Richard J.A.M. Stevens

Professor at the University of Twente

Wind energy · Turbulence · Environmental flows

Publication 101 · Atmospheric turbulence

Impact of Negative Geostrophic Wind Shear on Wind Farm Performance

A. Stieren, J.H. Kasper, S.N. Gadde, and R.J.A.M. Stevens, PRX Energy 1, 023007 (2022).

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Main finding

The paper tests how a prescribed negative vertical gradient of geostrophic wind changes stable- and neutral-boundary-layer wind-farm performance. Wall-modelled Boussinesq LES uses the AMD SGS closure, concurrent precursor inflow, and actuator-line NREL 5-MW turbines. The 15.36 km x 4.8 km x 4 km domain has 1280 x 640 x 384 points, 12 m x 7.5 m horizontal resolution, 5 m vertical resolution below 1.5 km, and stretching aloft.

Row-averaged wind farm power for three geostrophic shear cases in stable and neutral boundary layers
How to read the figure. Row-averaged turbine power, normalised by the barotropic case, against turbine row for the stable and the neutral boundary layer. Negative geostrophic shear that leaves more wind resource above the rotor holds power above the barotropic case at every row; the opposite gradient holds it below. Figure 12, which normalises each case against its own first row, separates this from the entrance effect. Open the full-resolution figure. Figure 11. A. Stieren et al. (2022). No separate licence is stated here; consult the original publication and credited source before reuse.

Why this matters

Use it to show why a vertical pressure-gradient profile and the resource above the rotor matter.

Research context

The cases vary vertical geostrophic shear together with low-level-jet height and strength, veer, turbulence, and available momentum aloft. Their performance differences therefore cannot be assigned to one scalar measure of baroclinicity.

Coverage of this research

View in the complete publication list Related atmospheric boundary layer research