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.

ATC’s capital forecast anticipates reinforcements needed to address pending generation retirements such as White Pine. The scope for a transmission project to address White Pine retirements is under review.

Electric system overview

Small increases expected in population, employment Population in Zone 2 is projected to grow about 0.2 percent annually between now and 2025, and employment is expected to grow about 0.9 percent each year in the same time period. Marquette County (Michigan) is projected to realize the largest increase in population and employment. Florence County (Wisconsin) is projected to have the highest growth rate in population while Forest County (Wisconsin) is projected to have the highest growth rate in employment.

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 2026. 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
Munising - Gwinn 69-kV line partial rebuild2017Condition and performance
9 Mile - Detour 69-kV line partial rebuild2017Condition and performance
Pine River - Hiawatha 69-kV line partial rebuild2018Condition and performance
Bay Lake: Benson Lake 138-kV Substation - Installation of SVC2019Low voltages

Zone 2 Proposed Projects

Project DescriptionIn-service yearNeed driver
None

Zone 2 Provisional Projects

Project DescriptionIn-service yearNeed driver
Plains - National 138-kV project2023Overloads and low voltages
Plains 345/138-kV project2023Overloads and low voltages
Plains - Arnold 138-kV upgrade2023Overloads and low voltages
Lakota - Winona 138-kV conversion2021Overloads and low voltages
Winona - Atlantic 69-kV line rebuild2024Overloads and low voltages
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