Projects

Worldwide close to the wind

Our experts are operating worldwide. Our selection of special projects provides an overview about the most relevant aspects. The filtering function enables an easy access to single projects.

 

Wind park optimisation of 40 planned wind turbines

Site: Bosnia-Herzegovina

Results:

  • due to a pronounced main wind direction the planning of the wind turbines was modified to one single row instead of two with short distances between the turbines
  • better placing on a mountain ridge possible

 

Development of an optimum wind farm layout using four met masts

Site: Western Canada

Results:

  • The influence of the nearby sea is strongly overestimated by the model, this could be solved through a modified modelling of the roughness lengths.
  • Poor quality of the met mast data, inconsistent anemometer data
  • Due to the measurement heights being close together, no reliable vertical extrapolation is possible.
  • A first layout of the wind farm was developed. Due to a pronounced main wind direction, the wind turbines ware placed in several rows, with an adequate distance between these. However, the distance between neighbouring turbines could be strongly reduced.
Re-assessment of wake losses

Site: small wind farm in Germany; the client assumes distinctly higher wake losses than calculated in the original assessment report

Procedure: profound analysis of SCADA data, adapted model calculations

Results:

  • the met station data used in the wind assessment report turned out to be less appropiate for the site, which is influenced by very local effects, thus the wind rose of the met station is less representative
  • the frequency distribution of the wind speed of the met station data is also not representative for the site
  • thrust coefficients of the power curve of the wind turbines are too low as has often been observed by aj for this specific turbines manufacturer
  • very low turbulence at the site, i.e. the calculated wake losses are too low

Final result: wake losses more than doubled compared to the original calculations

Performance check of wind turbines

Site: medium size wind farm in Belgium

Procedure:

  • combination of analyses of SCADA data and a nearby wind measurement
  • comparison to reanalyses data, met station data and aj production indices

Results:

  • inconsistencies related to the power curve could be detected in the past, including longer periods with reduced availabilities and a variety of curtailments
  • more recently, the operational behaviour of the turbines has improved; however, some inconsistencies still occur around rated wind speed which need to be analysed further with respect to an additional load on the turbines
  • realistic performance of the wind turbines in the wake of neighbouring turbines, i.e. no under-performance with respect to the power curve
Re-assessment of energy production

Site: medium size wind farm in Northern Germany; the real energy production is much lower than calculated in the original assessment report

Procedure: profound analysis of SCADA data

Results:

  • reduction of the long term mean wind resource, albeit its contribution to the overall result is small compared to the following aspects
  • thrust coefficients too low
  • power curves are not reached in the wake of neighbouring turbines
  • strong deflection of the flow due to the specific wind farm layout in terms of very low distances between wind turbines
Re-assessment of energy production

Site: medium size wind farm in Eastern Germany

Procedure: 

  • profound analysis of SCADA data and monthly production data
  • wind measurement with a Sodar instrument used for comparison purposes
  • comparison of all data with a neighbouring wind farm
  • model calculations

Results:

  • reduction of the long term mean energy production has a significant contribution to the overall difference between the predicted and the real energy production
  • calculation of wake losses is realistic
  • the total energy production of the main comparison wind farm in the original assessment report with wind turbines of the same manufacturer is significantly higher than predicted and as could be expected considering the location of the wind farm, however the procution data could be verified by the feeded energy production
  • the new wind turbines are a new type of the same manufacturer, however, the predicted power curves differ significantly from those of the comparison turbines
3 wind measurements in parallel: met mast, Sodar and Lidar

Site: Black Forest, Germany

Results:

  • the vertical wind profile of the met mast showed implausible values
  • data of a Sodar instrument from an external company were also considered implausibe, therefore a Sodar instrument of the manufacturer AQ Systems was used afterwards
  • strong consistency between the AQ Systems Sodar and the Lidar
Expertise