The main problem with using renewable energy sources is that they are not as reliable or consistent as traditional sources. This is especially true of wind energy, since wind turbines work at generating power until the wind is blowing, but stop once the wind stops. Because of this, even areas that get a lot of wind can’t transfer solely to wind power. Furthermore, wind turbines have a cap as to the maximum speed at which they can rotate and generate power, which is in place to prevent the machine from getting damaged in high winds. However, this also leads to “spillage” of power.
An electrical engineering doctoral student at the University of Nebraska-Lincoln Jie Cheng recently came up with a new technology, which would solve both of these problems. The tech he proposes is able to harness the excess wind energy, which is wasted as spillage. The system he developed is also able to store this excess wind energy to be used in times of little or no wind.
Cheng’s device works by converting and directing the unused wind energy into an air compression tank. This is achieved via a rotary vane, placed between the turbine’s gearbox and generator, which works to divert the excess energy and stores it in the tank. Once the winds die down, the airflow is reversed back to the rotary vane and the machine is able to generate electricity again.
According to tests with a prototype, a 250-kW system built in this way would produce an additional 16,400 kWh per month compared to traditional wind turbines and using the wind data for Springview, Nebraska. To put in in perspective, this additional electricity is roughly 18 times the total monthly energy usage of a typical US household.
Cheng is currently working with the Lincoln Electric System, the American Public Power Association and UNL’s NUtech Ventures office in an effort to continue to research an develop this technology, as well as to market it to the industry.