Wind energy repowering decisions are multifaceted and depend on the physical, political and social landscape, as factors such as noise regulation, aesthetics and political bargaining can significantly influence project development. Policy should recognise that a technology perspective alone cannot inform implementation pathways and should be supplemented with an understanding of the political and social dimensions.
Messages for policy
Wind energy repowering is a negotiated process that involves the increase of clean energy supply as well as the creation of opportunities to reduce community impacts of wind turbines.
Active policy focus on repowering can, with a robust understanding of its multifaceted drivers and decision processes, exploit the opportunities and maximize the potentials and benefits of repowering.
The relevance of policy focus on repowering will increase with time as turbine fleets age, wind energy use increases around the world and the cumulative effects of deployment become more prominent.
Noise regulation, aesthetic principles and political preferences are important drivers in repowering and can lead to earlier and more dismantling of turbines that have impacts on local communities.
Estimations of repowering potentials (for example, net capacity increases) may decrease when considering the breadth of physical, social and economic factors that ultimately drive repowering decisions.
BASED ON L. Kitzing et al. Nature Energy https://doi.org/10.1038/s41560-020-00717-1 (2020).
The policy problem
The combined activity of dismantling or refurbishing existing wind turbines and commissioning new ones (known as repowering) is a growing point of focus for wind energy deployment. Ageing turbine fleets, increasing land-use constraints and the rising relevance of societal factors in siting decisions make the deployment of land-based (onshore) wind energy ever more complicated. To unlock the full potential of wind energy, policies will need to target increasing clean energy supply as well as manage community impacts. Repowering will be an increasingly important element of these policies but it involves complex technical, social and political dynamics. Formulating adequate repowering policy will rely on a robust picture of the extent and potential of repowering activity and of how repowering decisions are made.
Through detailed project-level analysis, our study reveals that wind energy repowering involves consideration of more than just end-of-life replacement and space constraints. Dismantling decisions are multifaceted and result in the dismantling of a larger number of turbines and at an earlier age than physically required. We show this for Denmark, where more than a third (38%) of recent wind energy projects (2012–2019) involved repowering. We found that repowered turbines were dismantled at an average age of 18.6 years — 5.8 years less than those without repowering. Only two thirds (67%) of the capacity dismantled in repowering projects was related to physical space needed for new turbines. This resulted in considerably lower achieved net capacity increases per project, with only 4.72 megawatts commissioned per dismantled megawatt, as compared to 7.05 megawatts if only space-related dismantling were considered. Dismantling reasons besides physical space needs included regulation (noise-related, 8–17% of capacity), development principles (aesthetics, 7–20%), and political bargaining (4–13%). We find that repowering is also a negotiated process between developer and host community, used to reduce community impacts of wind turbines.
We developed a holistic and socially informed approach to analyse repowering activity based on comprehensive project-level information. The approach involves studying repowering projects in their entirety, considering all commissioning and dismantling activity within a project. This includes existing turbines located at the same site as the new development project (on-site) as well as in other locations (off-site) for which the dismantling can be conditionally linked to the new development. We demonstrate the approach for the empirical case of Denmark, the country with the oldest wind energy fleet and highest repowering share. Data were collected from municipal plans, project publications, geospatial analysis and semi-structured interviews with wind energy developers (covering 91% of all dismantled capacity in repowering projects between 2012 and 2019). From this, we identified the full breadth of repowering projects in Denmark and determined multiple dismantling reasons, spanning an array of physical, social and economic dimensions (Fig. 1).
Del Río, P., Calvo Silvosa, A. & Iglesias G¢mez, G. Policies and design elements for the repowering of wind farms: a qualitative analysis of different options. Energy Policy 39, 1897–1908 (2011). This work analyses advantages and drawbacks of policy instruments and design options in repowering of wind farms.
Lacal-Arántegui, R. & Uihlein, A. Repowering wind turbines - analysis of the effects of technology substitution in repowered wind farms. Appl. Energy 23, 660–675 (2020). This work details the change in wind turbine technology and performance that has resulted from historical repowering decisions.
Lantz, E., Leventhal, M. & Baring-Gould, I. Wind Power Project Repowering: Financial Feasibility, Decision Drivers, And Supply Chain Effects Technical Report NREL/TP-6A20-60535 (NREL, 2013); www.nrel.gov/docs/fy14osti/60535.pdfThis work provides background and perspective on the economic drivers for wind energy repowering decisions.
Silvosa, A. C., Gómez, G. I. & Del Río, P. Analyzing the techno-economic determinants for the repowering of Wind Farms. Eng. Econ. 58, 282–303 (2013). This work identifies the relative importance of technical and economic variables in the financial feasibility of repowering wind farm projects.
The original work has been in part funded by the Danish public Energy Technology Development and Demonstration Program (EUDP), project number 64018-0577. The original Article constitutes a contribution from the European Commission to IEA Task 26 research. The views expressed are purely those of the authors and may not in any circumstances be regarded as stating an official position of the European Commission. The original work was authored (in part) by the National Renewable Energy Laboratory, operated by Alliance for Sustainable Energy, LLC, for the US Department of Energy (DOE) under contract no. DE-AC36-08GO28308. Funding provided by the US Department of Energy Office of Energy Efficiency and Renewable Energy Wind Energy Technologies Office. The views expressed in the article do not necessarily represent the views of the DOE or the US government. The US government retains and the publisher, by accepting the article for publication, acknowledges that the US Government retains a nonexclusive, paid-up, irrevocable, worldwide license to publish or reproduce the published form of this work, or allow others to do so, for US government purposes.
The authors declare no competing interests.
About this article
Cite this article
Kitzing, L., Jensen, M.K., Telsnig, T. et al. Multifaceted political and social drivers inform wind energy repowering decisions and potential. Nat Energy 5, 950–951 (2020). https://doi.org/10.1038/s41560-020-00733-1