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Studies and Reports > 2023 Biennial Report >Transmission Planning Zones

Transmission Projects Report 2023
Chapter 9: Outages & Congestion

9.0 Outages & Congestion

9.1   Introduction

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

  • Expected sustained 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.

9.2  System Changes and Upcoming Projects Addressing Congestion Relief

MTO is cognizant of congestion issues, and MTO utilities have taken numerous actions to alleviate congestion throughout the state. MTO utilities’ efforts include the following:

  • NSP System Upgrades: Xcel Energy conducted an internal analysis to determine projects designed to remove system limiters on congested lines in southwest Minnesota. These projects typically addressed substation equipment and sag limits.23
  • Xcel Energy initiated an out-of-cycle request for MISO for completing the second 345 kV circuit from Brookings Co-Lyon Co and Helena-Hampton for the existing CAPX Brookings-TC facility.
  • Market congestion projects including the:
    • Forman 230/115 kV transformer upgrade;
    • High Bridge-Rogers Lake 115 kV line upgrade;
    • Fergus Falls-Morris 115 kV line upgrades;
    • Hoot Lake 115 kV substation upgrades;
    • Canby-Granite Falls 115 kV upgrade;
    • Huntley-Wilmarth 345 kV (Market Efficiency Project);
    • CapX 2020 Brookings 2nd 345 kV addition;
    • CapX 2020 Helena 2nd 345 kV addition;
    • Hoot Lake-Fergus Falls 115 kV upgrades;
    • Morris-Grant County 115 kV upgrades;
    • Franklin-Ft Ridgely-Swan Lake 115 kV upgrades;
    • Swan Lake-Wilmarth 115 kV upgrade;
    • Red Rock-Raptor 115 kV upgrade;
    • Johnson Jct.-Morris 115 kV Ambient Adjusted Rating (AAR);
    • Inman-Elmo-Parkers Prairie-Miltona-Alexandria 115 kV (AAR);
    • Mud Lake-Benton 230 kV (AAR);
    • Wakefield-St. Cloud 115 kV upgrade;
    • Pleasant Valley-Byron 161 kV upgrade;
    • Big Stone-Blair 230 kV upgrade;
    • Coon Creek-Terminal 345 kV upgrade;
    • Coon Creek-Kohlman Lake 345 kV upgrade;
    • Forbes-Iron Range 230 kV (AAR);
    • Blackberry-Riverton 230 kV (AAR).24
  • Transmission System Reconfiguration: Xcel Energy implemented a process to study reconfiguration requests from outside entities. These requests are looked at to determine effectiveness, duration, and impact to the transmission system. Reliability is the primary determinant of whether a reconfiguration request is approved.
  • MTO worked with MISO and other stakeholders to change how ERIS impacts are identified in the MISO DPP process. The current distribution factor (DF) is 20% and the proposal is to reduce the DF to 10% to ensure that more generation is not interconnected without necessary transmission facilities being built to deliver the energy to the system.
  • Xcel Energy initiated two projects, MN Energy Connection and King Connection, which are designed to utilize existing transmission access rights. The MISO interconnection queue has a significant number of new interconnection requests currently seeking to connect to a system that is already very congested. Reusing existing transmission rights through the MN Energy Connection and King Connection Projects allows Xcel Energy to interconnect additional MWs through its existing transmission rights, avoiding long delays often related to MISO queue interconnection studies.
  • Grid North Partners’ Tech Team is working with MTO to identify simple system upgrades (less than $1 million cost) to improve transmission line ratings.
  • MISO LRTP Tranche 1 projects in Minnesota utilize existing 345 kV second circuit capabilities where possible, which will increase the overall ability to transfer power across the system.
  • Xcel Energy initiated an internal study process to determine any transmission system reconfigurations on the underlying transmission system able to have a positive impact on the bulk transmission system and congestion.  Xcel Energy Transmission Operations factor both system reliability, curtailment, and congestion when considering/scheduling transmission outages.
  • Xcel Energy monitors congestion and curtailment on a weekly basis to find new issues as they arise and determine whether a permanent solution is warranted or if the congestion is related to temporary system conditions.
  • GRE is examining factors that have led to increased market congestion, where congestion is occurring, and what can be done to address congestion. GRE is undertaking this congestion effort with the goal of positioning the grid for operational reliability and market efficiency.

These examples represent MTO members’ commitment to actively addressing congestion issues impacting the grid statewide. Going forward, MTO will continue collaborating with other stakeholders to address congestion issues.

9.3  Planned Outages

As part of the 2021 Biennial Plan, the Commission ordered MTO to include a congestion study in future biennial plans. In compliance with the Commission’s directive, MTO prepared the Biennial Transmission Project Report – Congestion Study (attached as Appendix B ). The Congestion Study includes information on the following: (1) expected or 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 or incremental congestion. The Congestion Study analyzed congestion and outages over the next four quarters (Q4 2023 to Q3 2024), comparing market prices and congestion between a benchmark simulation and planned outages simulations using the Control Room Operating Window (CROW). The Congestion Study reveals that there are outages in each quarter that significantly impact average Locational Marginal Prices (LMPs) in the simulations. Additional details can be found in the attached Congestion Study.

9.4  Potential Congestion Based on Future Facility Additions

Notwithstanding the MTO’s efforts described in Section 9.2, MTO believes that there is the potential for continued congestion issues over the next decade. The grid continues to evolve. As detailed in previous sections of this Report, Minnesota (and other states in MISO) is in the midst of transitioning to carbon-free/renewable energy, and the addition of new renewable generation requires additional transmission resources. Efforts to bring new transmission resources are underway; however, the planning, approval, and construction processes take time. For example, in 2022, MISO’s Board of Directors approved Tranche 1 of the LRTP. Tranche 1 includes $10.3 billion in new transmission projects, and it is the first of four tranches designed to provide reliable and economic energy delivery to address future reliability needs.25 While LRTP Tranche 1 encompasses 18 new transmission projects and more than 2,000 miles of transmission lines, the expected in-service dates are not until the 2028-2030 timeframe. Because the availability of these resources is years away, there is the potential for continued congestion issues. MTO continues to look for creative solutions to minimize system congestion while waiting for additional transmission resources to come online.

23 For additional information on MTO utilities’ congestion initiatives, see MTO Response to Commission Staff Information Request No. 4 (May 12, 2023) (eDocket No. 20236-197008-02). In addition to the Commission’s directive to further analyze outages and congestion, Commission Staff also sought information on MTO’s work to alleviate current congestion issues in southwest Minnesota which are resulting in curtailment of certain resources. MTO’s response is public and available on eDockets.