according to AWEA, including increases in turbine blade length, rotor diameter and tower height. These three factors, combined with greater operational efficiencies, have allowed wind farms to produce more energy on a per-unit basis while at the same time allowing turbines to produce electricity in areas with lower average wind speeds.”Wind turbine and component manufacturers have been diligently working over the last few years to develop longer, lighter advanced technology blades that allow the systems to produce more energy at lower costs,” said Steve Lockard, president and CEO of TPI Composites, which produces advanced composite blades for GE Energy, Gamesa and other firms from its plants in Newton, Iowa, and Ciudad Juarez, Mexico.

The amount of power a wind turbine can generate is directly proportional to the swept area of the turbine’s blades. As such, an increase in rotor diameter or blade length will boost output from existing wind farms while also spurring new development in low- and medium-wind-speed areas, according to AWEA.

Tower heights have also grown steadily, allowing developers to access higher, steadier wind resources, AWEA said. A decade ago, the average wind turbine was installed on a 65-meter tower. Today, towers are routinely 80 meters in height, and some can go as high as 100 meters.

The industry has also made significant improvements to electronics and mechanical systems that help calibrate wind turbines to varying weather conditions and control their output.

For example, GE’s WindBOOST technology, which helps maintain mechanical and electric loading on GE’s 1.5 MW and 2.5 MW turbines, has increased average turbine output by as much as 4 percent, according to estimates released by GE last year.

Meanwhile, the Danish firm Vestas in late January rolled out its newest turbine prototype, the V164-8.0 MW model, the world’s largest turbine to date. The 8 MW turbine, to be used in offshore environments, claims a tower height of 140 meters and a blade sweep of 21,000 square meters.