Wind Farm Wake: The 2016 Horns Rev Photo Case

Charlotte Bay Hasager, Nicolai Gayle Nygaard, Patrick Volker, Ioanna Karagali, Søren Juhl Andersen, Jake Badger

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Abstract

Offshore wind farm wakes were observed and photographed in foggy conditions at Horns Rev 2 on 25 January 2016 at 12:45 UTC. These new images show highly contrasting conditions regarding the wind speed, turbulence intensity, atmospheric stability, weather conditions and wind farm wake development as compared to the Horns Rev 1 photographs from 12 February 2008. The paper examines the atmospheric conditions from satellite images, radiosondes, lidar and wind turbine data and compares the observations to results from atmospheric meso-scale modelling and large eddy simulation. Key findings are that a humid and warm air mass was advected from the southwest over cold sea and the dew-point temperature was such that cold-water advection fog formed in a shallow layer. The flow was stably stratified and the freestream wind speed was 13 m/s at hub height, which means that most turbines produced at or near rated power. The wind direction was southwesterly and long, narrow wakes persisted several rotor diameters downwind of the wind turbines. Eventually mixing of warm air from aloft dispersed the fog in the far wake region of the wind farm.
Original languageEnglish
Article number317
JournalEnergies
Volume10
Issue number3
Number of pages24
ISSN1996-1073
DOIs
Publication statusPublished - 2017

Cite this

@article{2ded6419c7354c528434737fb13307c9,
title = "Wind Farm Wake: The 2016 Horns Rev Photo Case",
abstract = "Offshore wind farm wakes were observed and photographed in foggy conditions at Horns Rev 2 on 25 January 2016 at 12:45 UTC. These new images show highly contrasting conditions regarding the wind speed, turbulence intensity, atmospheric stability, weather conditions and wind farm wake development as compared to the Horns Rev 1 photographs from 12 February 2008. The paper examines the atmospheric conditions from satellite images, radiosondes, lidar and wind turbine data and compares the observations to results from atmospheric meso-scale modelling and large eddy simulation. Key findings are that a humid and warm air mass was advected from the southwest over cold sea and the dew-point temperature was such that cold-water advection fog formed in a shallow layer. The flow was stably stratified and the freestream wind speed was 13 m/s at hub height, which means that most turbines produced at or near rated power. The wind direction was southwesterly and long, narrow wakes persisted several rotor diameters downwind of the wind turbines. Eventually mixing of warm air from aloft dispersed the fog in the far wake region of the wind farm.",
author = "Hasager, {Charlotte Bay} and Nygaard, {Nicolai Gayle} and Patrick Volker and Ioanna Karagali and Andersen, {S{\o}ren Juhl} and Jake Badger",
year = "2017",
doi = "10.3390/en10030317",
language = "English",
volume = "10",
journal = "Energies",
issn = "1996-1073",
publisher = "M D P I AG",
number = "3",

}

Wind Farm Wake: The 2016 Horns Rev Photo Case. / Hasager, Charlotte Bay; Nygaard, Nicolai Gayle; Volker, Patrick; Karagali, Ioanna; Andersen, Søren Juhl; Badger, Jake.

In: Energies, Vol. 10, No. 3, 317, 2017.

Research output: Contribution to journalJournal articleResearchpeer-review

TY - JOUR

T1 - Wind Farm Wake: The 2016 Horns Rev Photo Case

AU - Hasager, Charlotte Bay

AU - Nygaard, Nicolai Gayle

AU - Volker, Patrick

AU - Karagali, Ioanna

AU - Andersen, Søren Juhl

AU - Badger, Jake

PY - 2017

Y1 - 2017

N2 - Offshore wind farm wakes were observed and photographed in foggy conditions at Horns Rev 2 on 25 January 2016 at 12:45 UTC. These new images show highly contrasting conditions regarding the wind speed, turbulence intensity, atmospheric stability, weather conditions and wind farm wake development as compared to the Horns Rev 1 photographs from 12 February 2008. The paper examines the atmospheric conditions from satellite images, radiosondes, lidar and wind turbine data and compares the observations to results from atmospheric meso-scale modelling and large eddy simulation. Key findings are that a humid and warm air mass was advected from the southwest over cold sea and the dew-point temperature was such that cold-water advection fog formed in a shallow layer. The flow was stably stratified and the freestream wind speed was 13 m/s at hub height, which means that most turbines produced at or near rated power. The wind direction was southwesterly and long, narrow wakes persisted several rotor diameters downwind of the wind turbines. Eventually mixing of warm air from aloft dispersed the fog in the far wake region of the wind farm.

AB - Offshore wind farm wakes were observed and photographed in foggy conditions at Horns Rev 2 on 25 January 2016 at 12:45 UTC. These new images show highly contrasting conditions regarding the wind speed, turbulence intensity, atmospheric stability, weather conditions and wind farm wake development as compared to the Horns Rev 1 photographs from 12 February 2008. The paper examines the atmospheric conditions from satellite images, radiosondes, lidar and wind turbine data and compares the observations to results from atmospheric meso-scale modelling and large eddy simulation. Key findings are that a humid and warm air mass was advected from the southwest over cold sea and the dew-point temperature was such that cold-water advection fog formed in a shallow layer. The flow was stably stratified and the freestream wind speed was 13 m/s at hub height, which means that most turbines produced at or near rated power. The wind direction was southwesterly and long, narrow wakes persisted several rotor diameters downwind of the wind turbines. Eventually mixing of warm air from aloft dispersed the fog in the far wake region of the wind farm.

U2 - 10.3390/en10030317

DO - 10.3390/en10030317

M3 - Journal article

VL - 10

JO - Energies

JF - Energies

SN - 1996-1073

IS - 3

M1 - 317

ER -