Heritage Sustainable Energy hired Windemuller, Inc., to assist with their $75M Garden Wind project, located in Delta and Schoolcraft counties in Michigan’s Upper Peninsula. Commonwealth designed a new 13-mile-long 138 kV transmission line connecting the Collection System Substation to ATC’s 138 kV transmission system in the Upper Peninsula of Michigan. This line is privately owned by Heritage Sustainable Energy, LLC, and paralleled an existing distribution line owned by Cloverland Electric Cooperative.
The single circuit, wood pole with polymer post insulator line was designed to accommodate up to 111 MVA of electrical output. The phase conductor consisted of 477 kcmil, 24/7 ACSR “Hawk” conductor with one OPGW shield wire communications conductor.
Commonwealth also provided engineering consulting services to design the step-up 34.5/138 kV substation. Commonwealth provided one-lines, three lines, schematics, and wiring diagrams, as well as plan views and elevations. Also, a ground study, grounding design, and details, conduit, cable trench design, and details were performed. Steel and foundations drawings, station service, metering design, protection panel layout and design assistance, and protective relay settings Commonwealth provided. As for documents, Commonwealth provided the bills of material, major equipment specification, construction specification, and close-out documents.