The overall objective of the Annex was to assist the planning and design of wind farms by facilitating a coordinated effort to develop wind farm models suitable for use in combination with software packages for simulation and analysis of power system stability.
The Annex was started in 2002 and ran through 2007. It was carried out on a cost- and task-shared basis. The participants contributed with financial support to the Operating Agent and carried out activities, supplied information and joined meetings as required to meet the Annex objectives.
Access to detailed reports and database was restricted to the Annex participants.
The effort comprised the following immediate objectives:
- Establishment of an international forum for exchanging knowledge and experience within the field of wind farm modelling for power system studies.
- Development, description and validation of wind farm models. Here, the wind farm models was expected to be developed by the individual participants of the Annex, whereas the description and validation would be coordinated by the Annex as to give the state of the art and to pinpoint key issues for further development.
- Set-up and operation of a common database for benchmark testing of wind turbine and wind farm models as an aid for securing good quality models.
- Denmark: Risø National Laboratory, Poul Sørensen
- Finland: VTT Energy, Bettina Lemstrom
- Ireland: University College Dublin, Alan Mullane and Mark O'Malley
- The Netherlands: ECN and TU Delft, Jan Pierik and J. Morren
- Norway: SINTEF Energy Research, John Olav Tande
- Sweden: Chalmers University of Technology, Ola Carlson
- UK: UMIST, Nick Jenkins and Olimpo Anaya-Lara
- USA: NREL, Sandy Butterfield, Yih-Huei Wan and Eduard Mulijadi
- Portugal, INETI, Ana Estanqueiro
- Dynamic models of wind farms for power system studies - status by IEA Wind R&D Annex 21, Paper presented at EWEC'04, 22 - 25 November 2004, London, UK
- Annex XXI Seminar Presentations, NREL, CO, USA, 11 November 2003
- IEA Wind Task 21, Final Technical Report 2007