For wind turbines in complex terrain, the devil is in the detail

Julia Lange, Jakob Mann, Jacob Berg, Dan Parvu, Ryan Kilpatrick, Adrian Costache, Jubayer Chowdhury, Kamran Siddiqui, Horia Hangan

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Abstract

The cost of energy produced by onshore wind turbines is among the lowest available; however, onshore wind turbines are often positioned in a complex terrain, where the wind resources and wind conditions are quite uncertain due to the surrounding topography and/or vegetation. In this study, we use a scale model in a three-dimensional wind-testing chamber to show how minor changes in the terrain can result in significant differences in the flow at turbine height. These differences affect not only the power performance but also the life-time and maintenance costs of wind turbines, and hence, the economy and feasibility of wind turbine projects. We find that the mean wind, wind shear and turbulence level are extremely sensitive to the exact details of the terrain: a small modification of the edge of our scale model, results in a reduction of the estimated annual energy production by at least 50% and an increase in the turbulence level by a factor of five in the worst-case scenario with the most unfavorable wind direction. Wind farm developers should be aware that near escarpments destructive flows can occur and their extent is uncertain thus warranting on-site field measurements.
Original languageEnglish
Article number094020
JournalEnvironmental Research Letters
Volume12
Issue number9
Number of pages8
ISSN1748-9326
DOIs
Publication statusPublished - 2017

Keywords

  • Wind power plants
  • Energy resources
  • Geophysical techniques and equipment
  • terrain mapping
  • wind power
  • wind turbines
  • onshore wind turbines
  • energy cost
  • wind resources
  • wind conditions
  • scale model
  • three-dimensional wind-testing chamber
  • life-time costs
  • maintenance costs
  • mean wind
  • wind shear
  • turbulence level
  • estimated annual energy production reduction
  • on-site field measurements

Cite this

Lange, J., Mann, J., Berg, J., Parvu, D., Kilpatrick, R., Costache, A., Chowdhury, J., Siddiqui, K., & Hangan, H. (2017). For wind turbines in complex terrain, the devil is in the detail. Environmental Research Letters, 12(9), [094020]. https://doi.org/10.1088/1748-9326/aa81db