modelling the impact of wakes on power output at nysted and horns rev
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Modelling the impact of wakes on power output at Nysted and Horns Rev. R.J. Barthelmie , Indiana University USA/ Risoe DTU DK K. Hansen, DTU Denmark S.T. Frandsen , O. Rathmann , RISOE DTU Denmark G. Schepers ECN, Netherlands K. Rados , NTUA, Greece - PowerPoint PPT PresentationTRANSCRIPT
Modelling the impact of wakes on power output at Nysted and Horns Rev
R.J. Barthelmie, Indiana University USA/Risoe DTU DKK. Hansen, DTU Denmark
S.T. Frandsen, O. Rathmann, RISOE DTU Denmark G. Schepers ECN, Netherlands
K. Rados, NTUA, GreeceW. Schlez, A. Neubert, GH, Germany L.E. Jensen, DONG Energy, DenmarkS. Neckelmann, Vattenfall, Denmark
Funding: NSF CBET-0828655, EU UPWIND # SES6 019945 EU POWWOW #SES6 019898 Data: DONG Energy A/S & Vattenfall AB (Horns Rev), Vattenfall and E. On Sweden
(Nysted)
Modelling wakes in the UpWind projectProblems1. Preliminary analysis of wake
power losses in large offshore wind farms larger than expected. Amended but high uncertainty
2. First v. large wind farms on land
3. Resources and wakes difficult to model in complex terrain
4. Multiple wind farms developed in same area
Solutions1. New parameters and/or next
generation of wake models able to account for ‘deep array’ effect
2. (Assess the magnitude of the issue onshore)
3. Develop, apply and evaluate CFD
4. Assess, develop and evaluate models for whole wind farm modelling
DataIn agreement with data owners some wind farm data have been made availableAccess is open and free (registration necessary)Offshore wake data from
• Vindeby• Middelgrunden• Horns Rev• Nysted (in proc)
Data processed into case studies for Horns Rev, Nysted (performance remains confidential)
Access /registration details:http://mypage.iu.edu/~rbarthel/wakeslab.html
Wake models used in this project
Name Company Type Commercial/ Research
WAsP Risø DTU Engineering CWindfarmer GH Ainslie CRisø Flow Risø DTU Under
developmentR
Wakefarm ECN Parabolised CFD
C/R
CENER Fluent CENER CFD RNS FLow CRES CFD R
NTUA NTUA CFD R
Offshore wind farmsWind farm Nysted Horns Rev
Owner DONG Energy (80%) E.On Sweden (20%)
DONG Energy (40%)Vattenfall (60%)
Turbine number 72 80
Turbine Siemens 2.3 MW Vestas 2 MW
Turbine type Active stall, 2-speed Pitch, variable speed
Rotor diam (D) 82.4 m 80 m
Hub-height 69 m 70 m
Array 8 (E-W) x 9 (N-S) 10 (E-W) x 8 (N-S)
Dist. between turbines
10.3 D (E-W) & 5.8 D (N-S)
7 D (E-W & N-S)
Rated capacity 165.6 MW 160 MW
Annual prod. 595 GWh 600 GWh
Year comm. 2003 2002
Water depth 6-10 m 6-14 m
Distance land 10 km (closest) 14-20 km
http://earthobservatory.nasa.gov/IOTD/view.php?id=3389
7.5 8.0 8.5 9.0 9.5 10.0 10.5 11.0 11.5 12.0 12.5 13.0
Longitude (° E)
54.5
55.0
55.5
56.0
56.5
57.0
57.5
Latitu
de (°
N)
Horns Rev
Nysted
Horns Rev and Nysted layouts
Horns Rev 7D x 7D Nysted 10.5D x 5.8D
Data comparisonData from 2004-2006 Nysted, 2005 Horns RevSelection on:
• wind speed ±0.5 ms-1
• direction ±2.5º • all turbines working in row• all turbines working in
neighbouring rows• two subsequent
observations for stationarity
Gives relatively few observations in each categoryData differences mainly due to spacing?
Model comparison at Horns Rev and Nysted
1 2 3 4 5 6 7 80.2
0.4
0.6
0.8
1
Nor
mal
ised
pow
er
1 2 3 4 5 6 7 80.2
0.4
0.6
0.8
1
Nor
mal
ised
pow
er
263±2.5o
2732.5o
1 2 3 4 5 6 7 80.2
0.4
0.6
0.8
1
Nor
mal
ised
pow
er2832.5o
1 2 3 4 5 6 7 80.2
0 .4
0 .6
0 .8
1
ObservationsW A sPW indfarm erECN
268±2.5o
1 2 3 4 5 6 7 80.2
0.4
0.6
0.8
1
278±2.5o
1 2 3 4 5 6 7 80.2
0 .4
0 .6
0 .8
1
288±2.5o
1 2 3 4 5 6 7 8Turbine
0.2
0.4
0.6
0.8
1
Nor
mal
ised
pow
er
293±2.5o
1 2 3 4 5 6 7 8 9 100.2
0.4
0.6
0.8
1
1.2
Nor
mal
ised
pow
er
1 2 3 4 5 6 7 8 9 100.2
0.4
0.6
0.8
1
Nor
mal
ised
pow
er
255±2.5o
2652 5o
1 2 3 4 5 6 7 8 9 100.2
0.4
0.6
0.8
1
Nor
mal
ised
pow
er
2752 5o
1 2 3 4 5 6 7 8 9 100.2
0.4
0.6
0.8
1
O bservationsW AsPW indfarm erEC NNTUA
260±2.5o
1 2 3 4 5 6 7 8 9 100.2
0.4
0.6
0.8
1
270±2.5o
1 2 3 4 5 6 7 8 9 100.2
0.4
0.6
0.8
1
280±2.5o
1 2 3 4 5 6 7 8 9 10Turb ine
0.2
0.4
0.6
0.8
1
Nor
mal
ised
pow
er
285±2.5o
Model comparison at Horns Rev and NystedExact row, narrow directions
• Seems to be a special case • Agreement on wake
behaviour at Horns Rev and Nysted
• Model agreement within ±10%
Cross row angles• Asymmetry in obs. and
models• Larger uncertainty
ER ER+10º
Model comparison at Horns Rev and NystedConsistency improved in model results High degree of uncertainty• Differences between models• Data issues• Lower wind speeds
Ongoing issues• Asymmetry around central
row• Developing quantitative
methods of evaluation e.g. efficiency
• Stability
Stability at Nysted
0 2 4 6 8Turb ine num ber
0.2
0.4
0.6
0.8
1
1.2
Nor
mal
ised
pow
er o
utpu
t (kW
)
A llS tableU nstableN eutra l
8<U<10 m /s Turbines in row 5 operating0.5 s.d.
.
.Results from Barthelmie et al. European Offshore Wind 2007
-9 -6 -3 0 3 6 9D ista n ce fro m w a ke ce n tre in de g
0.5
0.6
0.7
0.8
0.9
1
Nor
mal
ised
pow
er a
t 2nd
turb
ine
N eutra lS tableU nstab le
Summary and future work• Objective
Reducing uncertainty in predicting power losses from wakes• UpWind project
Provides platform for undertaking model evaluation & data sharing
• Progress madeData analysis and modellingWakes can be modelled with appropriate parameters
• FuturePhysical understanding of wake processes within and downwind wind farms
Other UpWind wake presentations and posters
WIND TURBINE WAKE VIRTUAL LABORATORY: PROPOSAL FOR A NEW COLLABORATION
PO.155 Rebecca Barthelmie, Indiana University, United States & Risø DTU, Denmark
APPLYING FLOW MODELS OF DIFFERENT COMPLEXITY FOR ESTIMATION OF WIND TURBINE WAKES
PO.156 Søren Ott, Risø DTU, Denmark
A FAST PARAMETERIZED WAKE-MODEL FOR LARGE WIND FARMS
PO.161 Ole Steen Rathmann, Risø DTU, Denmark
CFD MODELING ISSUES OF WIND TURBINE WAKES UNDER STABLE ATMOSPHERIC CONDITIONS
PO.163 Evangelos Politis, Centre for Renewable Energy Sources (CRES), Greece
NEW DEVELOPMENTS IN LARGE WIND FARM MODELLING
PO.167 Wolfgang Schlez, Garrad Hassan Deutschland GmbH, Germany
CFD MODELLING OF THE INTERACTION BETWEEN THE SURFACE BOUNDARY LAYER AND ROTOR WAKE
Daniel Cabezón, CENER, Spain