A collaborative research project at the Energy Department’s (DOE) National Renewable Energy Laboratory (NREL) has shown that the Wind Iris nacelle-mounted LIDAR from Avent Lidar Technology is an effective diagnostic tool for identifying wind turbine yaw misalignment.
The research project, supported by DOE, focused on the optimisation of turbine performance using forward-looking wind LIDAR measurements, with a focus on improvement of power output by correcting yaw misalignment and a reduction in turbine O&M costs through improved load mitigation. The research was conducted in collaboration with Avent Lidar Technology and Renewable NRG Systems. The study also validated the energy increase after yaw misalignment correction using the Wind Iris as an external reference sensor. The power curve improvement was measured and found to be nearly identical with wind speeds measured from the LIDAR and NREL’s reference meteorological tower. Based on the results, it is estimated that LIDAR-based yaw correction will increase the annual energy production (AEP) by 2.4% for a 7.5° static misalignment and standard reference wind speed distribution. NREL served as the overall project coordinator with the measurement campaign taking place at its National Wind Technology Center in Golden, Colorado. The LIDAR was installed on the two-bladed Controls Advanced Research Turbine (CART2). NREL performed data collection and analysis related to the use of LIDAR measurements. Avent provided its Wind Iris LIDAR for the project together and performed part of the scientific analysis related to LIDAR technology. Renewable NRG Systems was responsible for the coordination of the LIDAR field activities. Following the evaluation of static yaw misalignment correction, NREL, Avent and Renewable NRG Systems are set to begin a new collaboration phase to explore the use of LIDAR measurements to actively control the wind turbine, through improved rotor collective pitch and yaw control.