IEA Wind Task 27

Small Wind Turbines in High Turbulence Sites

About Task 27

Duration: 2008-2018

The goal of IEA Wind TCP Task 27 was to understand how turbulence impacts small wind turbine production and whether turbulence is appropriately characterized in the International Electrotechnical Commission (IEC) Standard 61400-2 for small wind turbines.


Task 27 Results

Task 27 worked to develop reasonable criteria for design requirements: vertical velocity, turbulence intensity design levels, replacement of the Normal Turbulence Model (NTM), vibration, and VAWT simplified loads methods.

In 2018, Task 27:

  • Compiled country case studies documenting all CFD modeling, measurements results, and modeling and testing efforts conducted within the scope of Task 27
  • Compiled, discussed, and completed the documentation of technical recommendations for the future IEC 61400-2 standard, fourth revision
  • Finalized the IEA Wind TCP Recommended Practices on micro­-siting of small wind turbines.

These activities were concluded at the end of 2018 and shared with IEC 61400-2 fourth revision experts and other stakeholders.

Task 27 Publications

During the duration of Task 27, members produced the following publications:

Compendium of IEA Wind TCP Task 27 Case Studies
This document highlights and summarizes work from the participating countries related to small wind turbines and turbulence.

Expert Group Report on Recommended Practices: Micro-Siting Small Wind Turbines for Highly Turbulent Sites
This document collects lessons learned from extensive data collection and modeling activities and presents results of research and analysis efforts in the area of micro-siting small wind turbines for highly turbulent sites.

Recommended Practices for Wind Turbine Testing and Evaluation: Consumer Label for Small Wind Turbines
This document describes a method for producing the IEA Wind Consumer Label for Small Wind Turbines. It is an international label, which presents test results based on IEC standards in a condensed and comparable form regardless of where the testing has been conducted.

IEA Wind Task 27 Small Wind Turbine Technical Report Draft
This technical report provides a series of recommendations based on Task 27 research results that should be considered in future standards-making activities for IEC 61400-2. While these recommendations are preliminary in nature and require further validation, many of the results suggest changes to turbulence characteristics, loads models and methods, as well as the development of a new turbine design classification.



Task 27 Participants

Task 27 Observers

Operating Agents

Please contact the Operating Agents with any questions

Ignacio Cruz

Ignacio Cruz

Task 27 Operating Agent

    Trudy Forsyth

    Task 27 Operating Agent

      IEA Task 27 Operating Agent Ignacio Cruz

      Head of Wind Energy Unit
      RES Division
      Department of Energy CIEMAT
      Avda Complutense 40, 28040
      Madrid, SPAIN

      Contact Ignacio Cruz



      IEA Task 27 Operating Agent Trudy Forsyth

      United States

      Contact Trudy Forsyth

      +1 303-949-5363