Heather Norton¹, Lindsay Miller² and Marianne Rodgers¹, A decision support process for wind farm repowering using constrained optimization techniques to address uncertainty, Proceedings of 2026 CanREA Operators Summit, Toronto, Canada.

1. Wind Energy Institute of Canada (WEICan)
2. University of Windsor

Abstract

As the wind industry matures, many turbines are poised to reach the end of their design life.  The owners of these turbines have a range of options facing them, which include decommissioning, lifetime extension, and repowering.  The details and expected payback for each option are substantially influenced by site-specific factors such as wind regime and the overall state of the existing turbines[1], such that there is no ‘one size fits all’ solution.  During the planning process for each of the options, more precise estimates of savings and costs are typically obtained over time which may differ substantially from previous values and cast doubt on prior conclusions.  This work reports a process that seeks to provide effective guidance at the very beginning of this journey.  The process is applied to a case study for a real, anonymous wind farm.

Turbine performance decline is first assessed by comparing production estimates from WindPro given historic meteorological conditions with actual recorded production during the same period.  Financial records are then analysed to compute financial performance decline.  Realistic turbine layouts using on-the-market wind turbines are modeled in WindPro to estimate potential energy production of repowering.  The costs of full and partial repowering are estimated based on past projects, openly available information, and conversations with a vendor.  The prior results are then combined into a simple financial model which is used to compute the cost-benefits of each option.  Both a sensitivity analysis and constrained optimization techniques which seek ‘decision boundaries’ between different options are used to communicate how much the input assumptions can change individually or in combination before the recommendations change.

[1]          J. H. Piel, C. Stetter, M. Heumann, M. Westbomke, and M. H. Breitner, “Lifetime Extension, Repowering or Decommissioning? Decision Support for Operators of Ageing Wind Turbines,” J. Phys.: Conf. Ser., vol. 1222, no. 1, p. 012033, May 2019, doi: 10.1088/1742-6596/1222/1/012033.