Bird Safe Turbine produces Double the Energy of Today’s Best
World Wide Wind, a Norwegian company, has developed an innovative system that is essentially two vertical-axis wind turbines (VAWTs) in one. The Contra-Rotating Vertical Turbine (CRVT) is a hybrid vertical-axis wind turbine, which means that its two sets of blades spin in opposite directions. It features one turbine at the top and another at the bottom of the machine. The machine’s rotors are connected to the stator, doubling the rotation speed.
This system combines two concepts commonly associated with enhanced power production: a magnetic hysteresis brake and a contra-rotating propeller. The contra-rotating propeller cancels out the asymmetric torque effects associated with conventional propellers, resulting in high performance and low induced energy loss.
The CRVT has a lower center of gravity, which makes it more stable in the offshore environment. This lower center of gravity also allows for a lower turbine height and translates to a lower manufacturing and installation cost. In addition, the turbine’s blades can be made from recycled materials further increasing sustainability. The company’s CRVT turbines are estimated to achieve a Levelized Cost of Energy (LCoE) below $50/MWh, which is about half the cost of a conventional turbine.
This technology also has the potential to lower the production cost of offshore wind power just based on the amount it produced. Real-world tests showed that the contra-rotating turbine could produce twice as much power as a single turbine of the same height. Floating vertical-axis wind turbines have been tested in typhoons.
Unlike traditional wind turbines, the blades are quiet and specially designed to reduce the turbulent wake downstream from the towers. Because of their lower height and easy-to-see silhouette, they are easily avoided by migratory birds.