Back to the programme printer.gif Print

Delegates are invited to meet and discuss with the poster presenters in this topic directly after the session 'Real world power curves: A new era for wind resource assessments?' taking place on Tuesday, 11 March 2014 at 14:15-15:45. The meet-the-authors will take place in the poster area.

Jan Willem Wagenaar ECN, The Netherlands
Jan Willem Wagenaar (1) F P Koen Boorsma (1) Samuel Davoust (2)
(1) ECN, Petten, The Netherlands (2) Avent Lidar Technology, Orsay, France

Printer friendly version: printer.gif Print

Presenter's biography

Biographies are supplied directly by presenters at EWEA 2014 and are published here unedited

Dr Jan Willem Wagenaar currently is project manager and researcher at ECN Wind Energy. He obtained his master of science at the University of Groningen and his PhD at the University of Nijmegen both in physics. In 2009 he joined ECN and his work focusses on measurements regarding power performance, wind resource assessment and LiDAR in national and international projects. He is coordinator of the MEASNET power performance expert group, work package leader in the project and within ECN coordinator of the R&D line Facilities and Experiments.


"Power performance validation and yaw misalignment the application of nacelle lidar"


To assess the power performance of wind turbines measurements are taken using large, expensive meteorological
masts. Alternatively, wind measurements could be taken from the nacelle anemometry, however, these are highly
influenced by the wake field of the rotor across the nacelle. Nacelle LiDARs offer the possibility to examine the
power performance of wind turbines measuring the undisturbed approaching wind field.

In this work the power performance of modern full scale, near shore turbines is assessed mimicking the offshore
conditions. Not only power curves are determined, but special care is taken for the yaw misalignment, blockage
effect and vertical wind shear.


In order to examine the above two measurement campaigns have started on the ECN test site EWTW, which is a
near shore site consisting of flat, agricultural terrain. The Wind Iris of Avent Lidar Technology is installed on one of
the 2.5MW ECN research turbines. A fully instrumented meteorological mast is nearby including two WindCube
ground based LiDARs.

In addition to that a new prototype of Avent is installed on the XEMC Darwind prototype also present on the test
site. This is a 5MW direct drive turbine with a meteorological mast installed nearby including a Zephir ground
based LiDAR.

Main body of abstract

As indicated two measurement campaigns have started at the ECN test site. The Wind Iris was installed on the
2.5MW research turbine at the end of May and the Avent prototype was installed on the XEMC Darwind prototype
turbine in the beginning of September. Data have been collected and analyses are starting.

From the measured data the power curves will be constructed following as much the IEC standards in resemblance
of work of for instance DTU. In addition the issue of calibration is addressed for the sake of stand-alone operation
and the issue of operating in the wake of another turbine. This for farm operation and turbulence intensity control.
In all cases wind shear effects as measured by ground based LiDARs are taken into account.

A very important aspect is yaw misalignment in the analysis of the turbine yield. It is known that the Wind Iris is
used for calibrating yaw misalignment detection systems. In addition, operational experiences from third parties
indicate yaw misalignment capabilities of the Wind Iris. The measured data are analyzed to verify this using
among others the undisturbed vane measurements from the mast.

Measurements from the Avent prototype are used to measure blockage, or alternatively induction, of the XEMC
Darwind prototype turbine. With this information the best measurement distance for power curve
measurements is sought after and models of the turbine can be verified. It is stressed that it will be the first
time that results of the Avent prototype are shown.


Conclusions will be drawn on power performance validation using nacelle LiDAR and the Wind Iris specifically. This
will include power curves according to the IEC standards and in stand-alone operation, addressing the session
topic: real power curves.

Besides that, but at least as important, conclusions will be drawn on the yaw misalignment capabilities for turbine

Last but not least from the blockage effect of the turbine conclusions will be drawn on the best measurement
distance for power performance and model validation capabilities.

Learning objectives
The objective is that the attendees learn to what extend a nacelle LiDAR, and particularly the Wind Iris, is capable
of validating the power performance of wind turbines. This, with special attention to yaw misalignment, stand-alone
operation, IEC standards and blockage.