Power curve working group

During the EWEA workshop on the Analysis of Operating Wind Farms (Lyon, France – 2-3 July 2012) it became clear that the impact of ‘non-standard’ inflow conditions on wind turbine power curves is a key issue facing the wind industry today.

A follow up activity of the workshop was the formation of a working group on the impact of ‘non-standard’ inflow conditions on power curves. The working group aims to facilitate stakeholder collaboration in order to acknowledge, address and ultimately resolve this question.

At the EWEA Resource Assessment Technology Workshop (Dublin, 25-26 June 2013) the working group shared the outcomes of this discussion with the wider industry and exchanged information on the efficacy of various power function adjustment models.

The working group was formed by a group of companies with a particular interest in this topic following the Lyon workshop. While EWEA is not actively participating in this working group, EWEA is hosting this information provided below following a request by the working group members.

Working Group Proposals

Inner-Outer Range Proposal (PDF)

Working Group Meetings

Next meeting of the working group:

Date: 16 December  2014
Location: RES Ltd, Glasgow

If you would like to attend this or future meetings or for any questions regarding the Power Curve Working Group, please contact Peter Stuart, RES Ltd: [email protected]

8th meeting of the Power Curve Working Group
6 October 2014


Overview of the Power Curve Working Group Peter Stuart (RES)
Use of Manufacture specific inputs to refine energy yield predictions Taylor Geer (DNV-GL)
Brief update on the of IEC 61400-15 Standard Jason Fields (NREL)
The influence of inflow angle on the power curve Jørgen Højstrup (Højstrup Wind Energy)
Turbulence Intensity measurements offshore for power curve verification and wind resource assessment Rebeca Rivera Lamata & Daniel Pollack (Dong Energy)
Power Curve Modeling in Complex Terrain Using Statistical Models Vera Bulaevskaya, Lawrence Livermore (National Laboratory)
Environmental Influences on Turbine Performance Recent Results Dale Apgar (GE)
Update on the IEC 61400-12-1 Standard Troels Friis Pedersen (DTU)

7th meeting of the Power Curve Working Group
2 September 2014, Kings Langley (near London), UK


Introduction Peter Stuart (RES)
Real-world contractual experience of the inner-outer range Dan Stevens (SSE)
Use of manufacturer specific inputs to refine energy yield predictions Richard Whiting (DNV GL)
Use of nacelle LiDAR data to explore impact of using non-linear averages Chris Slinger (Zephir)
Power performance analysis using LiDAR simple terrain Alex Clerc (RES)
Practical consideration using the Equivalent Power Approach Peder Bay Enevoldsen and Ioannis Antoniou (Siemens)
Calculation of REWS using CFX Paul Hosley (SSE)
Impact of ground boundary on production of short tower turbines – a conceptual study SEE, RWE, RES & DNV GL

6th meeting of the Power Curve Working Group
1 April 2014, DTU Risø Campus, Roskilde, Denmark


Agenda (PDF)
Minutes (PDF)
Introduction (PDF) Peter Stuart (RES)
Validation Analysis – Turbulence Correction (PDF) Alex Clerc (RES)
REWS & TI Correction Methods Vs Real Performance Trends (PDF) Diego Azofra (Barlevento)
A Study of Turbine performance under cold weather driven stable atmospheric conditions in Scandinavia (PDF) Carla Ribeiro (DNV-GL)
Analyses of the mechanisms of amplitude modulation of aero-acoustic wind turbine sound (PDF) Andreas Fischer (DTU)
Steps towards comparison of turbine performance across varying turbine geometries (PDF) Matthew Colls (Prevailing)
Calculating site specific power curve loss estimtates (PDF) Dan Bernadett (AWS Truepower)
Illustrating the Importance of Site Specific Power Curves (PDF) Alan Derrick (RES)
Power curves – Use of spinner anemometry (PDF) Troels Friis Pedersen (DTU)
Rotor Equivalent Wind Speed (PDF) Iñaki Lezaun Mas (GAMESA)
Challenges accompanying the use of the Rotor Equivalent Wind Speed (PDF) I. Antoniou et al (Siemens)
Probabilistic Atmospheric characterization Relevant Shear and Turbulence Intensity statistics (PDF) Mark Kelly (DTU)
Type B Effects (PDF) Erik Tüxen (DNV GL)


5th meeting of the Power Curve Working Group
4 December 2013
, SSE Glasgow, Scotland


Agenda (PDF)
Minutes (PDF)
Validation Framework and Dataset 1 Overview (PDF) Peter Stuart (RES)
Rotor Equivalent Wind Speed – One Power Curve or Two? (PDF) Axel Alberts (Wind Guard)
Turbine Power Performance in different regimes (PDF) Richard Whiting (GL DNV)
PCWG Validation Analysis (PDF) Alex Clerc (RES)
Rotor Equivalent Wind Speed Validation Study (PDF) Jared Kassebaum (EDF RE)
Potential validation dataset (PDF) Daniel Stevens (SSE)
Griffin Power Curve Measurement Campaign (PDF) Ralph Torr (Sgurr)
Proposed Additional RES Dataset (PDF) Peter Stuart (RES)
One year on, A review of Working Group progress to date (PDF) Andrew Tindal (GLGH)
Power Curve Working Group One Year On – REpower Views (PDF) Tomas Blodau (REPower)
Power Curve Working Group: What have we learned and what should our next step be? (PDF) Ioannis Antoniou (Siemens)
Power Curve Working Group – Vestas reflections after year 1 (PDF) Michael Pram Nielsen (Vestas)


4th meeting of the Power Curve Working Group
19 September 2013
, Vestas Aarhus, Denmark


Agenda (PDF)
Minutes (PDF)
Round Robin Results Overview (PDF) Peter Stuart (REpower)
Round Robin Impact of High Wind Shear Introduction (PDF) Anna Marsh (GL DNV)
Round Robin Impact of Turbulence Introduction (PDF) Anabel Gammidge (RWE)
Numerical Modeling (PDF) Peter Stuart (RES)
Extended RR2 Analysis (PDF) Axel Albers (Wind Guard)
The role CFD Modelling (PDF) Oisin Brady (Natural Power)
The role CFD Modelling (PDF) Yavor V. Hristov (Vestas)
The role CFD Modelling (PDF) Richard Whiting (GL DNV)

3rd meeting of the Power Curve Working Group
30 May 2013, REpower Hamburg, Germany


Agenda (PDF)
Minutes (PDF)
Introduction / Welcome (PDF) Tomas Blodau (REpower)
Review of Previous Meetings (PDF) Andrew Tindal (GLGH)
Overview of Round Robin Results (PDF) Peter Stuart (RES Ltd)
Round Robin Exercise 1 Introduction (Shear) (PDF) Anna Marsh (DNV KEMA)
Round Robin Exercise 2 Introduction (Turbulence) (PDF) Anabel Gammidge (RWE)
Review of Inner/Outer Range Proposal (PDF) Tomas Blodau (REpower)
Round Robin Exercise Introduction (Inner/Outer Range) (PDF) Daniel Bendel (REpower)
Power curve measurements using the spinner anemometer (PDF) Jørgen Højstrup (ROMOWind)
Use of LiDARs to measure non-standard flow effect on power curve measurement and resource assessment in the IEA Task 32 (PDF) Rozenn Wagner (DTU Wind Energy)
Round Robin contrast to North American Experience Richard Whiting (GLGH)


2nd meeting of the Power Curve Working Group
12 March 2013,
Remisen Brande, Denmark


Introduction (PDF) – Peter Stuart (RES)

Agenda (PDF)
Minutes (PDF)
Power Curve Working Group Roadmap (PDF)
Siemens Experience of Rotor Average Wind Speed for Power Performance (PDF) Ioannis Antoniou (Siemens Wind Power)
Observed Performance in High Shear and Turbulence (PDF) Daniel Stevens (SSE)
Rotor Equivalent Wind Speed for Power Performance Measurement and AEP Estimate (PDF) Rozenn Wagner (DTU Wind Energy)
Use of 5 Distinct Power Curves as a Function of Shear and Turbulence in Time-Series Energy Capture Calculations (PDF) Dan Bernadett (AWS TruePower)
Integrating Corrections into the Resource Assessment Process (PDF) Andrew Tindal (GLGH)
Experience of Rotor Averaged Power Curve Measurements in Cold Climates (PDF) Alan Derrick (RES)
Using Machine Learning To Create Turbine Performance Models (PDF) Andy Clifton (NREL – National Wind Technology Center)
Dynamic Power Curves and the LLNL Wind Power Program (PDF) Wayne Miller (Lawrence Livermore National Laboratory)
Roadmap for Industry to More Accurately Predict the Performance of Wind Turbines (PDF) Ralph Torr (Sgurr)
10 Measurements as a Basis for Extended use of Standard Power Curves Tomas Blodau (REpower)
Resource Assessment Methods Incorporating Rotor Equivalent Wind Speed, Density and Turbulence on a Time Step Basis (PDF) Anna Marsh (DNV KEMA)
Proposed Round Robin Dataset (PDF) Peter Stuart (RES Ltd)


1st Power Curve Working Group kick-off meeting
4 December 2012, London, UK


Memorandum of Understanding and Minutes (PDF)
Agenda (PDF)
Why are we here? (PDF) Mike Anderson (RES Ltd)
What are the issues? (PDF) Daniel Stevens (SSE)
What are the mechanisms? (PDF) Michael Brower (AWS TruePower)
How to improve yield? (PDF) Andrew Tindal (GLGH)
Influence of Turbine Design Choices (PDF) Tomas Blodau (REpower)
Modelling Impact of Non-Standard Conditions (PDF) Axel Albers (Deutsche Windguard)
Power Curves for Different Ambient Conditions (PDF) Henk-Jan Kooijman (GE)
Experience of Siemens (PDF) Ioannis Antoniou (Siemens Wind Power)
Discussion Points (PDF) Patrick Moriarty (NREL)
The Working Group’s Relationship to IEC (PDF) Alan Derrick (RES Ltd)