Turby wind turbine
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The Turby is a brand of vertical axis Darrieus wind turbine. The three vertical aerofoil blades have a helical twist of 60 degrees, similar to Gorlov's water turbines [1]. Since the wind pulls each blade around on both the windward and leeward sides of the turbine, this feature spreads the torque evenly over the entire revolution, thus preventing the destructive pulsations of the straight-bladed giromill. Starting is achieved by operating the generator as a motor.
Another advantage of the helical twist is that the blades generate torque well from upward-slanting airflow. This is negligible in open country, but tall buildings and cliff faces generate a bow wave which directs airflow up and over them. Turbines mounted on building rooftops or clifftops are exposed to significantly slanting flow, and the Turby can extract more useful energy from it than a propeller-type turbine can.
The turbine measures 2.0m in diameter by 2.9m high (including generator), and weighs 136kg. It is specified to generate in winds of between 4m/s and 14m/s, and can survive winds of 55m/s. Rated power at 14m/s is 2.5kW. The AC output from the synchronous generator is rectified to DC, then inverted to AC at 230V 50Hz.
The turbine was developed in the Netherlands with research input from the Delft University of Technology.
[edit] External References
- Turby b.v.
- A quiet revolution - wind energy for town and country - Story about Turby