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
  • Conover-Plains 138-kV line, and
  • 138-kV facilities tying the Upper Peninsula of Michigan to the Lower Peninsula.

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 or obsolete condition.

Transmission system limitations in Zone 2

In the analysis of Zone 2, we identified low voltages, high voltages, transmission facility overloads and transmission service limitations. In addition, other studies occurring in parallel with this Assessment, including Northern Area Studies performed by ATC and MISO, have identified several voltage and thermal limitations. The most severe limitations occur during off‑peak periods.

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 2021, and employment is expected to grow about 1.0 percent each year in the same time period. Marquette County, Mich., is projected to realize the largest increase in employment, while Houghton County is projected to have the highest 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 projected to increase by 0.35 percent annually through 2021. 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

We have implemented three network projects in Zone 2 since the 2011 Assessment, including installing a second 138/69‑kV transformer and a 138‑kV ring bus at the Chandler Substation.

Our current plans in Zone 2 include 20 system reliability and economic projects between 2012 and 2026, three of which are related to our new Study-Based Rating Methodology. These projects are in various stages of development. The most notable planned, proposed, provisional 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.

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
Atlantic-M38 69-kV line rebuild2013Overloads, low voltages, condition and performance
Straits-Pine River 69‑kV double circuit rebuild2014Overloads and low voltages
Mackinac 138‑kV Substation;
Installation of back-to-back HVDC flow control device
2014Address/control flow across eastern U.P., overloads and low voltages

Zone 2 Proposed Projects

Project DescriptionIn-service yearNeed driver
Chandler-Old Mead Road 138‑kV double circuit lines2014Overloads and low voltages
Arnold 345‑kV Substation construction and 345/138‑kV transformer2014Overloads and low voltages
Bay Lake: Green Bay-Morgan-Plains-National
345‑kV line construction
2016-2018Overloads and low voltages
Bay Lake: Holmes-Escanaba 138‑kV project2016-2018Overloads and low voltages

Zone 2 Provisional Projects

Project DescriptionIn-service yearNeed driver
Seney-Blaney Park 69‑kV line uprate2015Overloads, low voltages, condition and performance

Zone 2 Asset Renewal Projects

Project DescriptionIn-service yearNeed driver
Nine Mile-Roberts 69-kV line partial rebuild2012Condition and performance
Munising-Gwinn 69-kV line partial rebuild2012-2013Condition and performance
Rexton-Hiawatha 69-kV line partial rebuild2015Condition and performance
Conover-Mass 69-kV line partial rebuild2018Condition and performance
Powers-Chalk Hill 69-kV line partial rebuild2018Condition and performance
Straits-McGulpin 138-kV submarine cable replacements2020Condition and performance