In a move that some are calling a big step toward a future powered by clean energy, the MISO Board of Directors unanimously approved on July 25 the Tranche 1 Long Range Transmission Planning (LRTP) portfolio of new transmission projects.
The $10.3 billion investment includes 18 transmission projects in MISO’s Midwest Subregion. The grid operator found a benefit-to-cost ratio of at least 2.6, where benefits well exceed costs.
The portfolio of what MISO calls “least-regrets” projects will mean more than 2,000 miles of additional transmission lines will be built. The portfolio is the most complex transmission study efforts in the organization’s history, the grid operator said. Altogether, the new transmission will allow up to 53 GW of new generation capacity to connect to the transmission grid.
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The last time MISO approved projects close to this scale was 2011 and that effort took four years. The new project portfolio, which is larger in terms of cost and miles, took half that time, said MISO.
The lead photo represents the transmission lines approved and the table below offers more description.
The portfolio of what MISO least-regrets projects will mean more than 2,000 miles of additional transmission lines will be built. MISO looked at a variety of benefits when approving the transmission projects. It said the most important was system reliability but said that other factors included: congestion and fuel savings, avoided capital cost of local resources, avoided transmission investment, resource adequacy savings, avoided risk of load shedding and decarbonization.
In total the calculated benefit-to-cost ratio over a 20-year period was 2.6. A 40-year b/c was 4.0. (A figure from the executive summary is below.)
MISO studied six benefits when approving the transmission projects. MISO added that the lines approved are intended to solve specific transmission issues across its footprint:
- Line 1 (as identified in the table) addresses thermal and voltage issues for Western Minnesota and Eastern Dakotas.
- Line 3 provides a second low impedance path; unloads and relieves 115 kV and 230 kV issues; and relieves voltage stability.
- Line 6 relieves constraints in the Minneapolis/St. Paul metro area due to high renewable flow toward and past the Twin Cities load center; reinforces the outlet toward load centers in Wisconsin to relieve congestion; and eases thermal loading and transfer voltage stability.
- Line 7 provides an additional 345 kV path southwest across Iowa, linking the high renewable region in the west with the Quad Cities load center and 354kV outlets toward the rest of MISO.
- Line 9 relieves loading on transmission elements in Iowa, Missouri, and Illinois.
- Lines 16, 17, and 18 are expected to mitigate severe thermal issues in Michigan, Indiana, Illinois, Missouri and Iowa.
Three additional portfolios (tranches) are currently being studied by MISO. These would improve interconnectivity and serve to further boost reliability of the system.
“Collectively, the multiple tranches of the LRTP comprise one of the four key elements of MISO’s Reliability Imperative, which outlines a shared responsibility to evolve MISO’s planning, markets, operations, and systems in an orderly fashion that preserves system reliability in the face of rapid changes in the MISO region,” said MISO in its executive summary.
#EnergyTwitter reacted quickly to the announcement with heartfelt praise and appreciation.
Today, @MISO_energy delivered the largest transmission plan in US history. Essentially making transmission planning for clean energy more than just a white paper. Let this be an example that we can still do big things in the U.S., while addressing consumer needs & climate change
— Andy Kowalczyk (@ascottkoala) July 25, 2022“While Tranche 1 represents an important start, further work is needed to ensure reliability,” said Aubrey Johnson, MISO’s vice president of system planning in a statement. “Tranche 2 will focus on the MISO Midwest Subregion, Tranche 3 in MISO South, and Tranche 4 will address the limitations on power exchange between the MISO Midwest and South Subregions.”
This is big! @miso_energy approves the largest build-out of transmission lines in its history. Our statement about what this means for ratepayers: https://t.co/vlVAZob9Wz
— Citizens Utility Board of Michigan (@CUBofMI) July 25, 2022In June, state regulators told MISO in a letter that it was time to review market signals and reliability requirements, and to enhance collaboration between MISO, the states, and other entities responsible for resource adequacy. The letter, dated June 9, came a day before MISO released a joint report that said the region was projected to have a capacity deficit of 2.6 GW below the 2023 planning reserve margin requirement (PRMR). Similar to 2022, the capacity deficit in 2023 would be restricted to MISO North/Central, partially offset by exports from the South region.
Addressing market signal deficits, the regulators said, “Put simply, MISO must ensure it has the markets and planning processes in place that can deliver the reliability and economic efficiencies its members expect.”
In May, MISO said in a summer readiness workshop that it would likely need to import more non-firm energy and/or need additional energy resources to meet the 2022 summer peak demand. At the time, warmer-than-normal temperatures were forecasted throughout the MISO footprint.
