Client: Balfour Beatty Infrastructure Partners LC
POWER Engineers conducted a due diligence of the Hoist hydroelectric station near Negaunee, Michigan. The due diligence was performed as part of an Independent Engineering review on the dam and powerhouse to support the acquisition of the facility and the local utility by an infrastructure investment fund. The due diligence included a conditions assessment, an environmental compliance and FERC licensing review, and OpEx and CapEx assessments.
The facility was built in 1916 on the Dead River, a tributary to Lake Superior, and includes the reservoir, dam, spillway, power intake, tunnel penstock, low-level outlet, and powerhouse. The dam consists of a concrete gravity-arch spillway 440 feet long with a maximum height of 63 feet. The storage basin has an area of about 3,750 acres and a gross capacity of 55,300-acre-feet. The powerhouse contains three Francis-type generating units capable of producing 3.5 MW of power and operating at a head range of approximately 150 feet. Unit 1 is a horizontal-axis machine rated at 1,500 horsepower and is currently retired in place. Units 2 and 3 are vertical-axis machines rated at 2,000 and 2,400 horsepower, respectively.