North Central Wisconsin
Zone 1

Transmission system characteristics in Zone 1

ATC delivers power in Zone 1 with various transmission facilities including:

  • East-west 345‑kV line from Arpin Substation through Stevens Point extending to the Appleton area,
  • 345‑kV line extending from Wausau to northeastern Minnesota,
  • 345‑kV line extending from Wausau to Stevens Point to eastern Outagamie County (Highway 22),
  • 115‑kV network in the northern portion of the zone, and
  • 138‑kV and 69‑kV network in the southern portion of the zone.

There are a number of transmission system performance issues in Zone 1, including overloaded lines and equipment, and low system voltages.

Transmission system limitations in Zone 1

Key system performance issues from this Assessment in Zone 1 include low voltages and thermal overloads in the southern portion of the zone. These issues will necessitate a combination of reinforcements. In addition, for the northern portion of the zone, 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

Slight increases expected in population, employment – Population in Zone 1 is projected to grow at 0.7 percent annually between now and 2021. Employment is projected to grow at 1.1 percent annually between now and 2021. Marathon County will realize the largest increase in population and employment, while Adams County will have the highest growth rate.

Electricity usage growing – Peak electric demand typically occurs during the summer months, with some winter peaks appearing in the northern portion. Primary electricity users in Zone 1 include a number of large paper mills and food processing plants.

Electric load is projected to grow approximately 0.53 percent annually through 2021.

Transmission projects in Zone 1

We have implemented one network project in Zone 1 since the 2011 Assessment, which was the construction of a new 115‑kV line to the new Woodmin Substation from the Clear Lake Substation.

Our current plans in Zone 1 include 22 system reliability and economic projects between 2012 and 2026, eight of which are related to our new Study-Based Ratings Methodology, described on page 3. These projects are in various stages of development. The most notable planned, proposed, provisional and asset renewal projects in Zone 1, along with their projected year of completion and the factors driving the need for the projects, are listed below.

Zone 1 includes the counties of:
  • Adams , WI
  • Fond du Lac (NW) , WI
  • Forest (SW) , WI
  • Green Lake , WI
  • Juneau , WI
  • Langlade , WI
  • Lincoln , WI
  • Marathon , WI
  • Marquette , WI
  • Monroe (E) , WI
  • Oneida , WI
  • Portage , WI
  • Shawano (W) , WI
  • Vernon (E) , WI
  • Vilas (S) , WI
  • Washara , WI
  • Waupaca , WI
  • Winnebago (W) , WI
  • Wood , WI

Zone 1 Planned Projects

Project DescriptionIn-service yearNeed driver
Monroe County-Council Creek 161‑kV line2014Low voltages, economics, avoid reconfiguration

Zone 1 Provisional Projects

Project DescriptionIn-service yearNeed driver
Fairwater-Mackford Prairie 69-kV line construction2018Overloads and low voltages

Zone 1 Asset Renewal Projects

Project DescriptionIn-service yearNeed driver
Monetello-Wautoma 69-kV line rebuild2017Condition and performance
Plover-Whiting 115-kV line rebuild2019Condition and performance
Coyne-Saratoga 115-kV line partial rebuild2020Condition and performance