Jie Cheng, an electrical engineering doctoral student at the University of Nebraska-Lincoln, has developed a new technology which stores excess wind turbine energy and releases it to drive the turbine when winds drop.

The system stores the extra wind energy in an air compression tank connected to the turbine. Using a rotary vane machine that is connected between the turbine’s gearbox and generator, excess energy is diverted and stored in the air compression tank. When the wind dies down, the airflow is reversed back to the rotary vane machine to generate electricity.

A prototype 250 kilowatt system produced an additional 3,830 kilowatt-hours of electricity a week. The technology has the potential to cut the cost of electricity while significantly reducing fluctuations in power supply.