Studies and Reports > 2025 Biennial Report > Table of Contents

1.0 Executive Summary

The 2025 Biennial Transmission Projects Report is the thirteenth such report prepared since the requirement to prepare this report was established by the Minnesota Legislature in 2001. Previous Biennial Reports, beginning with the 2005 Report, are available for review on a webpage maintained by the utilities preparing the Report. That webpage is:
http://www.minnelectrans.com

The requirement is found in Minn. Stat. § 216B.2425. That law requires utilities that own or operate electric transmission facilities in the state to report by November 1 of each odd numbered year on the status of the transmission system, including identifying possible solutions to anticipated inadequacies in the transmission system. The Minnesota Transmission Owners (MTO) has consistently defined an "inadequacy" as essentially a situation where the present transmission infrastructure is unable or likely to be unable in the foreseeable future to perform in a consistently reliable fashion and in compliance with regulatory standards.

The Minnesota Public Utilities Commission (Commission or MPUC) established six transmission planning zones across the state in 2003. Those six transmission planning zones are the Northwest Zone, the Northeast Zone, the West Central Zone, the Twin Cities Zone, the Southwest Zone, and the Southeast Zone. Information about transmission facilities in each of the zones is included in the Report.

The 2025 Biennial Report identifies the present and reasonably foreseeable transmission "inadequacies" in the transmission system that exist in each of these six transmission planning zones. Each inadequacy has been assigned a Tracking Number. Information about each inadequacy identified by a Tracking Number is provided. Projects that were identified in earlier reports and assigned a Tracking Number but which have been completed or withdrawn in the past two years are also identified.

Similar to previous reports, this 2025 Biennial Report is a joint effort of the MTO – those utilities that own or operate high voltage transmission lines in the state of Minnesota. These utilities include the following:1

Information about each of the MTO utilities, including their transmission assets in the various zones, is provided in the Report.

As required by Minn. Stat. § 216B.2425, subd. 7, the Biennial Report also provides an update on the status of the utilities' efforts to meet state Renewable Energy Standard (RES) milestones under Minn. Stat. § 216B.1691. In 2023, the Legislature amended Minn. Stat. § 216B.1691 to include carbon-free energy standard (CFS) and additional renewable energy requirements. (Minn. Laws 2023, ch. 7.) Because the Commission has pending dockets on compliance with the CFS, this 2025 Biennial Report includes the status of utilities' efforts to meet the RES standards but does not yet include a gap analysis related to the CFS.

In 2015, the Legislature established a new reporting requirement for certain utilities.2 This reporting requirement is explained in further detail in Chapter 2, subsection 2.6. Pursuant to that requirement, Xcel Energy (currently the only utility to which the requirement applies), has submitted two separate reports entitled (1) Grid Modernization Report and (2) Hosting Capacity Report to the Commission in separate dockets.

In the Commission's June 12, 2018 Order Accepting Report, Granting Variance, and Setting Additional Requirements, the MTO was ordered to include an improved and expanded assessment on non-wire alternatives and a discussion of relevant actions by FERC, MISO, and the Commission related to distributed energy resources and distribution planning. This information can be found in Chapter 2, Sections 2.7 and 2.8.

In the Commission's August 19, 2020 Order Accepting Report, Granting Variance, and Setting Additional Requirements (2020 Order), the MTO was ordered to provide a full discussion and analysis of next steps for identifying gaps between the existing and currently planned transmission system and the transmission system that will be required to meet the companies' publicly stated clean energy goals and to address any need for new or expanded transmission to accommodate:

1. The public clean energy commitments of the MTO member utilities,
2. The requirements in all approved Minnesota resource plans, and
3. Relevant Minnesota statutory goals.

This information was included in Chapter 9 of the 2021 Report but has not been included in the 2025 Report given the intervening changes to the state's carbon-free and renewable energy standards adopted by the 2023 Legislature and the pending CFS compliance dockets.
The 2020 Order also required the MTO to describe its efforts to engage with Midcontinent Independent Transmission System Operator (MISO) to ensure Minnesota's transmission needs have been met and shall provide an assessment on whether MISO has been responsive to Minnesota's identified and likely transmission needs. This information can be found in Chapter 2, Section 2.9.

In the Commission's June 29, 2022 Order Accepting Report, the MTO was ordered to include the information that was required to be filed in the 2021 Report in their 2023 Report as well as the following:

1. Expected sustained HVTL or generation planned outages;
2. Whether those outages are anticipated to have new or incremental congestion; and
3. Whether those outages are anticipated to contribute to sustained incremental congestion. This information is found in Chapter 9.

In the Commission's June 7, 2024 Order Accepting Report, the MTO was ordered to include the information that was required to be filed in the 2023 Report in their 2025 Report as well as the following:

1. An update on the progress and/or performance of the Grid North Partners' proposal for nineteen transmission upgrade projects aimed at enhancing reliability and easing congestion in Minnesota;
2. Information about short-term solutions to increase the robustness of the transmission system they have deployed or plan on deploying along with a report on their performance such as:
   1. dynamic line ratings,
   2. transmission system optimization and reconfigurations,
   3. adjusting transmission conductor limitations to increase line ratings,
   4. increasing substation limiter sizes, and
   5. other grid enhancing technologies that they have deployed or plan on deploying; and
3. Updates to its response to the PUC Information Requests from May 12, 2023.

As enacted by the 2024 Minnesota Legislature,3 Minnesota transmission-owning utilities are submitting the inaugural report on Grid Enhancing Technologies (GETs) with this 2025 Biennial Transmission Plan Report. The 2025 GETs Report identified 30 solutions that will be developed to address congestion in the near-term. This report details historic and future congestion information for Minnesota to identify GETs solutions that meet the Commission's defined payback period. GETs are hardware or software that reduce congestion or enhance the flexibility of the transmission system by increasing the capacity of a transmission line or rerouting electricity from overloaded to uncongested lines, while maintaining industry safety standards. GETs include but are not limited to dynamic line rating, advanced power flow controllers, and topology optimization. The 2025 GETs Report builds upon the 2023 Grid North Partners' study which identified 19 solutions to reduce congestion in the mid-term. The Commission held a hearing in July and issued an order on September 10, 2025, providing additional requirements for the GETs Report. A summary of the 2025 GETs Report and a status update on projects identified in the 2023 Grid North Partners' study is contained in Chapter 9. A full copy of the GETs Report (Nonpublic) is available in Appendix B.

The following is a summary of each subsequent chapter of the 2025 Biennial Report.

Chapter 2 describes the biennial reporting requirements. This includes a discussion of the specific information the MPUC directed the utilities to include in the 2025 Biennial Report. Chapter 8 contains information on clean energy goals.

Chapter 3 is titled Transmission Studies. This chapter includes a table listing a number of studies that have been completed over the past two years. In addition, a number of ongoing regional studies are described in some detail, and several more local, load-serving studies are identified in a separate table. A description of the MISO Transmission Expansion Plan (MTEP) Report is included since most planning is now approved by MISO, and the MTEP Reports show most of the information about the pending projects.

Chapter 4 is the Public Participation chapter. Several recent examples are provided regarding ways utilities have provided opportunities for the general public and local government to learn about and participate in the development of new transmission projects. This chapter summarizes the evolution of MPUC requirements relating to transmission planning and the preparation and submission of the Biennial Report. A section is included describing the webpage the MTO maintains (www.minnelectrans.com) that is available to the public to learn about ongoing transmission projects.

Chapter 5 provides general information about the six Transmission Planning Zones in the state.

Chapter 6 is where all the Transmission Needs are identified. The Report identifies approximately 158 separate transmission inadequacies across the state, including 79 new ones identified in the 2025 Biennial Report.

Each inadequacy is assigned a Tracking Number. The Tracking Number reflects the year the inadequacy was identified and the zone in which it is located. A brief description of each project is provided in the Report, and a reference is provided for each one to where detailed information can be found in the applicable MTEP Report. The 2024 MTEP Report, for example, would be called MTEP24. In addition, information about each project pending, by Tracking Number, is provided. This information addresses alternatives considered, a schedule, and the general impacts on the environment and the area once the project is constructed.
The MTEP Report referenced in the table for each Tracking Number will contain detailed information about the project, including alternatives, costs, and a schedule. Chapter 6 also presents comprehensive instructions on how to find the appropriate MTEP Report containing the desired information. The utilities have also attempted to indicate whether a Certificate of Need (CON) from the Commission might be required for a particular project selected to address a named inadequacy.

Certain projects have been completed since the 2023 Report was filed two years ago or are no longer necessary because of a change in demand or some other factor. These completed or cancelled projects are listed in a table for each zone in Chapter 6.

Chapter 7 focuses on the 14 utilities jointly filing this report. A brief description of each utility and the name and address of a contact person are provided. Information about the number of miles of transmission lines in Minnesota is also provided for each utility.

Chapter 8 provides an analysis of the utilities' progress toward compliance with state RES requirements. Not all utilities that own transmission lines are subject to the state RES, and some utilities that are not required to participate in the Biennial Report must meet the RES milestones. All utilities subject to the RES participated in providing information for this part of the Report.
The utilities subject to the RES have provided a Gap Analysis. A Gap Analysis is an estimate of how many more megawatts of renewable generating capacity a utility will require beyond what is presently available to meet an upcoming RES milestone of a certain percentage of retail sales from renewables. Generally, the Gap Analysis shows that the utilities are in compliance with present standards and expect to have enough generation and transmission to meet RES milestones into the future. Future guidance from the Commission regarding compliance with the CFS may also affect this analysis.

Chapter 9 discusses HVTL or generation planned outages, whether those outages are anticipated to have new or incremental congestion; and whether those outages are anticipated to contribute to sustained incremental congestion. Chapter 9 also provides updates on the MTO's work related to congestion and specifically in response to the Commission's March 24, 2025 Order in Docket No. E999/CI-24-316 that required that the MTOs include a cost-benefit analysis in this Report comparing any feasible battery storage solution to status quo conditions and to its performance under planned grid upgrades at the Nobles County Substation area. Xcel Energy performed the studies to evaluate these solutions and address congestion and limitations on local wind generation under the current operation guide for voltage stability. Xcel Energy's Nobles Grid-Forming Battery Screening System Impact Study determined that the proposed Nobles Battery Storage project with grid forming inverter will provide dynamic voltage stability benefits to the system in dispatches with high wind generation. These benefits are observed when utilizing a grid-forming inverter. Real power dispatch of the battery storage project will need to be managed in order to maximize the voltage stability benefits. Xcel Energy also completed an Nobes Battery Economic Screening Analysis using historical Locational Marginal Prices (LMP) to determine if there would be any economic benefit to adding a 300 MW battery storage unit at the Nobles County substation. Based on this preliminary analysis, it shows that a 300 MW battery storage unit would have a positive impact on curtailments in the area if installed. These studies are provided as Appendices C and D of this Report. Xcel Energy will provide further details in future filings with the Commission.

Chapter 10 includes information on MISO Long Range Transmission Plan (LRTP).

Chapter 11 includes compliance items from MPUC Orders and the Minnesota Legislature.

MPUC Process. Upon receipt of this Report, the Commission will solicit comments from the Department of Commerce, interested parties, and the general public. Any person interested in commenting on the Report or following the comments of others should check the efiling docket for this matter or in some other manner contact the Commission. The Docket Number is E999/M-25-99. The precise schedule for filing comments is established by Minn. Rule Chapter 7848 relating to the biennial reporting process. It is anticipated that the MPUC will make a final decision on the 2025 Biennial Transmission Projects Report in May 2026.