Site assessment

Benefit from our competence of more than 20 years of research and development in wind energy meteorology.

The determination of the wind potential and the energy yield calculation for wind farms are the focal points of the anemos GmbH. Our core competence is the analysis of wind information and the numerical atmospheric modeling on all spatial and temporal scales.

Based on existing wind information and the specific site characteristics we develop an adequate concept for the evaluation of your wind farm project. This concept includes wind measurements, data analyses and numerical modeling, combined in order to minimize the uncertainty. We apply different numerical models and varying analysis procedures. We have the competence as well as the infrastructure for even the most complex atmospheric flow simulations.

The influence of restrictions due to shade impact or sound emissions, variable operation modes for the protection of animal life or sector management is determined by statistical means and time series analysis. A detailed uncertainty consideration, transgression probabilities and information on wind volatility and extreme wind conditions provide the basis for risk assessment.

Wind potential map

windptential

A wind potential study (wind mapping) often forms the first step in wind farm planning. It is suitable for a rather large-scale view on the spatial wind distribution or the detailed search for sites suitable for measuring campaigns or the installation of wind farms.

The spatial resolution may be chosen depending on the client's requirements: from a few hundred meters up to several kilometers. anemos disposes of suitable flow models and their combinations, applicable from local to continental scale.

As a result you receive a colored wind map with the mean long-year wind speeds for the specified horizontal resolution and height a.g.l. Additionally, the map includes the most important topographic objects (cities, streets) which enable an easy identification of the areas with favourable wind speeds.
In case you need continuous, time-dependent wind information (e.g. daily or annual course, long-term time series), the anemos wind atlases are available.

Energy yield calculations

We accompany your project from the first energy yield estimation over wind measurements to the final bankable wind study as a basis for your financial considerations. Whether for the long-term correlation of wind measurements or energy yield data of reference turbines, or to drive the more complex flow models ‐ the data of our wind atlases are applied in almost every wind study as an additional information source.

Based on the site characteristic and existing wind information we either apply simple boundary layer models such as WAsP or complex CFD-models for the wind potential calculations. The reports are prepared according to the Technical Guideline TR6 which defines the high-quality standards of German site assessment studies. This Technical Guideline may be purchased from FGW, the Fördergesellschaft Windenergie und andere Erneuerbare Energien e.V..

CFD simulations

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Estimating the wind conditions over complex terrain is a big challenge. anemos operates the CFD model Meteodyn WT which is especially developed to calculate the flow over complex terrain.

To provide site assessment studies with such a complex model in reasonable time, the anemos company operates high-performance computers that are able to perform these complex computations in a adequate time.

  • Performance in complex terrain
  • Standard resolution of 25m (orf even higher)
  • Advanced modeling of forest canopies
  • Integration of different atmospheric stability classes
  • Advanced modeling of the atmospheric turbulence

The result is a detailed and comprehensive evaluation of the wind conditions at your site:

cfd
  • Wind speed and wind direction
  • Energy output of planned and existing wind turbines
  • Wind direction distribution
  • Vertical wind angle
  • Turbulence intensity
  • Wind energy density
  • Wind shear
  • Extreme wind conditions

Risk analysis

uncertency

The risk of an investment in a wind farm project is basically determined by the energy yield calculations and the corresponding uncertainty. The uncertainty consideration in a site assessment study usually refers to the applied methods and data base. Apart from these rather technical uncertainties, a comprehensive risk analysis should include the uncertainty of the natural wind variations from year to year.

An analysis of this wind volatility is prepared based on the long-year high-resolution time series of the anemos wind atlas.

Offshore

offshore1

The offshore wind field may exhibit a strong spatial variation which cannot be adequately considered with a simple extrapolation of the wind potential from coastal weather stations or offshore measurement locations. For the horizontal and vertical extrapolation, and for the deduction of an offshore wind index, we apply our complex 3-dimensional atmospheric models. A parameterization of the roughness depending on the sea conditions is taken into account as well as the atmospheric stability which influences the vertical wind profile changing with the temperature layering and the diurnal and annual courses of temperature above sea or land surfaces.

Our offshore wind atlases are correlated with the measurements at the FINO platforms in the North and Baltic Sea. By this we obtain a detailed 3-dimensional picture of the wind field above sea, adapted to the measurements. These long-term time series are then applied to determine a wind index.

The offshore wind potential studies / site assessment studies of the anemos GmbH meet the common Metocean data requirements.

Turbulence intensity

turbulence intensity

The characteristic ambient turbulence influences the required distances for wind turbines. We calculate the turbulence intensity caused by the surrounding environment with two different methods in order to minimize the uncertainty inherent in the determination of this parameter.

The comparison of these calculated turbulences with real measurements is a part of our quality management. Thus, a more and more sophisticated estimation of the environmental parameters influencing the turbulence intensity is possible.



Shade and noise

schatten
Immissionsberechnungen

The calculation of noise imissions and shade impact is an integral part of wind park planning.

We calculate the impact for the near surroundings according to the respective guidelines and thus help avoiding possible conflicts already in the early planning phase.