An Evaluation of Vertical Profiles of Wind Speed and Direction within the Turbine Rotor Layer from Remote Sensors as Compared to Hub-height Measurements from Nacelle Mounted Sonic Anemometers.

Measurements from remote sensing instruments, lidars and sodars, have increasingly been applied in wind energy research projects to support commercial development of wind farms. The measurements from acoustic and optical remote sensors and a refined sampling technique of a scanning Doppler lidar provide reliable, high-resolution vertical profiles of wind speed and direction over a several kilometer spatial area. They are suitable for detailed studies of wind flow patterns from the surface through the turbine rotor layer. These capabilities, along with faster instrument deployment and broad observation volume when compared to meteorological masts, can characterize the wind field especially in complex terrain where large spatial wind flow variations may occur.

The presentation includes hub-height wind speed measurements from sodar and scanning Doppler lidar as compared to those of a nacelle-mounted sonic anemometer of a nearby wind turbine. The nearly continuous observations of the wind field over the 18-month period (2016-2017) of the WFIP2 campaign, occurred in the Columbia River Basin, an area with intensive wind energy production. Results will be shown for a variety of wind flow conditions including undisturbed inflow and turbine-waked flow. Analysis results for different time scales, including monthly, seasonal and annual, as well as for different atmospheric or meteorological features observed over the study period and region will be described.