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Observed Thermal Impacts of Wind Farms Over Northern Illinois.

Slawsky LM, Zhou L, Baidya Roy S, Xia G, Vuille M, Harris RA - Sensors (Basel) (2015)

Bottom Line: The nighttime LST warming effect varies with seasons, with the strongest warming in winter months of December-February, and the tightest spatial coupling in summer months of June-August.Although the warming effect is strongest in winter, the spatial coupling is more erratic and spread out than in summer.These results suggest that the observed warming signal at nighttime is likely due to the net downward transport of heat from warmer air aloft to the surface, caused by the turbulent mixing in the wakes of the spinning turbine rotor blades.

View Article: PubMed Central - PubMed

Affiliation: Department of Atmospheric and Environmental Sciences, SUNY at Albany, Albany, NY 12222, USA. lslawsky@albany.edu.

ABSTRACT
This paper assesses impacts of three wind farms in northern Illinois using land surface temperature (LST) data from the Moderate Resolution Imaging Spectroradiometer (MODIS) instruments onboard the Terra and Aqua satellites for the period 2003-2013. Changes in LST between two periods (before and after construction of the wind turbines) and between wind farm pixels and nearby non-wind-farm pixels are quantified. An areal mean increase in LST by 0.18-0.39 °C is observed at nighttime over the wind farms, with the geographic distribution of this warming effect generally spatially coupled with the layout of the wind turbines (referred to as the spatial coupling), while there is no apparent impact on daytime LST. The nighttime LST warming effect varies with seasons, with the strongest warming in winter months of December-February, and the tightest spatial coupling in summer months of June-August. Analysis of seasonal variations in wind speed and direction from weather balloon sounding data and Automated Surface Observing System hourly observations from nearby stations suggest stronger winds correspond to seasons with greater warming and larger downwind impacts. The early morning soundings in Illinois are representative of the nighttime boundary layer and exhibit strong temperature inversions across all seasons. The strong and relatively shallow inversion in summer leaves warm air readily available to be mixed down and spatially well coupled with the turbine. Although the warming effect is strongest in winter, the spatial coupling is more erratic and spread out than in summer. These results suggest that the observed warming signal at nighttime is likely due to the net downward transport of heat from warmer air aloft to the surface, caused by the turbulent mixing in the wakes of the spinning turbine rotor blades.

No MeSH data available.


Related in: MedlinePlus

Geographic location of three wind farms labeled WFA, WFB, and WFC, built between 2007 and 2010, together with (a) two sounding station sites (KILX and KDVN) and one Automated Surface Observing System (ASOS) station site (PNT) and (b) individual wind turbines over the study region (40.86°N–41.34°N, 88.82°W–88.30°W). Plus symbols represent individual wind turbines; (c) Definition of wind farm pixels (WFPs, 270 pixels in red) and nearby non-wind farm pixels (NNWFPs, 400 pixels in black) at 0.01° resolution. WFPs contain at least one wind turbine; (d) Definition of upwind wind farm pixels (UWFPs, 141 pixels in orange) and downwind wind farm pixels (DWFPs, 300 pixels in blue) at 0.01° resolution. DWFPs and UWFPs are located between WFPs and NNWFPs.
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sensors-15-14981-f001: Geographic location of three wind farms labeled WFA, WFB, and WFC, built between 2007 and 2010, together with (a) two sounding station sites (KILX and KDVN) and one Automated Surface Observing System (ASOS) station site (PNT) and (b) individual wind turbines over the study region (40.86°N–41.34°N, 88.82°W–88.30°W). Plus symbols represent individual wind turbines; (c) Definition of wind farm pixels (WFPs, 270 pixels in red) and nearby non-wind farm pixels (NNWFPs, 400 pixels in black) at 0.01° resolution. WFPs contain at least one wind turbine; (d) Definition of upwind wind farm pixels (UWFPs, 141 pixels in orange) and downwind wind farm pixels (DWFPs, 300 pixels in blue) at 0.01° resolution. DWFPs and UWFPs are located between WFPs and NNWFPs.

Mentions: Illinois had the fourth most installed wind power capacity in the United States by the end of 2013 [22]. The study region chosen here (Figure 1) is in the northern part of Illinois (40.86° N–41.34° N, 88.82° W–88.30° W), and lies between La Salle, Livingston, and Grundy counties and encompasses three different wind farms, referred to as WFA, WFB, and WFC. The height of wind turbines, defined as hub-height, is measured by the distance from the turbine platform to the rotor, not including the length of the rotor blades. WFA is located in La Salle County and has 140 General Electric (GE) Company turbines standing at 80 m hub-height with an electrical power output capacity of 1.5 MW each. The construction began in 2007 and it came online (the turbines start spinning and producing electricity) during 2008 and 2009. WFB is located at the boundary of La Salle County and Grundy County, to the north of Livingston County. It consists of 200 1.5 MW GE turbines of 80 m hub-height, coming online in 2009 and 2010. Both WFA and WFB turbines have rotor diameters of about 80 m. WFC is in Livingston County and consists of 150 Gamesa G-87 2.0 MW turbines with 67 m hub-height and 87 m rotor diameter. The construction began in 2009 and WFC came online in 2010.


Observed Thermal Impacts of Wind Farms Over Northern Illinois.

Slawsky LM, Zhou L, Baidya Roy S, Xia G, Vuille M, Harris RA - Sensors (Basel) (2015)

Geographic location of three wind farms labeled WFA, WFB, and WFC, built between 2007 and 2010, together with (a) two sounding station sites (KILX and KDVN) and one Automated Surface Observing System (ASOS) station site (PNT) and (b) individual wind turbines over the study region (40.86°N–41.34°N, 88.82°W–88.30°W). Plus symbols represent individual wind turbines; (c) Definition of wind farm pixels (WFPs, 270 pixels in red) and nearby non-wind farm pixels (NNWFPs, 400 pixels in black) at 0.01° resolution. WFPs contain at least one wind turbine; (d) Definition of upwind wind farm pixels (UWFPs, 141 pixels in orange) and downwind wind farm pixels (DWFPs, 300 pixels in blue) at 0.01° resolution. DWFPs and UWFPs are located between WFPs and NNWFPs.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4541818&req=5

sensors-15-14981-f001: Geographic location of three wind farms labeled WFA, WFB, and WFC, built between 2007 and 2010, together with (a) two sounding station sites (KILX and KDVN) and one Automated Surface Observing System (ASOS) station site (PNT) and (b) individual wind turbines over the study region (40.86°N–41.34°N, 88.82°W–88.30°W). Plus symbols represent individual wind turbines; (c) Definition of wind farm pixels (WFPs, 270 pixels in red) and nearby non-wind farm pixels (NNWFPs, 400 pixels in black) at 0.01° resolution. WFPs contain at least one wind turbine; (d) Definition of upwind wind farm pixels (UWFPs, 141 pixels in orange) and downwind wind farm pixels (DWFPs, 300 pixels in blue) at 0.01° resolution. DWFPs and UWFPs are located between WFPs and NNWFPs.
Mentions: Illinois had the fourth most installed wind power capacity in the United States by the end of 2013 [22]. The study region chosen here (Figure 1) is in the northern part of Illinois (40.86° N–41.34° N, 88.82° W–88.30° W), and lies between La Salle, Livingston, and Grundy counties and encompasses three different wind farms, referred to as WFA, WFB, and WFC. The height of wind turbines, defined as hub-height, is measured by the distance from the turbine platform to the rotor, not including the length of the rotor blades. WFA is located in La Salle County and has 140 General Electric (GE) Company turbines standing at 80 m hub-height with an electrical power output capacity of 1.5 MW each. The construction began in 2007 and it came online (the turbines start spinning and producing electricity) during 2008 and 2009. WFB is located at the boundary of La Salle County and Grundy County, to the north of Livingston County. It consists of 200 1.5 MW GE turbines of 80 m hub-height, coming online in 2009 and 2010. Both WFA and WFB turbines have rotor diameters of about 80 m. WFC is in Livingston County and consists of 150 Gamesa G-87 2.0 MW turbines with 67 m hub-height and 87 m rotor diameter. The construction began in 2009 and WFC came online in 2010.

Bottom Line: The nighttime LST warming effect varies with seasons, with the strongest warming in winter months of December-February, and the tightest spatial coupling in summer months of June-August.Although the warming effect is strongest in winter, the spatial coupling is more erratic and spread out than in summer.These results suggest that the observed warming signal at nighttime is likely due to the net downward transport of heat from warmer air aloft to the surface, caused by the turbulent mixing in the wakes of the spinning turbine rotor blades.

View Article: PubMed Central - PubMed

Affiliation: Department of Atmospheric and Environmental Sciences, SUNY at Albany, Albany, NY 12222, USA. lslawsky@albany.edu.

ABSTRACT
This paper assesses impacts of three wind farms in northern Illinois using land surface temperature (LST) data from the Moderate Resolution Imaging Spectroradiometer (MODIS) instruments onboard the Terra and Aqua satellites for the period 2003-2013. Changes in LST between two periods (before and after construction of the wind turbines) and between wind farm pixels and nearby non-wind-farm pixels are quantified. An areal mean increase in LST by 0.18-0.39 °C is observed at nighttime over the wind farms, with the geographic distribution of this warming effect generally spatially coupled with the layout of the wind turbines (referred to as the spatial coupling), while there is no apparent impact on daytime LST. The nighttime LST warming effect varies with seasons, with the strongest warming in winter months of December-February, and the tightest spatial coupling in summer months of June-August. Analysis of seasonal variations in wind speed and direction from weather balloon sounding data and Automated Surface Observing System hourly observations from nearby stations suggest stronger winds correspond to seasons with greater warming and larger downwind impacts. The early morning soundings in Illinois are representative of the nighttime boundary layer and exhibit strong temperature inversions across all seasons. The strong and relatively shallow inversion in summer leaves warm air readily available to be mixed down and spatially well coupled with the turbine. Although the warming effect is strongest in winter, the spatial coupling is more erratic and spread out than in summer. These results suggest that the observed warming signal at nighttime is likely due to the net downward transport of heat from warmer air aloft to the surface, caused by the turbulent mixing in the wakes of the spinning turbine rotor blades.

No MeSH data available.


Related in: MedlinePlus