Duluth Loop
Reliability Project
Under our EnergyForward strategy, we are committed to delivering reliable, affordable and cleaner energy to our customers. We have made significant changes to our generation mix, including the retirement of several small coal units, and now half of the energy we deliver comes from renewable sources. In order to maintain a continuous supply of safe and reliable electricty, we are investing in our transmission infrastructure to enhance the stability of our electric system in the communities we serve.

Announcements
Minnesota Power has filed a combined Certificate of Need and Route Permit Application with the MN Public Utilities Commission (PUC). The MN Department of Commerce-Environmental Energy Environmental Review & Analysis (DOC-EERA) will conduct the environmental review and assessment.
To view the Route Permit docket, visit the eDockets website and follow these simple steps:
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Enter the Docket Number: TL-21-141 into the Docket Number Search Field as shown below.
- Click Search, then on the next screen, click on the documents to view.
To view the Certificate of Need docket, visit the eDockets website and enter the Docket Number: CN-21-140.
Final Proposed Route
Minnesota Power submitted a final proposed route to the MN DOC/MN PUC. This route was developed by considering the purpose and need of the project, reviewing cultural, environmental, and infrastructure data, and by considering comments submitted during our two rounds of public outreach. The proposed route width varies from about 500 feet wide to approximately 1,800-feet wide (250 feet to 900 feet on either side of the centerline for the transmission line). The final right-of-way width needed to operate and maintain the transmission line will vary depending on specific structure type, but will generally range between 100 - 130ft tall.
Structures
The structure types and specifications shown below are preliminary and subject to change. Other structure types may be used depending on final route location.
Typical 115kV Structure
Typical Height: 50-80 feet
Typical Span: 500-1,000 feet
Foundation Type: direct embed
Typical Right-of-Way: 100 feet
Typical 230kV Structure
Typical Height: 60-100 feet
Typical Span: 500-1,000 feet
Foundation Type: direct embed
Typical Right-of-Way: 130 feet
The structure figures shown here are wood pole H-Frame tangent type structures which are anticipated to be common on new lines. Less common structure configurations including but not limited to deadends, angles, crossings, transpositions, and double circuits may also be necessary and may consist of wood pole, guyed wood pole, or steel pole type structures not pictured here. Typical structure heights and spans indicate the average expected values for the majority of structures of this type based on similar facilities. Actual heights and spans are a function of structure type, wire type, wire tension, voltage, route, and topography. Actual span lengths and structure heights may vary outside typical values as necessary.
Schedule
The planning, development and construction schedule is subject to change based on weather, the availability of equipment and materials, the impact of COVID-19 and other potentially unforeseen events.
FAQs
What is the Duluth Loop Reliability Project?
This project will enhance reliability in and around Duluth and along the North Shore by building an additional transmission source. The project includes:
- Construction of a new 115 kilovolt (kV) transmission line between the Ridgeview and Hilltop substations
- Construction of approximately one-mile extension of an existing 230kV transmission line, connecting to the Arrowhead Substation
- Upgrades to the Ridgeview, Hilltop, Haines Road, and Arrowhead substations, including expansion of the Ridgeview and Hilltop substations and reconfiguring existing transmission lines at the Hilltop Substation
By 2025, the new Duluth Loop Reliability Project will be completed and serving our community.
What are the project benefits?
The Duluth Loop Reliability Project will enhance energy reliability for communities in Duluth and the North Shore by adding transmission in the area replace grid strength and stability that was once provided by local coal-fired generation.
Who will benefit from the Duluth Loop Reliability Project?
Many customers within our project Study Area and in communities along the North Shore will directly benefit from the Duluth Loop Reliability Project. This includes many industrial, commercial, and residential customers who will benefit from enhanced reliability provided by this project.
Why is Minnesota Power building a new transmission line?
50% of our energy comes from renewable sources and we will continue to invest in affordable, reliable and increasingly carbon-free sources of energy for the communities we serve.
As part of our clean energy commitment, we’ve reduced our reliance on coal-fired generation. In order to maintain a continuous supply of safe and reliable electricity, we must replace the support those coal plants once supplied to our system. To do this, we’re connecting transmission lines to enhance stability and reliability in our communities.
Where will the new line be located?
The Duluth Loop will be located within the Study Area. Using an integrated routing process collecting data and input to identify the best opportunities to route a new transmission line, we need to identify locations three aspects of the project, including:
- A location for an approximately 14-mile 115 kV line between the Hilltop substation (southern substation) and the Ridgeview substation (north east substation).
- A location for an approximately 1-mile line 230 kV line from the existing line to the Arrowhead substation (south east substation).
- Expansion areas at the Hilltop and Ridgeview substations to provide space for new equipment for the new transmission lines.
What is the timeline of the Project?
We started the early data collection for the project in fall 2020 and anticipate a five-year timeline for route develop through construction including:
- 2021: Routing, public engagement and permitting
- 2022: Permitting and environmental surveys
- 2023 - 2025: Engineering, environmental & land surveys, real estate, construction
- 2025: Project compete
What will the structures look like and how tall will they be?
We are very early in this process. The specific type and size of structures to be used will depend on the routes identified in this process. We anticipate the use of wood pole H-frame structures and steel pole structures similar in appearance to existing transmission lines in the area. For a typical 115kV line H-frame, the structures will range 50 – 80 ft in height, span between 500 to 1000 ft apart and require approximately 100-ft of right-of-way.
Are you planning to install fiber optics on the line?
Preliminary plans are to install fiber optics on new transmission lines. However, this ultimately depends on the final transmission line configurations and whether existing fiber optic infrastructure can be used to meet communication needs.
Why is your public engagement virtual?
The project team is committed to engaging the public with meaningful interactions and conversions while also reducing the spread of COVID-19. Minnesota Power is following state guidelines regarding social distancing and public gatherings.
What is the purpose of holding public meetings?
The purpose of public outreach is for stakeholders and landowners to learn about the project and routing process, ask questions and provide input on routing opportunities and sensitivities. We encourage participation and we hold these public meetings and engagement opportunities to learn more about the Study Area and Study Corridors from the public’s perspective. The timing and need for the public meetings align with the routing process. The project team anticipates holding a second phase of engagement opportunities in March 2020 to gather input on route options.
What does it mean if I live or have property within an alternative route?
Properties within an alternative route may be impacted by the new transmission line. A proposed route has not yet been determined. Minnesota Power will file a proposed route to the Public Utilities Commission for review Summer 2021. The PUC will review and make the final routing decision. Once the route location is determined, Minnesota Power will contact affected landowners along the final route to discuss next steps.
When will Minnesota Power start reaching out to affected landowners for next steps?
Right-of-way acquisition activities occur after a route permit has been approved by the Public Utilities Commission. Minnesota Power plans to identify a proposed route in summer 2021 and submit a route permit application with the PUC shortly after. Affected landowners along the approved final route will be contacted in 2022.
How will right-of-way be maintained after construction?
After initial right-of-way clearing and transmission line construction, additional vegetation management activities may occur. The right-of-way will then need to be cleared once every 6-7 years. Clearing methods will be based upon what is allowed on each individual property.
How does the Minnesota Public Utilities Commission make a decision on the final route?
The Public Utilities Commission’s decision will be based on information provided in Minnesota Power’s route permit application, a document prepared by the Department of Commerce, and a report from a judge that will include testimony from stakeholders. The PUC will review and consider impacts to private properties and natural resources.
Will this project affect wildlife, streams, and recreation areas?
Minnesota Power will do its best to minimize the impacts to wildlife, streams, and recreation areas. The transmission line will need to cross several streams. Minnesota Power may conduct habitat surveys, where necessary. The Minnesota Department of Commerce will perform an environmental review on the entire project.
How close to a residence are you allowed to build a transmission line?
Minnesota Power’s goal is to route the line such that no existing structures will be located within the proposed 100 foot right-of-way, and where practical we will seek to maximum distance to homes to a greater degree. One of the provisions of the easement for the new line will be that no new structures can be built in the right-of-way.
Permitting Process
The Duluth Loop Reliability Project requires two approvals from the MN PUC, a certificate of need and a route permit. The MN PUC will determine whether the Project is needed and, if it is needed, the route for the Project. Over the next 15 months, the MN PUC and MN DOC will be reviewing the Certificate of Need and Route Permit Application, holding public meetings, and developing an Environmental Assessment (EA).
Permitting Documents
Route Permit
- Duluth Loop Route Permit (including Complaint Handling Procedures)
- Duluth Loop Route Permit Map
- MN DOC Rights-of-Way and Easements Factsheet
Duluth Loop Combined Application
- Appendix A: Certificate of Need Application Completeness Checklist
- Appendix B: Route Permit Application Completeness Checklist
- Appendix C: Applicant's Exemption Request
- Appendix D: Applicant's Notice Plan Petition
- Appendix E: Commission Order on Exemption Request and Notice Plan
- Appendix F: 90-day Pre-Application Letter to LGUs and Affidavit
- Appendix G: Notice of Intent to File a Route Permit Application
- Appendix H: Electric and Magnetic Fields Calculations and Noise Calculations
- Appendix I: Duluth Transmission Study
- Appendix J: Detailed Route Maps and Figures
- Appendix K: Technical Drawings of Proposed Structures
- Appendix L: Environmental Impact Tables
- Appendix M: Agency Correspondence
- Appendix N: Public Outreach Materials
- Appendix O: List of Landowners Along and Adjacent to Route Options
- Appendix P: Project Area Substation Load Data and AFR
- Appendix Q: Demand-side Management and Conservation
- Appendix R: Natural Heritage Information System USFWS Species List, Phase la Cultural Resources
- Maps Tab
Route Development
About the project
This project will enhance reliability in and around Duluth and along the North Shore by building an additional transmission source.
The Duluth Loop Reliability Project includes three components:
- Construction of a new 115 kilovolt (kV) transmission line between the Ridgeview and Hilltop substations.
- Construction of approximately one-mile extension of an existing 230kV transmission line, connecting to the Arrowhead substation.
- Upgrades to the Ridgeview, Hilltop, Haines Road, and Arrowhead substations, including expansion of the Ridgeview and Hilltop substations and reconfiguring existing transmission lines at the Hilltop Substation.
Project benefits

Enhance Energy Reliability
The project will enhance energy reliability for communities in Duluth and the North Shore by adding transmission to the area.

Replace Grid Strength and Stability
The project will replace grid strength and stability that was once provided by local coal-fired generation.