The MISO Long-Range Transmission Plan (LRTP) is a multi-year multi-phase study to identify a regional transmission network necessary to cost-effectively maintain reliability and serve future needs. Recognizing that transformational changes in the generation fleet require significant changes to the transmission grid to maintain reliability, in 2020 MISO launched the LRTP. Given the magnitude of necessary grid expansion, a multi-year multi-phase effort is necessary given the finite construction labor force and equipment manufacturing capability as well as outage coordination.

The LRTP is one component of MISO’s Reliability Imperative³⁴ – a shared responsibility of electricity providers, states, and MISO to address the urgent and complex challenges facing the electric grid in the MISO region. MISO’s response to the Reliability Imperative consists of a host of initiatives grouped into four categories: Market Redefinition, Transmission Evolution (i.e., LRTP), System Enhancements and Operations of the future.
MISO’s objective of the LRTP is to provide an orderly and timely transmission expansion plan that supports these primary goals:

Reliable System – maintain robust and reliable performance in future conditions with greater uncertainty and variability in supply
Cost Efficient – enable access to lower-cost energy production
Accessible Resources – provide cost-effective solutions allowing the future resource fleet to serve load across the footprint
Flexible Resources – allow more flexibility in the fuel mix for customer choice

MISO evaluates the projects in the LRTP in accordance with MISO’s federally approved tariff. For any project to be deemed needed under MISO’s tariff, it must meet defined criteria. In MISO’s LRTP, MISO and stakeholders worked to identify a transmission plan that simultaneously addresses multiple regional needs – which under the MISO tariff is defined as a Multi-Value Project (MVP). For a project to be deemed needed by MISO as an MVP it must:

Reliability - Address transmission issues to maintain national reliability standards,
Economic - Provide multiple types of economic value across multiple pricing zones with a benefit-to-cost ratio of 1.0 or higher, or
Policy - Support the reliable and economic delivery of energy in support of documented energy policy mandates or laws.

10.2 Tranche 1

In July 2022, MISO approved the first phase or “tranche” of the LRTP. The MISO LRTP Tranche 1 Portfolio consists of 18 transmission projects totaling approximately 2,000 miles of new and upgraded transmission lines, to enhance connectivity and help maintain adequate reliability for the Midwest by 2030 and beyond.

Figure 1 MISO LRTP Tranche 1 Portfolio

(Source: MISO)

The LRTP Tranche 1 includes three projects in Minnesota:

Big Stone South to Alexandria to Big Oaks Transmission Projects: Commission Docket Numbers CN-22-538, TL-23-159, and TL-23-160
Northland Reliability Project: Commission Docket Numbers CN-22-416 and TL- 22-415
Mankato to Mississippi River Project: Commission Docket Numbers CN-22-532 and TL-23-157

MISO LRTP Tranche 1 was intentionally designed as a first-step to address immediate reliability needs driven by retiring fossil fuel plants and to increase primarily intra- but also inter-state transfers. More specifically the MISO LRTP Tranche 1 Portfolio:

Addresses reliability violations as defined by NERC at over 300 different sites across the Midwest. In addition, the portfolio increases transfer capability across the MISO Midwest subregion to allow reliability to be maintained for all hours under varying dispatch patterns driven by differences in weather conditions.
Provides $23.2 billion in net economic savings over the first 20 years of the LRTP Tranche 1 Portfolio’s service, which results in a benefit to cost ratio of at least 2.6. This amount increases to $52.2 billion in net economic savings over 40 years, resulting in a benefit to cost ratio of 3.8.
Supports the reliable interconnection of approximately 43,431 MW in new, primarily renewable, generation capacity across the MISO Midwest subregion – 8,339 MW of which is in Minnesota and the surrounding region.

MISO LRTP Tranche 1 portfolio also was designed to bolster the existing 345kV to position the grid for future LRTP tranches.
A full copy of the MISO LRTP Tranche 1 report is available at: cdn.misoenergy.org/MTEP21 Addendum-LRTP Tranche 1 Report with Executive Summary625790.pdf

10.3 Tranche 2.1

In 2024, MISO approved the next phase of the LRTP (“LRTP Tranche 2.1”) which establishes a new 765kV “backbone” across the Midwest, shown in Figure 2. The LRTP Tranche 2.1 includes 24 projects totaling approximately 3,600 miles of new and upgraded transmission in MISO’s Midwest subregion (Illinois, Indiana, Iowa, Michigan, Minnesota, Missouri, North Dakota, South Dakota, and Wisconsin). The LRTP Tranche 2.1, builds upon, and is enabled by the LRTP Tranche 1.

Figure 2 MISO LRTP Tranche 2.1 Portfolio (Source: MISO)

The LRTP Tranche 2.1 includes the following projects in Minnesota:

Fargo to Alexandria (LRTP#19): Commission Docket Number: CN-25-116
Maple River to Cuyuna (LRTP#20): Commission Docket Number: CN-25-109
Iron Range to Arrowhead (LRTP#21): Commission Docket Number CN-25-111
PowerOn Midwest (LRTP#22, 23, 24, 25): Commission Docket Numbers: CN-25- 117, CN-25-118, CN-25-119, and CN-25-120.
Gopher to Badger Link Project (LRTP#26): Commission Docket Number CN-25- 121

MISO followed an extensive stakeholder process, spending more than 40,000 staff hours, facilitating more than 300 meetings, and capturing feedback to arrive at the LRTP Tranche 2.1 portfolio.³⁵ The LRTP Tranche 2.1 portfolio is needed for:

Reliability: Address reliability violations across the Midwest.³⁶
Economic Efficiency: The $21.8 billion portfolio has a benefit-to-cost ratio of 1.8 to 3.5. This means that every dollar invested in transmission will result in economic benefits of $1.8 to $3.5 dollars. Per MISO’s analysis, the LRTP Tranche 2.1 is expected to provide net economic savings of $23.1 billion to $72.4 billion over the first 20-years of service.³⁷
Policy: Alleviates congestion and enables interconnection of approximately 116,000 GW of primarily carbon-free resources³⁸ to reduce Midwest carbon-dioxide emissions by 127- 199 million metric tons over 20 to 40 years to help states like Minnesota to comply with its decarbonization law.³⁹

A full copy of MISO’s LRTP Tranche 2.1 Portfolio report can be found at:

https://www.misoenergy.org/planning/long-range-transmission-planning/

10.4 Future Tranches

MISO has committed to at least three additional LRTP tranches focused on:

MISO’s Midwest region (includes Minnesota),
MISO’s South region (does not include Minnesota), and
increasing the connection between MISO’s Midwest and South regions.

Per MISO,29 planning of LRTP Midwest and LRTP South (formerly referred to as Tranches 2.2 and 3 (respectively)) is expected to occur in 2026 and 2027, with the LRTP focused on the Midwest and South connection region (formerly referred to as Tranche 4) tentatively expected to occur in 2027 and 2028. Schedule is subject to change based on system needs and priorities.

At the publication of this report, in November 2025, MISO is in the pre-planning stage of LRTP Midwest (Tranche 2.2) which includes refreshing forecasts and assumptions and model development. Issue identification and solution development is expected to begin in 2026. The MTO members are actively engaged in the MISO LRTP Tranche 2.2 process.

MISO’s LRTP is an open and transparent planning process. Additional information on MISO’s LRTP efforts and meetings can be found on MISO’s website: https://www.misoenergy.org/planning/long-range-transmission-planning/

34 Additional information on MISO’s Reliability Imperative available at: https://www.misoenergy.org/meet- miso/MISO_Strategy/reliability-imperative/

35 https://www.misoenergy.org/planning/long-range-transmission-planning/

36 Id. Page 29 Figure 2.19.

37 Id. Page 125 Figure 2.137. Net savings are 20-year NPV in $-2024.

38 Id. Page 75

39 Id. page 142