Wisconsin Electric Power Co. told the Public Service Commission of Wisconsin in an Oct. 31 quarterly update that a new hydroelectric facility at the site of its existing Twin Falls Hydroelectric Project in the Town of Florence, Florence County, Wisconsin, and the Town of Breitung, Dickinson County, Michigan, is largely complete.
The commission had approved the project in May 2013. The utility said that commercial operation began on July 29, 2016. The closure dam construction started on July 29, 2016, and is approximately 65% complete. Planning for the demolition of the old powerhouse has started, with plans to issue a contract in the fourth quarter with demolition starting in the second quarter of 2017.
The final design is to be completed in three phases:
- Phase 1 covers the upgrades to the access road, upstream and downstream cofferdam construction for new powerhouse, and excavation for new powerhouse (Engineering Complete);
- Phase 2 covers design of the new powerhouse and Wisconsin Spillway. This design package was approved by the Federal Regulatory Commission.(Engineering Complete); and
- Phase 3 covers the design of the Michigan Closure Dam and demolition of the existing powerhouse, which was approved by FERC (Engineering Complete).
Black & Veatch is the engineer of record. 17 of 17 planned procurements are under contract. All contract equipment has been delivered. The startup and commissioning of in-place equipment is complete. Contract closeout continues. Project closeout is scheduled for 2017
The total estimated project cost is $72,300,000, with $65,139,025 of that spent so far.
The Twin Falls Hydroelectric Facility was constructed and placed in service in 1912 by a WEPCO predecessor company. Most of the powerhouse equipment, including the turbines, were installed between 1912 and 1915, and are in relatively poor physical condition due to age and deterioration. WEPCO decided that the most cost-effective approach to address these issues is to construct a new powerhouse and remove, rather than repair the existing powerhouse.
The rehabbed project is expected to generate approximately 43,600 MWh per year. The total installed capacity would be increased from 6.1 MW to approximately 9 MW. The new powerhouse contains two 4.5-MW identical Kaplan vertical-type turbines.