1. Applied Measurement Technologies State-of-the-art case studies Mike Courtney, Kurt Hansen, Rozenn Wagner, Guillaume Léa DTU Wind Energy Carsten Thomsen, Lars Sommer Søndergård Delta

2. DTU Wind Energy, Technical University of Denmark Add Presentation Title in Footer via ”Insert”; ”Header & Footer” Case studies: Wind farm performance validation issues (Kurt) New possibilities with scanning lidars (Mike and Rozenn) Long range windscanner system (Guillaume) Nano-synchronised measurements (eg in wind farms) (Carsten) Nacelle lidars (1G and 2G) for power curve measurements (Rozenn) Danish Wind Industry Annual EventMarch 2014

3. DTU Wind Energy, Technical University of Denmark Add Presentation Title in Footer via ”Insert”; ”Header & Footer” Wind Farm performance validation There is a general lack of knowledge about the flow in and around wind farms. This gives rise to – over-conservative design and – large uncertainties in wind farm performance validation. The problem is exacerbated by increasing park sizes. The only things we can (more or less) rely on are –The power produced by the turbines –The geographical position of the turbines March 2014Danish Wind Industry Annual Event

4. DTU Wind Energy, Technical University of Denmark Add Presentation Title in Footer via ”Insert”; ”Header & Footer” Evaluation of park performance/efficiency – State-of-the-art March 2014 Inflow wind speed: Derived from undisturbed (first row) wind turbine power values with reference to the official power curve; Problem: The power curve is assumed to be representative but this method introduces a large uncertainty because the power curve has been measured under different conditions. Furthermore the spatial distribution of the wind is not included. Inflow wind direction: Derived from an undisturbed wind turbine nacelle position, which is corrected for bias by identifying wake directions between this turbine and the next downstream. Problem: Nacelle position includes yaw misalignment, due to hysteresis in the yawing. Danish Wind Industry Annual Event

5. DTU Wind Energy, Technical University of Denmark Add Presentation Title in Footer via ”Insert”; ”Header & Footer” Inflow conditions for a wind farm – state of art Averaged inflow conditions U,Wdir represents the whole wind farm? March 2014 U,Wdir Almost certainly not! Danish Wind Industry Annual Event

6. DTU Wind Energy, Technical University of Denmark Add Presentation Title in Footer via ”Insert”; ”Header & Footer” Example of park efficiency – used for model evaluation. March 2014 ≈ 66±5% Danish Wind Industry Annual Event

7. DTU Wind Energy, Technical University of Denmark Add Presentation Title in Footer via ”Insert”; ”Header & Footer” New research should be able to Quantify the lateral distribution of inflow wind speed and turbulence; Quantify the spatial distribution of wind speed, turbulence inside the wind farm; Correlate the measured flow conditions to the measured power and loads on turbines in the wind farm; Validate and calibrate park [optimization] models; Improve the wind farm site planning and operation; Formulate new standards for wind farm performance testing. March 2014Danish Wind Industry Annual Event

8. DTU Wind Energy, Technical University of Denmark Add Presentation Title in Footer via ”Insert”; ”Header & Footer” Wind scanners are arriving! – They can contribute to the solutions to many of these research issues. Danish Wind Industry Annual EventMarch 2014

9. DTU Wind Energy, Technical University of Denmark Add Presentation Title in Footer via ”Insert”; ”Header & Footer” Danish Wind Industry Annual EventMarch 2014

10. DTU Wind Energy, Technical University of Denmark Add Presentation Title in Footer via ”Insert”; ”Header & Footer” LANDLAND SEASEA Lidar 1 Lidar 2 U V R2 V R1 Dual doppler scanning Can be used to scan in and around wind farms and terrain features. Can also be used to measure near-shore resource from the land. March 2014Danish Wind Industry Annual Event

11. DTU Wind Energy, Technical University of Denmark Add Presentation Title in Footer via ”Insert”; ”Header & Footer” LANDLAND SEASEA Lidar 1 U U U U Sector scanning with a single scanning lidar If the local flow is reasonably homogeneous, maybe one lidar is enough for resource estimates. But what about turbulence? March 2014Danish Wind Industry Annual Event

12. DTU Wind Energy, Technical University of Denmark Add Presentation Title in Footer via ”Insert”; ”Header & Footer” Danish Wind Industry Annual EventMarch 2014 Easier to try on dry land first ……… Høvsøre metmast

13. DTU Wind Energy, Technical University of Denmark Add Presentation Title in Footer via ”Insert”; ”Header & Footer” Tried different sector widths and scanning speeds Danish Wind Industry Annual EventMarch 2014 A fairly wide sector scanned fairly fast seems to give the best results

14. DTU Wind Energy, Technical University of Denmark Add Presentation Title in Footer via ”Insert”; ”Header & Footer” Sector scanning works – even with wind orthogonal to the sector Danish Wind Industry Annual EventMarch 2014

15. DTU Wind Energy, Technical University of Denmark Add Presentation Title in Footer via ”Insert”; ”Header & Footer” How does the data quality suffer if we scan in different positions? Danish Wind Industry Annual EventMarch 2014 Not too much – we should be able to get a good idea about the spatial variability as well.

16. DTU Wind Energy, Technical University of Denmark Add Presentation Title in Footer via ”Insert”; ”Header & Footer” By how much can scanning lidars reduce the uncertainty of modelled near-shore resource estimates? Is it most cost effective to use one lidar or two (per site)? What does the measurement uncertainty depend on and how big is it? Using the scanning lidar(s), by how much can we reduce the uncertainty of the modelled resource estimate? Are other methods (floating lidar, coastal masts/wind lidars) as good? Danish Wind Industry Annual EventMarch 2014 Project RUNE

17. DTU Wind Energy, Technical University of Denmark Add Presentation Title in Footer via ”Insert”; ”Header & Footer” Good measurements need good time synchronisation Danish Wind Industry Annual EventMarch 2014

18. www.delta.dk An example at Nysted: The 5 km wide oscilloscope

19. www.delta.dk Typical Multi-channel set-up Measuring locations in Nysted Offshore Wind Farm

20. DTU Wind Energy, Technical University of Denmark Add Presentation Title in Footer via ”Insert”; ”Header & Footer” Nacelle lidars for measuring power curves Danish Wind Industry Annual EventMarch 2014

21. DTU Wind Energy, Technical University of Denmark Add Presentation Title in Footer via ”Insert”; ”Header & Footer” Nacelle lidar for power curve measurement EUDP 2010-2013 15° -2 lines of sight -Half opening angles: 15˚ -Gives horizontal wind speed at hub height -Assumes vertical component to be null -Assumes horizontal homogeneity! 2-beam nacelle lidar Avedøre Mast cup anemometer Nacelle lidar Bin-averaged power curves March 2014Danish Wind Industry Annual Event

22. DTU Wind Energy, Technical University of Denmark Add Presentation Title in Footer via ”Insert”; ”Header & Footer” 1.Lidar pre-tilted to account for: - the actual height of the lidar optical head above hub height - the backward tilt of the turbine whilst in operation 2. Extra uncertainty must be added to the wind speed bins for which the measurements took place outside the range hub height +/-2.5%. Measurement height uncertainty Danish Wind Industry Annual Event The measurement height varies due to the nacelle tilting. Nacelle mounted lidar March 2014

23. DTU Wind Energy, Technical University of Denmark Add Presentation Title in Footer via ”Insert”; ”Header & Footer” Lidar calibration Individual calibrations of the two line-of- sight (radial) wind speeds Sonic anemom eter Nacelle lidar Sonic wind speed Lidar radial speed Beam 0 Beam 1 Sonic anemom eter Nacelle lidar Sonic wind speed Lidar radial speed Beam 0 Beam 1 Nacelle mounted lidar The lidar should be calibrated for traceability and uncertainty estimation. March 2014Danish Wind Industry Annual Event

24. DTU Wind Energy, Technical University of Denmark Add Presentation Title in Footer via ”Insert”; ”Header & Footer” Comparison of lidar and cup anemometer 10-minute data Ten minute mean horizontal wind speed Nacelle mounted lidar DONG Energy power station, Avedøre, South West of Copenhagen Very good comparison: 0.3% deviation March 2014Danish Wind Industry Annual Event

25. DTU Wind Energy, Technical University of Denmark Add Presentation Title in Footer via ”Insert”; ”Header & Footer” Comparison of the power curves at 2D Mast top cupLidar AEP for 8m/s100%99.4% Cup anemometer Nacelle lidar Bin-averaged power curvesPower curve uncertainty Very similar power curves and slightly higher uncertainty. Danish Wind Industry Annual Event Nacelle mounted lidar Wagner R, Courtney M. And TF Pedersen., Uncertainty of power curve measurement with a nacelle mounted lidar, Submitted to Wind Energy March 2014

26. DTU Wind Energy, Technical University of Denmark Add Presentation Title in Footer via ”Insert”; ”Header & Footer” Nacelle lidar for power curve measurement EUDP 2010-2013 Output Calibration methodology for two-beam nacelle lidar: Calibrating nacelle lidar, DTU Wind Energy E-0020, http://orbit.dtu.dk/fedora/objects/orbit:123186/datastreams/file_3e428006 -2d25-4a17-96ac-fd9670725a4a/content Power curve measurement with a two-beam nacelle lidar: Wagner R., Pedersen T.F., Courtney M., Antoniou I. Davoust S. and R.L. Rivera; Power curve measurement with a nacelle mounted lidar, Wind Energ. (2013) Online, DOI: 10.1002/we.1643 Procedure for wind turbine power performance measurement with a two- beam nacelle lidar DTU Wind Energy E-0019, http://orbit.dtu.dk/fedora/objects/orbit:120110/datastreams/file_70a241c2- 1138-4f4c-8813-079192c9c04c/content http://orbit.dtu.dk/fedora/objects/orbit:120110/datastreams/file_70a241c2- 1138-4f4c-8813-079192c9c04c/content March 2014Danish Wind Industry Annual Event

27. DTU Wind Energy, Technical University of Denmark Add Presentation Title in Footer via ”Insert”; ”Header & Footer” UniTTe DSF 2014-2017 Unified testing procedures for wind turbines through inflow characterisation using nacelle lidars Objectives  new methodology for power curve and loads assessment based on near-flow measurement, applicable in any type of terrain  Procedures for power curve and loads assessment using profiling nacelle lidars; basis for the future standards March 2014Danish Wind Industry Annual Event

28. DTU Wind Energy, Technical University of Denmark Add Presentation Title in Footer via ”Insert”; ”Header & Footer” Advisory Committee UniTTe Who? “Reviewer” partners “Active” partners Project Coordinator March 2014Danish Wind Industry Annual Event

29. DTU Wind Energy, Technical University of Denmark Add Presentation Title in Footer via ”Insert”; ”Header & Footer” New generation of nacelle lidars able to measure the wind profile in front of the rotor:  Power curve measurement accounting for the shear  Better input for loads assessment UniTTe Novelty 1 March 2014Danish Wind Industry Annual Event

30. DTU Wind Energy, Technical University of Denmark Add Presentation Title in Footer via ”Insert”; ”Header & Footer” Complex terrain Measurement near the rotor:  Assess sensitivity on inflow to terrain effect (CFD and measurements)  Power curve and loads verification based on wind field at 1D  “Correction” from inflow to free flow to correlate the power curve to free wind speed UniTTe Novelty 2 March 2014Danish Wind Industry Annual Event

31. DTU Wind Energy, Technical University of Denmark Add Presentation Title in Footer via ”Insert”; ”Header & Footer” UniTTe Objectives  new methodology for power curve and loads assessment based on near-flow measurement, applicable in any type of terrain  Procedures for power curve and loads assessment using profiling nacelle lidars; basis for the future standards March 2014Danish Wind Industry Annual Event

32. DTU Wind Energy, Technical University of Denmark Add Presentation Title in Footer via ”Insert”; ”Header & Footer” UniTTe 5 technical work packages WP and task numberWP/task name WP1Numerical modelling of the inflow Task 1.1Modelling the blocking effect of the turbine rotor in flat terrain Task 1.2Modelling the impact of the terrain on the wind field close to the rotor Task 1.3Method to retrieve the free wind speed from the near flow field WP2Calibration of profiling nacelle lidars Task 2.1Procedure for the calibration of profiling nacelle lidars Task 2.2Calibration of both lidars to be used in the measurement campaigns Task 2.3In-house factory calibration WP3Measurement campaigns Task 3.1Measurement with scanning lidar on Nordtank turbine in Risø Campus Task 3.2Measurement on turbine on offshore wind turbine (Lillegrund) Task 3.3Measurement on turbine in complex terrain (Vattefall site) Task 3.4Measurement on turbine in complex terrain (RES site) Task 3.5Database management WP4Power curve measurement Task 4.1Evaluation of power curve measurement with profiling nacelle lidars Task 4.2Power curve verification based on near flow wind speed Task 4.3Absolute power curve measurement based on near flow wind speed WP5Reduction of load uncertainties Task 5.1Evaluation of standard loads assessment procedure Task 5.2Loads assessment procedure with a profiling nacelle lidar Task 5.3Loads assessment based on near flow wind speed Task 5.4Derivation of parameters from the nacelle lidar measurements March 2014Danish Wind Industry Annual Event

33. DTU Wind Energy, Technical University of Denmark Add Presentation Title in Footer via ”Insert”; ”Header & Footer” Thanks for your attention – questions? Danish Wind Industry Annual EventMarch 2014 Mike Courtney - mike@dtu.dk