Task 27 Navigation

Welcome to Task 27 – Work Plan

The two objectives of this extension are is to 1) continue the international Small Wind Association of Testers (SWAT) that will set up peer-reviewed wind turbine testing and evaluation, and 2) develop a new Recommended Practice for Design of Small Wind Turbines in the Built Environment.

The Built Environment

Built-environment Wind Turbines (BWT) can be defined as those turbines installed on the roofs of buildings, side-mounted to a building, integrated into the building design, or operating in the urban setting, see Figure 1.

To develop the recommended practice requires two kinds of activities. First, the built environment wind resource has to be understood properly and second, testing and design standards for BWTs have to be developed.

The expected results are the development of an IEC Design class for BWT, which includes both wind speed requirements and increased level of turbulence intensity. Research and measurements from existing 3-D data sources will be gathered and analyzed to better understand the inflow in the urban and built-environment. Participation in this data collection and analysis task will be undertaken in Australia through Murdoch University, Japan through Nasu-Denki, Sweden through the University of Uppsala, Denmark through RISO data, and Italy under the University of Napoli.

Design Class: Measurements from BWTs will be used to help validate the inflow models with wind speed data and turbulence intensity data. Most countries that participated in the first term of Task 27 are interested in the work of the second term.

Recommended Practice: A BWT Recommended Practice will provide guidelines on turbine testing and design standards. This will add to the existing Consumer label for small wind turbines by providing a label for BWT. The BWT label should also be included in the next edition (fourth) of IEC 61400-2. All experiences coming out from this research task should be used for this future standard in order to reinforce the existing design requirements.

Further areas of research requested by the IEA Wind Task 27 team include identifying other or extreme wind conditions for BWT and developing new stream-lined approaches to understand small wind resource and developing wind assessment methodologies. Interest exists in identifying other wind conditions in Australia, Japan, Spain, the United Kingdom, and the United States. Interest in developing new wind assessment methodologies exists in Australia, Denmark, Ireland, Japan, Spain, the United Kingdom, and the United States. Both of these efforts will help in developing the Recommended Practice on Build-environment Wind Turbines, the final deliverable due at the end of 2013.

Approach and Methodologies
Draft Work Plan
This Task will be addressed in four activities as described below. Note that Activity B is already defined under the Task Proposal – Development and Deployment of Small Wind Turbine Labels for Consumers, dated 15 October 2009.

Work Package 1 SWAT/ Label deployment
Establish the Small Wind Association of Testers (SWAT) as an international labeling organization. Set up the SWAT network for all countries. Other items that need SWAT work include: determination of SWAT governance matters and development of steering committee to start SWAT, development of both a public use website and private members only website; this will be initially handled through Set up annual international SWAT meetings (face-to-face, webinars, etc) international workshops/congress for international members’ experiences exchange, provide a blog, newsgroup.

Work Package 2: Development of built environment wind resource assessment procedure
Evaluate existing 3-D wind data from existing sources. Work through university partners to help get these data analyzed and presented. Develop a targeted wind resource assessment procedure for the urban/built-environment. (Wind conditions found in this urban environment and its affection to wind resources assessment methodology, three dimensional analyses of turbulence and directional variability, wakes, eddies, wind speed profile, etc.)


Find existing 3-D data from the built-environment that can be analyzed. These data can include urban, rooftop, and complex terrain data that can be evaluated for turbulence intensity as well as wind speed/direction.
Start: June 2010                  Finish: March 2011
Deliverable: DL 2.1: Meeting minutes from 2Q10 meeting in Australia

Develop CFD models of the built-environment that have existing high-quality, 3-D data. Look for opportunities to develop models where there are data already collected.
Start: April 2011                  Finish: December 2011
Deliverable: DL 2.2: Summary report of validated built-environment models.

Exercise the models for the wind inflow data collected. Attempt to determine the variability of models versus data and identify how models and data can provide closer correlation.
Start: January 2012                  Finish: September 2012
Deliverable: DL 2.3: Meeting minutes from fall meeting and technical papers presenting modelling and measurement approaches and results.

Develop an approach to estimating the wind inflow based on model/measurement comparisons and insights. Identify ways to correlate wind maps to the micro-siting found in turbines in the built-environment
Start: March 2012                   Finish: November 2012
Deliverable: DL 2.4: Meeting minutes from webinar on this topic.

Develop technical papers on the new approach to understanding the wind inflow seen by small turbines including those in the built environment. Get these papers peer-reviewed and seek critical technical comments.
Start: December 2012         Finish: April 2013
Deliverable: DL 2.5: Meeting minutes from spring meeting 2013

Work Package 3: Development of testing and design standards for built-environment small wind turbines.

Testing in the built environment has to be performed in order to get knowledge for design standards and while there are opportunities to follow the existing IEC standards, the assumption is that testing occurs in a field with clean fetch. Suggested revisions to IEC standards will be made to accommodate the needs of BWT turbines.


Develop protocols for testing built-environment turbines, there must be testing research conducted at a variety of small wind testing institutes. The details of the test protocols and methods shall be shared among small wind testers.
Start: June 2011                  Finish: March 2012
Deliverable: DL 3.1: Meeting minutes from spring 2012, which identifies the international built-environment testing organizations.

Based on initial data collection for turbines and wind inflow, discuss testing details/methodologies and compare results. Look for opportunities to test the same or similar turbines in different built-environments. This activity will take several iterations and will need to be peer-reviewed.
Start: October 2011                  Finish: December 2012
Deliverable: DL 3.2: Meeting minutes from winter virtual meeting 2012

Based on previous data collection activities and comparison between test data and models, identify through a consensus model the best testing approaches for BWTs.
Start: October 2012                  Finish: January 2013
Deliverable: DL 3.3: Technical recommendations for testing urban, built-environment SWT testing.

Define a wind class for design of BWTs including wind speed, wind extremes, turbulence intensity levels, yaw rate extremes and other conditions typical for BWT. This work will be transitioned to 4th edition of writing the IEC 61400-2 standard for inclusion.
Start: March 2013                  Finish: September 2013
Deliverable: DL 3.4: Summary document of Urban/BWT turbine design class and unique load cases.

Work Package 4: Development of consumer labeling for small wind turbines and a Recommended Practice for small turbines in a built-environment

This is the formal objective of the task presented. Activities have been defined to develop a useful IEA Wind Recommended Practice for SWT in the built-environment including specific labeling approaches.


The IEA Consumer Label for Small Wind Turbines as defined in the draft Recommended Practice document, will need to be tried out for BWTs. Once there is data available from BWT testing, the labelling can be tried by different international test organizations. It is likely that the label may need to be modified for turbines in the built-environment.
Start: October 2012                  Finish: December 2013
Deliverable: DL 4.1: Various meeting minutes will highlight new labels for BWTs.

Built-environment wind turbines see different inflow conditions compared to turbines installed on towers in the field. Consequently both design and test organizations need to take different things into account that will frequently occur in the built-environment. Identifying these different items will help make BWTs more reliable.
Start: March 2013         Finish: December 2013
Deliverable: DL 4.2: Recommended Practice for turbines in the built-environment.

Time Schedule with Key Dates

Figure 2. Work Plan Chronogram

Reports, Deliverables, and Dissemination of Results

Table 1. Planned Deliverables and Schedule




Month Due

DL 2.1

Meeting minutes from 2Q10 meeting in Australia



DL 2.2.

Summary report of validated built-environment models



DL 2.3.

Meeting minutes from fall 2012 face-to-face meeting and technical papers presenting modelling and measurement approaches and results



DL 2.4

Meeting minutes from webinar on this topic.




DL 2.5

Meeting minutes from spring face-to-face meeting 2013





Minutes from spring face-to-face meeting 2012, which identifies the international built-environment testing organizations



DL 3.1

Minutes from winter virtual meeting 2012



DL 3.3.

Technical recommendations for testing urban, built-environment SWT testing.



DL 3.4

Summary document of Urban/BWT turbine design class and unique load cases.



DL 4.1

Meeting minutes will highlight new labels for BWTs



DL 4.2

Recommended Practice for turbines in the built-environment




Methods of Review and Evaluation of the Work Progress
Every 6 months, the Operating Agent will consult each project participant on the progress he/she made in comparison to the planning. More frequent consultations may take place in the start-up phase of the Task with the ‘uncertain participants’ in order to check their chance of participation.

The consultations will form a basis for a status report in which the status of the Work Package is summarized in (rough) terms of percentage of completion and estimated time to completion. If necessary the planning is refined. The resulting status report will be included in the 6 month progress reports which will be submitted to the IEA Wind Executive Committee.

A total of 6 milestones are defined. Many of them coincide with the annual face-to-face
meetings. At these meetings the project group will compare the progress and the status of the deliverables with the planning. Depending on the progress and the results achieved, a change in the work programme may be proposed.

The following milestones are of importance:
Milestone 1: Kick-off meeting
Milestone 2: 2nd meeting
Milestone 3: WP2 finished, WP3 begin
Milestone 4: 3rd meeting
Milestone 5: WP3 finished and WP4 begin
Milestone 6: Final meeting WP4 finished

Table 2. Milestones and Schedule




Month Due


Face-to-face Meeting #1 (Kick-off meeting, preliminary establishment of consortium and agreement on work plan, approach and deliverables; Begin WP2)




Final document of new BWT wind resource assessment approach.




Face-to-face Meeting #2 (Discussion of CFD model assumptions; begin drafting WP2 report; begin WP3)




Final document of Urban Small Wind Turbines design class




Face-to-face Meeting #3 (Begin drafting WP3 report; Begin WP4)




Face-to-face Meeting #4 (Begin drafting WP4 report, final report; recommendations and future work)