Repowering Legacy Wind Farms for the 2020s and Beyond

Sargent & Lundy performed independent engineering reviews and analyses of 13 partially repowered wind power projects in 2017


Repowering Legacy Wind Farms for the 2020s and Beyond
Texas and Midwest
Client: Thirteen wind farms in two states


Project Highlights:

  • Plant Type: Wind Power Projects
  • Size: More than 1,900 MW (total)

Project Description:

Sargent & Lundy performed confidential independent engineering reviews of 12 wind farms in Texas that are being partially repowered, as well as one project in the Midwest that may be repowered. A partial repowering involves installing longer blades on a site’s original wind turbines and upgrading certain internal components and the control system. Partial repowering allows aging wind turbines to achieve improved performance and increased capacity and to qualify for additional production tax credits while utilizing a wind farm’s original turbine foundations and towers.

The wind energy projects’ owners and tax equity investors engaged Sargent & Lundy to perform extensive engineering inspections and analyses of the existing foundations and towers to assess whether the equipment is capable of meeting lifetime extension operational requirements, including those for extended fatigue lives. The clients engaged Sargent & Lundy because of our overall strong wind power capabilities, industry-leading wind turbine foundation experience, and overall depth and breadth of engineering capabilities, particularly our capabilities regarding rotating equipment foundation analysis and structural engineering.

Sargent & Lundy also evaluated other aspects of the repowered wind farms, including plant performance, electrical balance-of-plant systems, contracts, permits, operations and maintenance (O&M) budgets, and other items. As part of our review, Sargent & Lundy project team personnel performed extensive on-site project walk-down inspections and numerous wind turbine climbs. Contracts reviewed include power purchase agreements (PPAs), interconnection agreements, and O&M agreements.


Project Scope:

  • Independent engineering analysis of existing wind turbine foundations, towers, and balance-of-plant electrical systems
  • Inspections and observations of installed wind turbine foundations, towers, and electrical facilities
  • Assessment of the impact of repowering wind turbines on plant performance, O&M expenses, contractual obligations, and permits
  • Provide independent engineering reports and advice to support investments in the repowered projects

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