Betydningen af skyggevirkninger i og mellem parker

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1 Betydningen af skyggevirkninger i og mellem parker Wolfgang Scle, Anja Neubert, Lars Landberg Ejerskab af vindmøller i udlandet :: 8 oktober 2009

2 Overview Te problem(s) Large wakes Modelling (two aspects) Results Conclusions Intro Te Problems Large Wakes Modelling Results Conclusions

4 Te Problems We do not (fully) understand te pysics beind wakes in large off-sore wind farms Classic models do not model effects accurately We ave very few data points for validation Model will depend on: Geometry Wind speed Stability Heigt Radius Intro Te Problems Large Wakes Modelling Results Conclusions

5 Please do not forget: Te great majority of wind farms are analysed accurately using te standard WindFarmer Eddy Viscosity wake model.

6 Large offsore wind farm ~ 5km Wat is a large offsore wind farm? R1 R2 R3 Offsore, >4x4 turbines, >5 rows deep R4 R5 R6 ~ 4km Horns Rev: 80 x V80 R7 R8 Nysted: 72 x SWT 2.3 C1 C2 C3 C4 C5 C6 C7 C8 C9 C10 Intro Te Problems Large Wakes Modelling Results Conclusions

7 Horns Rev offsore wind farm (Scadaview data) 240 deg, 9m/s power relative to turbine turbine number SCADA data WF EV wit IBL model WF EV witout IBL model Turbine by turbine, free wind speed 9 m/s, deg, WF offsore wake model 2006 Intro Te Problems Large Wakes Modelling Results Conclusions

8 Detailed Horns Rev Data and Classical Wake Model Row-average power at 10m/s, Row Normalised Average Power Measured Measured Measured EV Model EV Model EV Model WTG No Intro Te Problems Large Wakes Modelling Results Conclusions

9 Large wind farm wake model Model describes an ambient wind speed correction Modification of te wind profile beind turbines Geometric model considers density of turbines Wake recovery ramped over fixed interval Properties Correction is calculated turbine to turbine Considers turbine geometry Considers layout geometry Allows easy modification of wind farm layout Can be used in combination wit classical models Intro Te Problems Large Wakes Modelling Results Conclusions

10 Wind speed profile

11 Large wind farm wake model Standard internal boundary layer (rougness cange) Intro Te Problems Large Wakes Modelling Results Conclusions

12 Standard internal boundary layer (rougness cange) Large wind farm wake model ( ) ( ) ( ) ( ) < < + = for u for u for u u Intro Te Problems Large Wakes Modelling Results Conclusions

13 Modified to account for presence of turbines Use of turbine geometry as parameter for offset (eigt, diameter) Large wind farm wake model ( ) ( ) ( ) ( ) < < + = = = ,0) / max(,0) max( for u for u for u u radius Intro Te Problems Large Wakes Modelling Results Conclusions

14 Wake recovery

15 Large wind farm wake model Wind speed recovery First approximation for recovery 1.02 relative wind speed wit respect to 1st turbine distance from first turbine [D] Intro Te Problems Large Wakes Modelling Results Conclusions

16 Large wind farm wake model Wind speed recovery Turbines wit more tan 80 D distance are ignored Intro Te Problems Large Wakes Modelling Results Conclusions

17 Large wind farm wake model Wind speed recovery Recovery for a gap between wind turbines Intro Te Problems Large Wakes Modelling Results Conclusions

18 Validation

19 Horns Rev offsore wind farm 1,100 1,000 0,900 0,800 0,700 measured calculated 0,600 0,500 0, row Row average, free wind speed 8 m/s, deg, WF offsore wake model 2008 Intro Te Problems Large Wakes Modelling Results Conclusions

20 Horns Rev offsore wind farm 1,100 1,000 0,900 0,800 0,700 measured calculated 0,600 0,500 0, Turbine by turbine, free wind speed 8 m/s, deg, WF offsore wake model 2008 Intro Te Problems Large Wakes Modelling Results Conclusions

21 Horns Rev offsore wind farm 1,100 1,000 0,900 0,800 0,700 0,600 0,500 0, measured calculated deg, free wind speed 8 m/s, WF wake model 2008 Intro Te Problems Large Wakes Modelling Results Conclusions

22 Horns Rev offsore wind farm 1,100 1,000 0,900 0,800 0,700 0,600 0,500 0, measured calculated deg, free wind speed 8 m/s, WF wake model 2008 Intro Te Problems Large Wakes Modelling Results Conclusions

23 Horns Rev offsore wind farm (7D spacing) 1,1 1,0 relative power 0,9 0,8 0,7 0,6 0,5 0,4 data large wind farm model standard wind farm model turbine number WF 4.0: Turbine by turbine, free wind speed 8 m/s, deg Intro Te Problems Large Wakes Modelling Results Conclusions

24 Nysted offsore wind farm (12 D spacing) relative power 1,1 1,0 0,9 0,8 0,7 0,6 0,5 0,4 data large wind farm model standard wind farm model turbine number WF 4.0: Turbine by turbine, free wind speed 8 m/s, deg Intro Te Problems Large Wakes Modelling Results Conclusions

25 Conclusions Modelling large wind farm wakes is a callenge! We ave very few data points! New Model Properties: Ambient wind speed correction is calculated Considers turbine geometry Considers layout geometry Allows easy modification of wind farm layout Can be used in combination wit classical wake models Computational efficient Accurately models te effect Intro Te Problems Large Wakes Modelling Results Conclusions

26 Acknowledgements Measurements by E2/DONG ENERGY A/S, Leo E. Jensen et.al. Preparation of scenarios by Kurt Hansen, DTU Te work is supported in part by te European Commission under contract #19945 (SES6) UPWIND. Te model (2009) presented is available in GH WindFarmer 4.0

27 Tank you for your attention! Lars Landberg Garrad Hassan and Partners

FLOWSTAR-Energy Validation NoordZee Wind Farm

FLOWSTAR-Energy Validation NoordZee Wind Farm Cambridge Environmental Research Consultants (CERC) Ltd January 26 Introduction FLOWSTAR-Energy 5. NoordZee is an offshore wind farm in Denmark. A FLOWSTAR-Energy