Midcontinent Grid Operator Announces Approval of $30 Billion Transmission Expansion Plan

The Midcontinent Independent System Operator (MISO) Board of Directors on Dec. 12 approved the 2024 MISO Transmission Expansion Plan, a grid expansion plan with a portfolio consisting of 488 transmission projects totaling $30 billion. The projects cover 5,000 miles of transmission lines across 15 states and aim to strengthen grid reliability in the face of extreme weather and increasing electricity demand.

Apart from local reliability and growth projects, the plan includes the Long Range Transmission Planning, or LRTP, Tranche 2.1 portfolio, and the Joint Targeted Interconnection Queue, JTIQ, projects with Southwest Power Pool. The highly anticipated LRTP Tranche 2.1 Portfolio creates a ground-breaking transmission backbone while delivering benefits that exceed costs.

The $21.8 billion LRTP Tranche 2.1 portfolio consists of 24 projects spanning the states of Illinois, Indiana, Iowa, Michigan, Minnesota, Missouri, North Dakota, South Dakota, and Wisconsin. The portfolio provides a benefit-to-cost ratio between 1.8-3.5, with benefits potentially surpassing $72 billion. The benefits are based on metrics, such as reliability, reduced risk from extreme weather, avoided capacity costs, energy savings from reduced losses, and reduced transmission outage costs. This portfolio benefits the Western MISO region by creating export outlets for North Dakota and South Dakota and improves transfer capacity through Minnesota, Wisconsin, and Iowa. In the Central MISO region, Tranche 2.1 establishes a strong 765 kV transmission path and enables a bidirectional transfer of electricity between the East and West.

The plan will invest $6.7 billion in 459 local grid reliability projects with a combined 932 miles of transmission lines across 15 states in the MISO region. Looking at the geographical distribution of the investment, the four states of Indiana, Michigan, Minnesota, Texas, and Wisconsin received the highest investment with over $800 million allocated for each state.

The $1.6 billion JTIQ portfolio consists of five projects that will facilitate 28 gigawatts of new power generation at the border of te MISO and South West Power Pool transmission regions, which covers the states of Iowa, Kansas, Minnesota, Missouri, North Dakota, and South Dakota. The U.S. Energy Department’s Grid Resilience and Innovation Partnerships program will cover around $464 million of the JTIQ project costs. In November, the department also announced a conditional loan guarantee of up to $4.9 billion for the 2,500-megawatt (MW) Grain Belt Express power line between Kansas and Missouri.