Wind turbine wake losses would deprive a downstream wind turbine of 70% of its generation capacity at 350m immediately downwind of a modern wind turbine, 50% at 700m, 40% at 1km, 20% at 2km and 10% at 4km. This is based on the Jensen model and case studies tabulated in this data-file. More recently, some sources fear larger extended wake losses that could strain wind deployment.
Wind turbines harvest energy from a mass of moving air via the physics of wind generation. Inherently, this means that the air moving across the turbine must slow down and become more turbulent.
Wind turbine wake losses describe the tendency for downstream turbines to suffer lower output, as their own input air becomes contaminated by the wakes of upstream turbines (schematic below).
Wind turbine wake losses can be modeled using the Jensen Equations, as a function of wind turbine diameter, downstream distances and a wake loss coefficient, as captured in the data-file, and the blue-line above.
Real-world case studies published by operators, and in technical papers are also tabulated in the data file, and peak losses correspond quite closely to the levels predicted by the Jensen model.
Although more recently, some sources challenge whether extended wake losses are larger than modeled, and could be as high as 20% over a distance of 50km, leading to “wind theft”, between one project and another, or even one country and another.
Technical papers on wind farm wake losses are summarized on the final tab of the model, including methods to mitigate wake losses via yaw misalignment and/or pitch control.
Overall, our forecasts for wind and solar capacity additions and global electricity generation are being updated to reflect the total resource sizes of wind and solar, with solar potential seeming 20-100x larger than wind potential.