TransAlta to rehab damaged wind farm following tower collapse 

TransAlta Renewables said that it will rehab two wind farms and amend and extend existing power purchase agreements with New Brunswick Power Corp. related to the Kent Hills 1, 2 and 3 facilities, representing a total generating capacity of 167 MW.

The agreements provide for a “blend-and-extend” of the PPAs for an additional 10-years through to December 2045. A TransAlta business unit will move forward with a plan to replace the foundations at Kent Hills 1 and 2 and restore the sites to full operation, which is expected to occur in mid-2023.

The PPAs include a 10% cut to the current contract price until 2033. After that, the contract price aligns with current competitive pricing for wind generation and include escalators intended to reflect inflation. In addition, both parties agreed to work to evaluate the installation of a battery energy storage system at Kent Hills and to consider a potential repowering of Kent Hills at the end of life in 2045.

All 50 turbine foundations at the Kent Hills 1 and 2 sites require replacement, according to a statement released on June 2. A TransAlta business unit, known as KHLP, notified BNY Trust Company of Canada, as trustee, for roughly C$219 million ($173 million) outstanding non-recourse project bonds, secured in part by the Kent Hills 1 and 2 wind sites. The statement said that “events of default may have occurred under the trust indenture governing the terms of the Bonds.” KHLP said it secured an “acceptable waiver of those events of default” and entered into a supplemental indenture that “amends the Bond Indenture and facilitates the rehabilitation” of the Kent Hills 1 and 2 sites.

In October 2021 a tower in phase two of the project collapsed because of what was identified as a bad foundation. TransAlta Renewables said it found deficiencies in the design of all of the wind tower foundations.

The site rehab plan includes dismantling all 49 remaining turbines, demolishing and removing all existing tower foundations, replacing them with newly designed foundations, reassembling the wind turbine towers and generators, replacing the wind turbine that collapsed, and testing each wind turbine generator before returning it to service. KHLP signed contracts with Bird Construction Industrial Services Ltd. and Vestas-Canadian Wind Technology to complete the rehabilitation.

The current estimate of the total rehabilitation expenditures is around C$120 million ($94.95 million), net of insurance proceeds, and inclusive of contingency. Both TransAlta and KHLP said they intend to pursue claims to recover costs and related damages from third parties.

The 167 MW Kent Hills facilities are located near Moncton, in Albert County, New Brunswick and were completed in three phases consisting of 50 turbines at Kent Hills 1 and Kent Hills 2. They achieved commercial operations in December 2008 and November 2010, respectively; and five turbines at Kent Hills 3, which began commercial operations in October 2018. Natural Forces Technologies Inc. owns a 17% interest in respect of each of the Kent Hills 1, 2 and 3 facilities through its ownership interest in KHLP.

As of 2021, the farm consisted of 49 3 MW wind turbines and 5 3.45 MW turbines for a total capacity of 167 MW. The turbines used are Vestas V90-3MW model, which have a rotor diameter of 90 meters (295 ft) and sit on an 80-meter (262 ft) tower.