Southeast Wisconsin
Zone 5
Transmission system limitations in Zone 5
A significant transmission system performance challenge in Zone 5 involves heavy energy market flows through the zone, resulting in potential high post-contingency line loadings.
Electric system overview
Increases expected in population, employment
Population in Zone 5 is projected to grow 0.3 percent annually between now and 2028, and employment is projected to grow 0.9 percent in the same time period. Waukesha County is projected to realize the largest increase in total population and Milwaukee County is projected to realize the largest increase in total employment. Washington County is projected to have the highest annual growth rate in population while Kenosha County is projected to have the highest annual growth rate in employment of 0.6% and 1.7%, respectively.
Electricity usage
Peak electric demand typically occurs during the summer months. Large industrial loads in the Milwaukee metropolitan area are among the largest electricity users in the zone.
Electric load is forecasted to grow approximately 0.7 percent annually through 2029.
Transmission projects in Zone 5
The most notable planned, proposed and provisional network projects and asset-renewal projects in Zone 5, along with their projected year of completion and the factors driving the need for the projects, are listed below.
Zone 5 includes the counties of:
- Kenosha , WI
- Milwaukee , WI
- Ozaukee , WI
- Racine , WI
- Washington , WI
- Waukesha , WI
Zone 5 Planned Projects
| Project Description | Project # | In-service year | Need driver |
|---|---|---|---|
| Mount Pleasant Tech Interconnection Project | 1 | 2019 | T-D interconnection |
| Juneautown SS, new T‑D interconnection rebuild | 2 | 2020 | T-D interconnection |
| State Line SS, new DIC | 3 | 2020 | T-D interconnection |
| Paris–Burlington 138-kV line (8962), rebuild | 4 | 2021 | Condition and performance |
| Port Washington SS–Saukville SS 138-kV line (762), rebuild to a double circuit | 5 | 2021 | Reliability |
| St. Lawrence–Barton–Auburn 138‑kV lines (8032/9752), partial rebuild | 6 | 2021/2022 | Condition and performance |
| Summit–Cooney 138-kV line (6431), rebuild | 7 | 2023 | Condition and performance |
Zone 5 Proposed Projects
| Project Description | Project # | In-service year | Need driver |
|---|---|---|---|
| Arcadian SS, power transformer and control house replacement and asset renewal | 8 | 2023 | Condition and performance |
Zone 5 Provisional Projects
| Project Description | Project # | In-service year | Need driver |
|---|---|---|---|
| None |