Nacelle lidar for power curve measurement - Avedøre campaign

Wind turbine power performance requires the measurement of the free wind speed at hub height upstream of the turbine. For modern multi-megawatt wind turbines, this means that the wind speed needs to be measured at great heights, from 80m to 150m. The standard wind speed measurement with a cup anemometer, requiring the erection of a tall met mast, then becomes more and more challenging and expensive. A forward looking lidar, mounted on the turbine nacelle, combines the advantages of a nacelle based instrument - no mast/platform installation difficulties - and those of the lidar technology - remote measurement of the wind speed away from the instrument.
In the first phase of the EUDP project: “Nacelle lidar for power performance measurement”, a measurement campaign with a na-celle lidar prototype placed on an onshore turbine demonstrated the poten-tial of the technology for power curve measurement. The main deviations of this method to the requirement of the IEC 61400-12-1 were identified and a procedure was established for the use of a nacelle lidar specifically for power curve measurement. This report describes the results of a sec-ond measurement campaign aiming at testing and finalising the procedure.