1. Monday, 18 May 2015 Stefan Goossens
Field-test of nacelle-based lidar to explore its applications for Vattenfall as wind park operator
Monday, 18 May 2015
Stefan Goossens

2. Introduction

3. Applications
Power curve
Yaw misalignment
Blockage effect

4. Content Measurement campaign Working principle Experience Validation
Power curve
Yaw misalignment
Blockage effect
Financial feasibility
Conclusions and Recommendations
Questions
(Research objective I)
(Research objective II)
(Research objective III)
(Research objective IV)
(Research objective V)

5. Measurement campaign Slufterdam West
Wind Iris installed 18 September 2014
Sodar installed 13 October 2014
Campaign length: 3 months
Photo: Havenbedrijf Rotterdam N.V., Projectorganisatie Maasvlakte 2

6. Working principle

7. Experience Installation ~8 hours by 4 technicians, no major issues
Easy access to data; good availability (90%)
Data processing relatively straightforward
Good support during the campaign from Oldbaum
Plenty of literature and guidelines for comparison and verification

8. Validation Comparison to on-site sodar
Wind Iris is able to measure 10-min wind speed accurately: good correlation, in accordance with literature
Turbulence intensity questionable
YM measurement less accurate than anticipated: 4°vs 0.5°

9. 1. Power curve Wind speed at hub height and 2.5D
Power measurement requires more certainty to be IEC compliant
Density correction
Shear & Veer

10. 2. Yaw misalignment

11. 2. Yaw misalignment
What is the ideal yaw misalignment when it comes to the power curve?
A small angle (~5 degrees)
As close to zero as possible
90 degrees ?

12. 2. Yaw misalignment Mean yaw misalignment: 1.5 degrees
0 degrees yaw misalignment not necessarily best?

13. 2. Yaw misalignment

14. 2. Yaw misalignment
What is the ideal yaw misalignment when it comes to the power curve?
A small angle (~5 degrees)
As close to zero as possible
90 degrees ? ?

15. 3. Blockage effect

16. 3. Blockage effect
Good fit with theory (average and filtered)

17. Financial feasibility

18. Financial feasibility
Strongest drivers of ROI:
Purchase costs
PV improvement factor
Break even point (ROI 0%) for PV improvement of 1.2%
Implementation not recommended due to uncertainty in PV improvement
Financially attractive if power curve improvement can be quantified

19. Conclusions Wind Iris advantages: Wind Iris disadvantages:
Power curve measurement
R&D applications (e.g. blockage)
Wind Iris disadvantages:
Yaw misalignment measurement less accurate than anticipated
No density, shear and veer measurements (yet)

20. Recommendations
Use Wind Iris for PV measurement, R&D and if large yaw misalignment is suspected
More research to investigate effect of yaw misalignment on the PV curve (e.g. intentional YM)
Implementation recommended if PV improvement can be quantified

21. The future
Power curve measurement
Feed-forward control
R&D

22. Questions

23. Research objectives
Gain experience with the installation and operation of the Avent Wind Iris, as well as the collection and analysis of the data, considering that a good dataset is a prerequisite for further analysis.
Determine the power curve based on lidar.
Determine how much Slufterdam West 09 and the park can gain from the installation of a nacelle-based lidar.
(Rotor speed dependent) wind vane calibration.
Determine if other turbines in the park can benefit from the installation of one nacelle-based lidar.
Match yaw misalignment angle, power and wind speed to estimate the power loss due to yaw misalignment.
Estimate the blockage effect/compression zone in front of the turbine and compare to models.
Determine under what conditions a nacelle-based lidar is financially feasible.

24. Power and yaw misalignment

25. Yaw misalignment and RPM/V