Spinner anemometry - an innovative wind measurement concept

For a wind turbine it is extremely important to know the wind speed and the wind direction to make control corrections.

 
A wind turbine looses power and the loads are increased if the wind is not coming perpendicularly into the rotor. Today it is a problem because the sensors, that measure wind speed and wind direction, are positioned on the back of the nacelle, where the wind is severely distorted by the blades and the nacelle itself. The blade sections change directly the direction of the flow, and the blade root section produces large vortices which sweep over the back of the nacelle and disturb the wind measurements. The result is that wind turbines today looses power and have increased loads, which may be optimized by improved measurements of the wind as seen by the wind turbine.


A spinner anemometer is a new concept that measures the wind speed and wind direction very accurately as seen by the wind turbine. A spinner anemometer utilizes the flow over the spinner of the wind turbine. The spinner is the aerodynamically shaped cover over the hub of the wind turbine, which is mounted mostly for aesthetic reasons. The spinner anemometer converts the spinner into an integrated part of the horizontal wind turbine concept.

A prototype spinner anemometer has been tested in cooperation with Siemens Wind Power. Siemens have provided a spinner for a 300kW wind turbine and the spinner anemometer has been tested in a large wind tunnel. This spinner anemometer has also been tested in the field and been compared to a three dimensional sonic anemometer with very promising results. The concept is now tested on a full scale 3,6MW wind turbine at Høvsøre test site. The results have been presented on a poster at the European wind energy conference at Milan May 2007. The presentation won an award for the most innovative concept.

For further information two papers are available:
EWEC2007 conference: Spinner anemometry - an innovative wind measurement concept
TWIND2007 conference: Aerodynamics and characteristics of a spinner anemometer

Page updated  12.01.2009


Troels Friis Pedersen
Professor
Wind Energy (VEA)
Dir tel+45 46775042