ENDOW(efficient development of offshore wind farms): modelling wake and boundary layer interactions

Wind Energy ◽  
2004 ◽  
Vol 7 (3) ◽  
pp. 225-245 ◽  
Author(s):  
Rebecca Barthelmie ◽  
Gunner Larsen ◽  
Sara Pryor ◽  
Hans Jørgensen ◽  
Hans Bergström ◽  
...  
Keyword(s):  
Boundary Layer ◽  
Wind Farms ◽  
Offshore Wind ◽  
Offshore Wind Farms

Wind wake effects of large offshore wind farms, an underrated impact on the marine ecosystem?

2020 ◽  
Author(s):  
Corinna Schrum ◽  
Naveed Akhtar ◽  
Nils Christiansen ◽  
Jeff Carpenter ◽  
Ute Daewel ◽  
...  
Keyword(s):  
Boundary Layer ◽  
North Sea ◽  
Large Scale ◽  
Spatial Scales ◽  
Wind Farms ◽  
Offshore Wind ◽  
Offshore Wind Farms ◽  
The North ◽  
The North Sea ◽  
Ocean Hydrodynamics

<p>The North Sea is a world-wide hot-spot in offshore wind energy production and installed capacity is rapidly increasing. Current and potential future developments raise concerns about the implications for the environment and ecosystem. Offshore wind farms change the physical environment across scales in various ways, which have the potential to modify biogeochemical fluxes and ecosystem structure. The foundations of wind farms cause oceanic wakes and sediment fluxes into the water column. Oceanic wakes have spatial scales of about O(1km) and structure local ecosystems within and in the vicinity of wind farms. Spatially larger effects can be expected from wind deficits and atmospheric boundary layer turbulence arising from wind farms. Wind disturbances extend often over muliple tenths of kilometer and are detectable as large scale wind wakes. Moreover, boundary layer disturbances have the potential to change the local weather conditions and foster e.g. local cloud development. The atmospheric changes in turn changes ocean circulation and turbulence on the same large spatial scales and modulate ocean nutrient fluxes. The latter directly influences biological productivity and food web structure. These cascading effects from atmosphere to ocean hydrodynamics, biogeochemistry and foodwebs are likely underrated while assessing potential and risks of offshore wind.</p><p>We present latest evidence for local to regional environmental impacts, with a focus on wind wakes and discuss results from observations, remote sensing and modelling.  Using a suite of coupled atmosphere, ocean hydrodynamic and biogeochemistry models, we quantify the impact of large-scale offshore wind farms in the North Sea. The local and regional meteorological effects are studied using the regional climate model COSMO-CLM and the coupled ocean hydrodynamics-ecosystem model ECOSMO is used to study the consequent effects on ocean hydrodynamics and ocean productivity. Both models operate at a horizontal resolution of 2km.</p>

scholarly journals Observed and simulated turbulent kinetic energy (WRF 3.8.1) overlarge offshore wind farms

2019 ◽  
Author(s):  
Simon K. Siedersleben ◽  
Andreas Platis ◽  
Julie K. Lundquist ◽  
Bughsin Djath ◽  
Astrid Lampert ◽  
...  
Keyword(s):  
Boundary Layer ◽  
Wind Speed ◽  
Wind Farm ◽  
Wind Farms ◽  
Horizontal Resolution ◽  
Offshore Wind ◽  
Vertical Resolution ◽  
Offshore Wind Farms ◽  
The Impact ◽  
Simulated Wind

Abstract. Because wind farms affect local weather and microclimates, parameterizations of their effects have been developed for numerical weather prediction models. While most wind farm parameterizations (WFP) include drag effects of wind farms, models differ on whether or not an additional turbulent kinetic energy (TKE) source should be included in these parameterizations to simulate the impact of wind farms on the boundary layer. Therefore, we use aircraft measurements above large offshore wind farms in stable conditions to evaluate WFP choices. Of the three case studies we examine, we find the simulated ambient background flow to agree with observations of temperature stratification and winds. This agreement allowing us to explore the sensitivity of simulated wind farm effects with respect to modeling choices such as whether or not to include a TKE source, horizontal resolution, vertical resolution, and advection of TKE. For a stably stratified marine atmospheric boundary layer (MABL), a TKE source and a horizontal resolution in the order of 5 km or finer are necessary to represent the impact of offshore wind farms on the MABL. Additionally, TKE advection results in excessively reduced TKE over the wind farms, which in turn causes an underestimation of the wind speed above the wind farm. Furthermore, using fine vertical resolution increases the agreement of the simulated wind speed with satellite observations of surface wind speed.

scholarly journals Turbulent kinetic energy over large offshore wind farms observed and simulated by the mesoscale model WRF (3.8.1)

2020 ◽  
Vol 13 (1) ◽  
pp. 249-268 ◽  
Author(s):  
Simon K. Siedersleben ◽  
Andreas Platis ◽  
Julie K. Lundquist ◽  
Bughsin Djath ◽  
Astrid Lampert ◽  
...  
Keyword(s):  
Boundary Layer ◽  
Wind Speed ◽  
Wind Farm ◽  
Wind Farms ◽  
Horizontal Resolution ◽  
Offshore Wind ◽  
Vertical Resolution ◽  
Offshore Wind Farms ◽  
The Impact ◽  
Simulated Wind

Abstract. Wind farms affect local weather and microclimates; hence, parameterizations of their effects have been developed for numerical weather prediction models. While most wind farm parameterizations (WFPs) include drag effects of wind farms, models differ on whether or not an additional turbulent kinetic energy (TKE) source should be included in these parameterizations to simulate the impact of wind farms on the boundary layer. Therefore, we use aircraft measurements above large offshore wind farms in stable conditions to evaluate WFP choices. Of the three case studies we examine, we find the simulated ambient background flow to agree with observations of temperature stratification and winds. This agreement allows us to explore the sensitivity of simulated wind farm effects with respect to modeling choices such as whether or not to include a TKE source, horizontal resolution, vertical resolution and advection of TKE. For a stably stratified marine atmospheric boundary layer (MABL), a TKE source and a horizontal resolution on the order of 5 km or finer are necessary to represent the impact of offshore wind farms on the MABL. Additionally, TKE advection results in excessively reduced TKE over the wind farms, which in turn causes an underestimation of the wind speed deficit above the wind farm. Furthermore, using fine vertical resolution increases the agreement of the simulated wind speed with satellite observations of surface wind speed.

scholarly journals A new spectrum model for the atmospheric crosswind component applicable from mesoscales to microscales

2020 ◽  
Author(s):  
Xiaoli Larsén ◽  
Søren Larsen ◽  
Erik Petersen ◽  
Torben Mikkelsen
Keyword(s):  
Boundary Layer ◽  
Time Series ◽  
Wind Direction ◽  
Wind Farms ◽  
Offshore Wind ◽  
Frequency Range ◽  
Layer Model ◽  
Offshore Wind Farms ◽  
Boundary Layer Model ◽  
Spectrum Model

<p>A crosswind spectrum model <em>S</em><sub>v</sub>(<em>f</em>) is proposed that covers both the meso and the microscale, ranging in frequency 1/5 day<sup>-1</sup> to the turbulence inertial subrange. The purpose is to improve the calculation of flow meandering effect over areas of the sizes of offshore wind farms and clusters.</p><p>The development is based on measurement (from Høvsøre) analysis over this broad frequency range for cases where wind direction does not change much during a day. The model reads:</p><p><em>fS</em><sub>v</sub>(<em>f</em>) = Boundary-layer model   for <em>f</em>><em>f</em><sub>1</sub>,</p><p>         = Constant                           for <em>f</em><sub>2</sub><<em>f</em><<em>f</em><sub>1</sub>,</p><p>         = <em>a</em><sub>1</sub><em>f </em><sup>-2/3 </sup>+ <em>a</em><sub>2</sub><em>f </em><sup>-2</sup>                     for f<f<sub>2</sub></p><p>Here, the frequency range <em>f</em><sub>2</sub> to <em>f</em><sub>1</sub> defines the gap region, and the constant in this subrange is determined by the spectra on both sides of this range; the boundary-layer model used here is either the Kaimal model or the Mikkelsen-Tchen model; <em>a</em><sub>1</sub> and <em>a</em><sub>2</sub> are climatological coefficients. The credibility of the model is evaluated against with measurements from another wind test site Østerild, with measurements ranging in height from surface layer to a height of 241 m.   </p><p>The model is used together with a similar model for the longitudinal wind component u to obtain time series u(t) and v(t), from which direction statistics are obtained and compared with those from measurements. It was found that the boundary-layer models could only describe stationary time series for wind vectors. The new v-spectral model improves significantly the statistics of wind direction variation over scales that correspond to offshore wind farms and clusters.</p>

Disturbance of harbour porpoises during construction of the first seven offshore wind farms in Germany

2018 ◽  
Vol 596 ◽  
pp. 213-232 ◽  
Author(s):  
MJ Brandt ◽  
AC Dragon ◽  
A Diederichs ◽  
MA Bellmann ◽  
V Wahl ◽  
...  
Keyword(s):  
Wind Farms ◽  
Offshore Wind ◽  
Offshore Wind Farms

Feasibility study for the installation of offshore wind farms in the Canary Islands

2009 ◽  
Vol 1 (07) ◽  
pp. 809-813
Author(s):  
M. Martínez ◽  
A. Pulido ◽  
J. Romero ◽  
N. Angulo ◽  
F. Díaz ◽  
...  
Keyword(s):  
Feasibility Study ◽  
Canary Islands ◽  
Wind Farms ◽  
Offshore Wind ◽  
Offshore Wind Farms

scholarly journals Offshore wind farms and the attraction–production hypothesis: insights from a combination of stomach content and stable isotope analyses

Hydrobiologia ◽  
2021 ◽  
Author(s):  
Ninon Mavraki ◽  
Steven Degraer ◽  
Jan Vanaverbeke
Keyword(s):  
Stable Isotope ◽  
Stomach Content ◽  
Wind Farms ◽  
Offshore Wind ◽  
Artificial Reefs ◽  
Dietary Composition ◽  
Trachurus Trachurus ◽  
Offshore Wind Farms ◽  
Scomber Scombrus ◽  
Isotope Analyses

AbstractOffshore wind farms (OWFs) act as artificial reefs, attracting high abundances of fish, which could potentially increase their local production. This study investigates the feeding ecology of fish species that abundantly occur at artificial habitats, such as OWFs, by examining the short- and the long-term dietary composition of five species: the benthopelagic Gadus morhua and Trisopterus luscus, the pelagic Scomber scombrus and Trachurus trachurus, and the benthic Myoxocephalus scorpioides. We conducted combined stomach content and stable isotope analyses to examine the short- and the time-integrated dietary composition, respectively. Our results indicated that benthopelagic and benthic species utilize artificial reefs, such as OWFs, as feeding grounds for a prolonged period, since both analyses indicated that they exploit fouling organisms occurring exclusively on artificial hard substrates. Trachurus trachurus only occasionally uses artificial reefs as oases of highly abundant resources. Scomber scombrus does not feed on fouling fauna and therefore its augmented presence in OWFs is probably related to reasons other than the enhanced food availability. The long-termed feeding preferences of benthic and benthopelagic species contribute to the hypothesis that the artificial reefs of OWFs could potentially increase the fish production in the area. However, this was not supported for the pelagic species.

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