Winds power load balancing: Ultracapacitors help
Wind power is increasing as traditional energy markets are influenced by regional instabilities and, with recent events in Japan, nuclear power seems less attractive politically in many areas. The wind turbine market also is taking advantage of rapid technology advances. [See article on direct-drive wind turbines.] Manufacturers once struggled to cost-effectively capture consistent wind-generated power, but a shift in energy storage practices has resolved that problem. Ultracapacitors are replacing battery-driven energy storage systems and introducing new efficiencies in the wind turbine market, helping to balance the electricity grid.
While the rotor blades of a turbine can be adjusted to respond to current conditions, this changeability creates waste in battery-powered systems, which are sized to meet the highest possible power demands. Batteries also struggle under moments of high peak power and perform poorly in low temperatures. With short life spans, batteries force maintenance crews to frequently swap out components under potentially dangerous conditions.
Ultracapacitors resolve those problems because they:
Have a long life span. Batteries last 2 to 4 years, but ultracapacitor life span is more than 10 years.
Can withstand extreme temperatures. They operate optimally at a temperature range between -40 C and 65 C, whereas batteries function best at -20 C to 40 C.
Have impressive cycling capability. A battery can offer only 10,000 to 50,000 cycles compared to an ultracap’s million-plus.
Are dropping in cost. The cost of ultracaps has decreased by 99% in the last 10 years. During the same period of time, battery price fell by only 30% to 40%.
For the above reasons, new wind turbine installations will favor ultracapacitors to control blade pitch, ensure optimum positioning, and capture wind speed for better performance and safety.
– Posted by Chris Vavra, Control Engineering, www.controleng.com