A numerical study of surface air temperature response to vertical mixing and momentum extraction by wind farms and the impacts of wind farms on mesoscale boundaries

Cervarich, Matthew

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https://hdl.handle.net/2142/46822 Copy

Description

Title

A numerical study of surface air temperature response to vertical mixing and momentum extraction by wind farms and the impacts of wind farms on mesoscale boundaries

Author(s)

Cervarich, Matthew

Issue Date

2014-01-16T18:17:20Z

Director of Research (if dissertation) or Advisor (if thesis)

Baidya Roy, Somnath

Department of Study

Atmospheric Sciences

Discipline

Atmospheric Sciences

Degree Granting Institution

University of Illinois at Urbana-Champaign

Degree Name

M.S.

Degree Level

Thesis

Keyword(s)

• Atmospheric Science
• Boundary Layer Meteorology
• Wind Turbines
• Wind Farms
• Weather Research and Forecasting Model (WRF)
• numerical modeling
• Wind Farm Impacts

Abstract

Wind turbines have been shown to impact their local microclimate. With the increasing areal coverage of wind farms it has become increasingly important to answer scientific questions regarding these impacts. In this thesis, a high resolution numerical model is employed to explore the response of land surface and near surface air temperatures within and in the immediate vicinity of large wind farms in west central Texas to changes in the turbines’ thrust and TKE coefficients during meteorological summers. A control run with no wind turbines is compared to three experimental tests, each with differing thrust and TKE coefficients. The experimental tests are fist compared to observed data from the Moderate Resolution Imaging Spectroradiometer (MODIS) data on the Terra and Aqua Satellites. It is shown that the observed impact of wind farms is greater than the numerically modeled impact. Second, the control run is compared to the experimental tests. The non-linear interaction of hub height wind speeds, thrust coefficients, and TKE coefficients along with the wind turbine layer static stability determine the temperature change impact. During night, statically stable conditions result in strong warming signals while during the day near-neutral conditions result in insignificant impacts. The magnitude of the signal is determined by non-linear interactions between the wind turbines’ thrust coefficient and the vertical wind speed. The high resolution numerical model is also used to analyze the propagation of mesoscale boundaries near and through the wind farm. When compared to the control run, the experimental simulation shows an acceleration of the propagation of the mesoscale boundaries when the boundaries approached the wind farms and a deceleration as the boundaries propagated away from the wind farms. Due to the reduction of winds by the wind farms, boundaries propagating away from the wind farms experience less winds behind the boundaries and propagation speeds are reduced. Boundaries propagating towards wind farms experience less winds ahead of the wind farms and propagation speeds increase.

Graduation Semester

2013-12

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http://hdl.handle.net/2142/46822

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Copyright 2013 Matthew Cervarich

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