Michigan’s Upper Peninsula and Northern Wisconsin Zone 2

Transmission system characteristics of Zone 2

ATC delivers power in Zone 2 with various transmission facilities including:

  • Morgan-Plains and Plains-Dead River 345-kV lines,
  • Plains-Stiles 138-kV double-circuit line
  • Lakota Road-Plains 138-kV line, and
  • 138-kV facilities tying the Upper Peninsula of Michigan to the Lower Michigan.
Transmission system limitations in Zone 2

There are a number of transmission system performance issues in Zone 2 including limited ability to import or export power, generator instability, overloaded lines and equipment, low system voltages and chronic limitations to transmission service. Primary drivers of these issues include a mismatch of load to generation in the Upper Peninsula and aging facilities in poor condition. In addition, other ongoing studies, including Northern Area Studies performed by ATC and MISO, have identified several voltage and thermal limitations. The most severe limitations occur during both peak and off-peak periods.

While not specifically identified in the project list for this assessment, ATC’s capital forecast anticipates reinforcements  needed to address pending generation retirements such as White Pine. The scope for a project to address White Pine retirements is under review. It might include conversion of the 69‑kV facilities between the Conover Substation in northern Wisconsin and the Winona Substation in Michigan to 138‑kV operation.

Electric system overview

Small increases expected in population, employment – Population in Zone 2 is projected to grow about 0.3 percent annually between now and 2024, and employment is expected to grow about 0.9 percent each year in the same time period. Marquette County, Mich. is projected to realize the largest increase in both employment and growth rate.

Electricity usage growing

Zone 2 typically experiences peak electric demand during the winter months. Ore mining and paper mills are the largest electricity users in the zone.

Electric load is forecasted to increase by 0.3 percent annually through 2025. Also, locally generated electricity is declining in the area with smaller, coal‑fired generators most at risk. This includes generation owned by industry, municipalities and utilities.

Transmission projects in Zone 2

The most notable planned, proposed and provisional network projects and asset renewal projects in Zone 2, along with their projected year of completion and the factors driving the need for the projects, are listed below.

Zone 2 includes the counties of:
  • Alger, MI
  • Baraga, MI
  • Chippewa, MI
  • Delta, MI
  • Dickinson, MI
  • Florence, WI
  • Forest (N), WI
  • Gogebic (E), MI
  • Houghton, MI
  • Iron, MI
  • Keweenaw, MI
  • Luce, MI
  • Mackinac, MI
  • Marinette (N), WI
  • Marquette, MI
  • Menonminee (N), MI
  • Ontonagon (E), MI
  • Schoolcraft, MI
  • Vilas (N), WI

Zone 2 Planned Projects

Project DescriptionIn-service yearNeed driver
Bay Lake: Holmes-Old Mead Road 138-kV project2016Overloads and low voltages
Bay Lake: Benson Lake 138-kV Substation-Installation of SVC2019Overloads and low voltages
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Zone 2 Provisional Projects

Project DescriptionIn-service yearNeed driver
Plains-National 138-kV project2020Overloads, low voltages
Plains 345/138-kV project2020Overloads, low voltages
Plains-Arnold 138-kV upgrade2020Overloads, low voltages
Winona-Atlantic 69-kV line rebuild2022Overloads, low voltages

Zone 2 Asset Renewal Projects

Project DescriptionIn-service yearNeed driver
Pine River-Hiawatha 69-kV line partial rebuild2018Condition and performance
Munising-Gwinn 69-kV line partial rebuild2018Condition and performance
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