TransAlta to rehab damaged wind farm following tower collapse

Kent Hills wind farm, New Brunswick, Canada

TransAlta Renewables announced that it will refurbish two wind farms and amend existing power purchase agreements with New Brunswick Power Corp. relating to the Kent Hills 1 and 3 facilities. These have a combined generating capacity of 167MW.  

The agreements provide for a “blend-and-extend” of the PPAs for an additional 10-years through to December 2045. TransAlta will move forward with a plan for Kent Hills 1 & 2 to be rebuilt and fully operational. This is expected in mid-2023.

The PPAs provide a 10% reduction in the contract price up to 2033. After that, the contract price is aligned with current competitive pricing for wind generator and includes inflation-adjustable escalators. Both parties also agreed to cooperate in evaluating the installation of a battery storage system at Kent Hills, and to examine a possible repowering at Kent Hills at the end-of-life in 2045.  

According to a statement issued on June 2, all 50 turbine foundations at Kent Hills 1 and 2 sites need replacement. TransAlta’s business unit known as KHLP notified BNY Trust Company of Canada as trustee for approximately C$219 million ($173million) of outstanding non-recourse project bonds. These bonds were secured in part by the Kent Hills 2 and 1 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.

A poor foundation caused the collapse in October 2021 of a phase 2 tower. TransAlta Renewables claimed that all foundations of wind towers were flawed.

The site rehabilitation plan involves dismantling all 49 turbines, demolishing and removing all tower foundations, replacing them by new foundations, reassembling wind turbine towers and generators, and testing each wind generator before it is returned to service. KHLP has signed contracts with Vestas-Canadian Wind Technology and Bird Construction Industrial Services Ltd. to complete the rehabilitation.

The current estimated total rehabilitation expenses are C$120million ($94.95million), net insurance proceeds and inclusive of contingency. TransAlta, and KHLP both stated they will pursue claims from third parties to recover costs as well as related damages.

The 167 MW Kent Hills facilities were built near Moncton in Albert County in New Brunswick. They were completed in three phases, with 50 turbines at Kent Hills 1, and Kent Hills 2. They went into commercial operation in December 2008, and November 2010, respectively. Five turbines at Kent Hills 3 were also commercially operational. Commercial operations began in October 2018. Natural Forces Technologies Inc. has a 17% stake in each of Kent Hills 1, 2 & 3 facilities. This is through its ownership interest at KHLP.    

The farm contained 49 3MW wind turbines, and 5 3.45MW turbines, totaling 167 MW. Vestas V90-3MW turbines were used. They have a rotor diameter 90 meters (295ft) and are mounted on a tower 80 meters (262ft).