Michigan’s Upper Peninsula and Northern Wisconsin Zone 2

Transmission system limitations in Zone 2

There are several potential transmission system performance issues in Zone 2, including limited ability to import or export power, potential generator instability, and low and high system voltages.  Potential overloads that are a result of multiple contingency planning events will continue to be monitored. The most severe limitations are expected to occur during both peak and off‑peak periods.

Electric system overview

Small increases expected in population, employment – Population in Zone 2 is projected to remain constant between now and 2028, and employment is expected to grow about 0.4 percent each year in the same time period. Marquette County (Michigan) is projected to realize the largest total increase in population and employment and is projected to have the highest annual growth rate in population while Keweenaw County (Michigan) is projected to have the highest annual growth rate in employment.

Electricity usage

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 0.2 percent annually through 2029. 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.

The Munising‑Blaney Park 69‑kV line (Inland) rebuild, which was initiated due to condition and performance and was recently completed, will provide a significant reliability benefit to customers including Alger-Delta and UPPCo.  Previous poor reliability and extended outages on this line will be improved.

ATC completed Zone 2 projects that provided new interconnection facilities at Huron and Silver River substations for the new J703 and J704, respectively, generation.  These new Reciprocating Internal Combustion Engine (RICE) generating plants are important power sources in the U.P. to ensure reliability subsequent to the recent retirement of the Presque Isle power plant.

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 DescriptionProject #In-service yearNeed driver
M-38 SS, new 138-kV inductor bank12019Reliability
Silver River SS, new 138-kV inductor bank22019Reliability
Hiawatha - Pine River 69-kV line (ESE_6908), replace select poles, cross arms32020Condition and performance
Mackinac - McGulpin 138-kV line (9901 and 9903), submarine cable replacement42021Condition and performance

Zone 2 Proposed Projects

Project DescriptionProject #In-service yearNeed driver
Atlantic SS, 138/69 kV bus reconfiguration and transformer addition52022Operational flexibility
NLKG31 Tap - Greenstone 138-kV line, construct new transmission line62022Condition and T-D interconnection
Presque Isle - Tilden 138-kV line, loop and uprate72022Reliability

Zone 2 Provisional Projects

Project DescriptionProject #In-service yearNeed driver
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