Wind farm wake recovery: Space constraints and electrical tie-in costs force many wind farms to be constructed within close proximity of other wind farms. The low-momentum/high-turbulence wake downwind of large wind farms may require 50 km or more to recover, undermining the energy generation potential of downwind farms. The recovery of the wind farm wake is a complex superposition of individual turbine wakes interacting with the atmospheric boundary layer (ABL) as well as the internal boundary layer developed within the wind farm. We are conducting large-scale large eddy simulations to evaluate current wake models and propose modifications to better predict the overall wake recovery and its impact on neighbouring wind farms.
Large eddy simulation results of a wind farm consisting of 100 5MW turbines. Colors show velocity magnitude at hub height.
Wind farm blockage: The blockage effect produces a deceleration of the flow upstream of a turbine due to the removal of momentum at the turbine rotor disk. Historically, the blockage effect was predicted from vortex theory to have a negligible impact beyond three rotor diameters upstream of a rotor. However, recent field measurements suggest blockage may be significantly stronger due to interactions with gravity waves created in the atmospheric boundary layer. This omission has immediate economic impacts and hinders the development of wind projects.
Large eddy simulation of a large finite wind farm. Wind farm consists of 100 5MW turbines. Colors show velocity at hub height.