Abstract

Wind plant blockage reduces the wind velocity upstream undermining turbine performance for the first row of the plant. We assess how atmospheric stability modifies the induction zone of a wind plant in flat terrain. We also explore different approaches to quantifying the magnitude and extent of the induction zone from field-like observations. To investigate the influence from atmospheric stability, we compare simulations of two stable boundary layers using the Weather Research and Forecasting model in large-eddy simulation mode, representing wind turbines using the generalized actuator disk approach. We find a faster cooling rate at the surface, which produces a stronger stably stratified boundary layer, amplifies the induction zone of both an isolated turbine and of a large wind plant. A statistical analysis on the hub-height wind speed field shows wind slowdowns only extend far upstream (up to 15D) of a wind plant in strong stable boundary layers. To evaluate different ways of measuring wind plant blockage from field-like observations, we consider various ways of estimating the freestream velocity upstream of the plant. Sampling a large area upstream is the most accurate approach to estimating the freestream conditions, and thus of measuring the blockage effect. Also, the choice of sampling method may induce errors of the same order as the velocity deficit in the induction zone.

Highlights

  • Wind turbines extract kinetic energy from the wind, thereby reducing its velocity downstream

  • We find a faster cooling rate at the surface, which produces a stronger stably stratified boundary layer, amplifies the induction zone of both an isolated turbine and of a large wind plant

  • We reduce the fetch required to develop three-dimensional turbulence in the nested Large-eddy simulations (LES) domain using the cell-perturbation 140 method (CPM) from Muñoz-Esparza et al (2014, 2015)

Read more

Summary

Introduction

Wind turbines extract kinetic energy from the wind, thereby reducing its velocity downstream. Experimental results and most numerical simulations suggest wind speed slowdowns that are one order of magnitude smaller at a distance of 2D upstream of the first row of turbines (Bleeg et al, 2018; Wu and Porté-Agel, 2017; Segalini and Dahlberg, 2019; Schneemann et al, 2021). 60 Just as wind speed and atmospheric stability affect turbine power production (Wharton and Lundquist, 2012; Vanderwende and Lundquist, 2012; St. Martin et al, 2016) and wake structure (Bodini et al, 2017; Rhodes and Lundquist, 2013), the induction zone of a wind plant is modified with atmospheric static stability (Allaerts and Meyers, 2018; Schneemann et al, 2021; Wu and Porté-Agel, 2017). We investigate (1) if a stronger stably stratified boundary layer amplifies the wind speed deficit upstream of a large wind plant, and (2) different methodologies for defining the freestream velocity used to quantify the blockage effect in experimental setups.

Large-eddy simulation setup
Turbulence generation in stable boundary layers
The induction zone of a wind plant
Findings
Discussion and conclusions
Full Text
Paper version not known

Talk to us

Join us for a 30 min session where you can share your feedback and ask us any queries you have

Schedule a call

Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.