10.2    Best practices for simulating wind farm wakes with the WRF Wind Farm Parameterization.

Tomaszewski, Jessica M., University of Colorado Boulder (CU Boulder), and Julie K. Lundquist, CU Boulder and the National Renewable Energy Laboratory

Wind farm wakes can extend over 50 km downwind in stably stratified conditions and pose significant consequences on downwind power production and subsequent revenue. As such, wind farm wake impacts must be considered in wind resource assessments and planning.
The Weather Research and Forecasting (WRF) model includes a Wind Farm Parameterization (WFP) to estimate wind farm wake effects, but model configuration choices can influence the resulting predictions of wind farm wakes. These choices include vertical resolution, horizontal resolution, and whether or not to include the addition of turbulent kinetic energy generated by the spinning wind turbines. Despite the sensitivity to model configuration, no clear guidance currently exists on these options.
“Best practices” can be defined by comparing simulated wind farm wakes produced by varying model configurations with observations from operating wind plants or from in-situ meteorological observations. Here we present recommendations for running WRF WFP based on simulations compared with turbine power production observations from an onshore wind farm in flat terrain over several diurnal cycles. Results suggest that a horizontal resolution of 3 km or 1 km paired with a vertical resolution of 10 m provides the most accurate representation of wind farm wake effects.