Small wind turbines are tested at the Lichtenegg Energy Research Park in Austria. Photo credit: © University of Applied Sciences FH Technikum Wien
Small wind turbines are tested at the Lichtenegg Energy Research Park in Austria. Photo credit: © University of Applied Sciences FH Technikum Wien

Distributed Wind Enabling Wind to Contribute to a Distributed Energy Future

Annual Report 2025

Focus Area: The Plant and Grid
Task 41

Authors: Ian Baring-Gould, National Laboratory of the Rockies (NLR), USA; Danielle Preziuso, Pacific Northwest National Laboratory (PNNL), USA; Ruth Baranowski, National Laboratory of the Rockies (NLR), USA

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Objectives

The IEA Wind Task 41 is a group of researchers from 12 member countries dedicated to advancing wind technology as an accessible, cost-effective, and reliable distributed energy resource.

Utilizing distributed energy, including wind energy, can help address rising energy costs, grid reliability, and in some areas while also presenting economic opportunities [1]. Distributed wind also can support rapid power system growth while offering an easy-to-deploy alternative to larger wind projects. Individuals, businesses, farms, and local governments install distributed wind technologies to offset retail power costs or secure long-term power cost certainty, support grid operations and local loads, and electrify remote locations and assets not connected to a centralized grid.

The objective of Task 41 is to coordinate international distributed wind energy research for priority topics that increase the feasibility and visibility of wind technologies as distributed energy resources. In 2025, IEA Wind Task 41 members continued their research efforts to:

  • Inform standards and technical specifications for small, distributed wind turbines
  • Integrate distributed wind into evolving electricity systems with a focus on hybrid power systems
  • Analyze human dimensions of distributed wind through social science research and stakeholder engagement
  • Disseminate information through collaboration, outreach, and socialization of Task 41 work products.

Participation

IEA Wind Task 41 has approximately 40 participants from 12 member countries (Table 1). Republic of Singapore is an active observing country.

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Table 1. IEA Task 41 Participants
Country or Sponsor Member – Institutions/Companies

  • Austria
    Fachhochschule Technikum Wien
  • Belgium
    Vrije Universiteit Brussel
  • Canada
    CORE Renewable Energy Inc; Nergica University of Calgary
  • China
    Inner Mongolia University of Technology
  • Denmark
    Aalborg University; Denmark Technical University; Nordic Folkecenter
  • Greece
    Center for Renewable Energy Sources and Saving (CRES)
  • Ireland
    Dundalk Institute of Technology
  • Italy
    University of Genoa; University of Perugia
  • Republic of Korea
    Korea Institute of Energy Research
  • Spain
    Centro de Investigaciones Energéticas; Medioambientales y Tecnológicas (CIEMAT)
  • United Kingdom
    University of Manchester;
  • United States of America
    National Laboratory of the Rockies Pacific; Northwest National Laboratory

Progress, Results, and Impact in 2025

Task 41 collaboration efforts support research, development, demonstration, and testing of distributed wind technologies. In 2025, Task 41 members conducted research to inform standards and technical specifications for small, distributed wind turbines. Progress in 2025 included:

  • Joint work under Work Packages 1a and 1b on the influence of turbulence on loads and components in support of IEC standards (Figure 1)
  • Utilization of system identification in modeling the yaw response of tail fins for small wind turbines [2]
  • Research on turbulence intensity, spectral characteristics of wind, and wind direction changes in relation to distributed energy [3]
  • The installation of two ground-based ZX300e Light Detection and Ranging units (LiDARs) (a total of 3 LiDARS) in Ireland to focus on wind measurements for distributed wind projects. The researchers are recording wind measurements at 30 heights from 10 m to 100 m to obtain high-resolution wind shear profiles at the Dundalk Institute of Technology campus [4]
  • Improvements to distributed wind modeling, including VAWT and tail-driven yaw in OpenFast [5]
  • Improvements to permanent-magnet design tools to support stator designs and performance assessment tools, including ensemble models for the continental United States (WindWatts)
  • Reporting on agglomerated metrics for small wind: from normalized boundary conditions to atmospheric turbulence
  • Research-quality data collection on a new Bergey Excel 15-kW upwind free, tail-driven yaw turbine
  • Extensive progress in instrumenting two additional turbines, a QED PHX20 20-kW active yaw upwind turbine and an Eocycle M-26 95-kW downwind dampened free yaw turbine that should start producing data in 2026.

 

Task 41 collaboration efforts also support integrating distributed wind into evolving electricity systems. Progress in 2025 included:

  • Developing siting guidelines (to be published in 2026) for distributed wind turbines in Arctic climates
  • Conducting research to support distributed wind energy deployment at a commercial-scale potato production site in Ireland. Based on high-resolution, multi-annual measurements of electricity demand and measurements and modeling of on-site wind and solar resources, researchers concluded that “despite higher capital costs at present, distributed wind energy can be more appropriate for the given energy demand and resource profiles.” [4]

of Task 41 research is to analyze human dimensions of distributed wind through valuation exercises and stakeholder engagement.

 

Perceptions of wind energy technologies vary widely throughout the world and can play a role in determining where and how distributed wind energy systems are deployed. To better understand these perceptions:

  • Task 41 members from Austria expanded their baseline survey work to include perceptions of small wind energy technologies within the country [6]
  • Members in Denmark published a policy brief on the socio-political acceptance of small and distributed wind in the Danish energy transition [7].

Finally, in 2025 work continued on collaboration, outreach, and dissemination of Task 41 work products.

  • Members served as editors of a book published by the Institution of Engineering and Technology titled Distributed Small Wind Turbines [8] and contributed to several chapters related to Task 41 work.
  • In June, members from Italy, the United States, and Belgium presented the Grand Challenges in the wind energy industry and planned research to address some of these challenges at the Wind Energy Science Conference 2025 in Nantes, France.
  • Members in Denmark an open-source distribution network dataset with a large share of distributed wind, Python Library Documentation for an open-source distribution network data with a large share of wind, and a tutorial on using the software wrapper and the dataset (second link below).
  • Also in 2025, members continued compiling regulations shaping requirements and planning processes for installing distributed wind turbines in five Task 41 member countries (Austria, Denmark, Ireland, Italy, and the United States).

Task 41 research publications are available at https://iea-wind.org/task41/t41-publications/and https://iea-wind.org/task41/danish-iea-task-eudp-funded-project-phase-ii/.

Figure 1. A small wind turbine model under testing in the Raffaele Balli Wind Tunnel at the University of Perugia in Italy. Source / Photo credit: Francesco Castellani, University of Perugia
Figure 1. A small wind turbine model under testing in the Raffaele Balli Wind Tunnel at the University of Perugia in Italy. Source / Photo credit: Francesco Castellani, University of Perugia

Highlights from 2025

  • Task 41’s Work Package 1 addresses the characterization, testing, and loads assessment of small wind turbines with a focus on the IEC 46100-2 standard. In 2025, members conducted joint efforts under Work Packages 1a and 1b on the influence of turbulence on loads and components. The goals of the work are to a) better understand the complexity of the problem when approaching the site-suitability analysis for a small distributed wind system; b) analyze the effect of in-flow parameters on the load statistics; c) link flow with loads and fatigue spectra to estimate remaining useful life, and d) investigate the use of surrogate modeling through machine learning approaches in a specific case.

 

  • Members served as editors and contributed chapters to the Institution of Engineering and Technology’s Distributed Small Wind Turbines [8], a book intended for small wind turbine researchers and manufacturers, as well as wind power experts and power grid operators. Members contributed to chapters discussing the context of distributed wind energy, planning and siting, turbulence characteristics, standards, modeling of tail fin dynamics, and sustainable materials.

 

  • Task 41’s Work Package 6 focuses on human-related topics of small wind turbines with a deliverable emphasizing how to include communities to achieve public acceptance. Members investigated aspects of public acceptance in Austria, and their study concluded that a well-chosen location is especially crucial for high acceptance. Their study showed that turbines owned by the municipality in industrial areas are the most accepted, whereas those in the city center are the least accepted (Figure 2 and 3).
Figure 2: Task 41 members investigated aspects of public acceptance of distributed wind turbines in Austria. The most accepted profile (P12) was ownership by the municipality or a non-profit organization with a position in industrial estates and the outskirts of residential areas (left). Source: University of Applied Sciences FH Technikum Wien
Figure 2: Task 41 members investigated aspects of public acceptance of distributed wind turbines in Austria. The most accepted profile (P12) was ownership by the municipality or a non-profit organization with a position in industrial estates and the outskirts of residential areas (left). Source: University of Applied Sciences FH Technikum Wien
Figure 3: The least accepted profile (P6) was ownership by external companies with a position in the city center (right). Source: University of Applied Sciences FH Technikum Wien
Figure 3: The least accepted profile (P6) was ownership by external companies with a position in the city center (right). Source: University of Applied Sciences FH Technikum Wien

Next Steps

Task 41 started in January 2019 and extended for a second phase through 2026. In June 2026, Task 41 members will present findings from their distributed wind energy research at Torque 2026 in Bruges, Belgium. Task members will join an in-person meeting before the Torque 2026 conference to finalize Task 41 work, start drafting Task summary reports, and determine whether there is interest in developing a new task proposal focused on wind in distributed energy systems.

Task Contacts

Ian Baring-Gould, Operating Agent
Ian.Baring-Gould@nlr.gov

Danielle Preziuso, Operating Agent
Danielle.Preziuso@pnnl.gov

Website:
iea-wind.org/task41/

References

[1] McCabe, K., A. Prasanna, J. Lockshin, P. Bhaskar, T. Bowen, R. Baranowski, B. Sigrin, and E. Lantz. (2022). “Distributed Wind Energy Futures Study.” Golden, CO: National Renewable Energy Laboratory.NREL/TP-7A4082519;
nrel.gov/analysis/distributed-wind-futures.html.

[2] Khedr, A. A., Hammam, M. M., Gupta, A., Castellani, F., and Wood, D. H. 2025. Using system identification in modeling the yaw response of tail fins for small wind turbines with bearing friction. Journal of Renewable and Sustainable Energy, 17(2).
https://pubs.aip.org/aip/jrse/article/17/2/023305/3344588/Using-system-identification-in-modeling-the-yaw.

[3] Runacres, M., and I. Mohammad. 2025. Inflow Conditions and Turbulence for Distributed Wind Energy. Vrije Universiteit Brussel, Belgium.
https://usercontent.one/wp/iea-wind.org/wp-content/uploads/2025/12/Task_41_Inflow_Conditions_and_Turbulence_for_Distributed_Wind_062525.pdf.

[4] Byrne, R., P. MacArtain, and G. Reaburn. 2025. A case for supporting distributed wind energy deployment in commercial-scale potato production based on field measurements in Ireland. Cleaner Energy Systems, Volume 10, 2025, 100186, ISSN 2772-7831.
https://www.sciencedirect.com/science/article/pii/S2772783125000184?via%3Dihub.

[5] OpenFAST. National Laboratory of the Rockies.
https://www.nlr.gov/wind/nwtc/openfast.

[6] Flora Bachleitner, Jana Berg, Karthik Subramanya Bhat, Karl Höeferl, Matthias Malottke, Daniel Österreicher, Alex Hirschl. Who, How, and Where? Factors Influencing the Perception of Small-Scale Wind Energy in Austria.
https://usercontent.one/wp/iea-wind.org/wp-content/uploads/2026/01/Factors_Influencing_Perception_Small_WInd_Austria.pdf.

[7] Benefits and Challenges of Small Wind: On Socio-Political Acceptance of Small and Distributed Wind in the Danish Energy Transition. 2025.
https://usercontent.one/wp/iea-wind.org/wp-content/uploads/2025/12/Delivarable-4.1_Policy-brief_final.pdf.

[8] Distributed Small Wind Turbines. 2025.
https://doi.org/10.1049/PBPO267E.