2021

10-Year
Assessment

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.

Electricity usage

Zone 2 typically experiences peak electric demand during both the summer and 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 2030. 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 / asset-renewal projects in Zone 2 are listed below – along with their projected year of completion and the factors driving the need for the projects.

The recent installation of inductor banks in the western U.P. have successfully mitigated issues with high voltages during lighter load periods. ATC completed Zone 2 projects that provided new interconnection facilities at Huron and Silver River substations for the new J703 and J704 generation. These new Reciprocating Internal Combustion Engine (RICE) generating plants are important power sources in the U.P. to ensure reliability after the recent retirement of the Presque Isle Power Plant.

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

Zone 2 Planned Projects

Project DescriptionProject #In-service yearNeed driver
Mackinac–McGulpin 138-kV line (9901 and 9903), submarine cable replacement12021Asset Renewal
Atlantic SS, 138/69-kV Bus Reconfiguration and Transformer Addition22022Operational Flexibility
Presque Isle–Tilden 138-kV Line, Loop and Uprate32022Reliability
NLKG31 Tap–Greenstone 138-kV Line, Construct New Transmission Line42022Condition and T-D Interconnection
Tilden SS, Control House Replacement and Breaker & Relay Asset Renewal52023Asset Renewal
J849, Chandler SS Generator Interconnection Facilities and Network Upgrades62023G-T Interconnection
Winona–Atlantic 69kV (Winona69), rebuild82024Reliability

Zone 2 Proposed Projects

Project DescriptionProject #In-service yearNeed driver
Marquette County Reactive Power Project72024Reliability

Zone 2 Provisional Projects

Project DescriptionProject #In-service yearNeed driver
Empire SS, Control House Replacement and Breaker & Relay Asset Renewal92024Asset renewal
Munising Area Reactive Power Project102024Reliability