An estimated 60% of new wind turbines now employ electrical blade pitch systems that incorporate ultracapacitors or batteries for pitch control and backup power. Ultracapacitors offer burst power for control systems that enhance the consistency of wind turbines’ electrical energy output. The constant adjustment of the turbine blades compensates for changes in wind velocity and ensures that rotor speed remains within a safe operating range . Also, in the event of a main system power failure, ultracapacitors offer an independent source of backup power for orderly shutdown and smooth the flow of wind farms’ output to the electric utility grid.

Ultracapacitors have been incorporated into an increasing share of the electric pitch system market because of their longer operating lifetime, low maintenance requirements, and cold weather performance compared with batteries. Furthermore, manufacturer Maxwell Technologies states that the company’s Boostcap ultracapacitor products are functional at temperatures ranging from -40 to 65 C.