The aim of the MEASNET Power Performance expert group is to a have a high quality of its work, to organize and perform proficiency tests and to achieve a unified understanding of the IEC 61400-12-1 standard. It facilitates the continuous exchange between experts in the field of power performance measurements.

Current Achievements and Decisions

For the individual members of the MEASNET power performance expert group the core task is to perform measurement campaigns in order to determine the power curve of a turbine under test and to calculate the annual energy production (AEP)and its uncertainties. The MEASNET Power Performance expert group has found issues with the measured AEP based upon an inter comparison test. The background and proposed solution are described here. In addition, the expert group has found an issue with the site specific AEP. The background and proposed solution are described here.

Regarding in situ comparison Annex K of the CD2 IEC 61400-12-1 (June 2013) provides two methods to perform such a comparison. The MEASNET Power performance expert group has examined both using a datasets from each individual member and using a common dataset. General conclusions were:

  • Both methods are feasible and applicable to assess the stability of the primary cup anemometer.
  • From the results of the participating institutes it was seen that the wind directional dependent method generally shows a smaller root mean square of the systematic error and statistical error (referred to as δ), although this does not necessarily mean that this method is the preferred one.
  • The wind directional dependent method seems to generate more stable results independently of the considered measurement period.

Work in progress

The MEASNET Power Performance expert group is planned to have a proficiency test in the second half of 2014 including parts from the new standard already.

Furthermore the MEASNET Power Performance expert group is focussing on nacelle anemometry based power curves (IEC 61400-12-2). It has found that this new standard still contains a lot of issues, which are being collected and discussed. This needs to be followed-up.

Status: September 2014