MISO is juggling several transmission planning activities as it faces a cascade of new gigawatts in its interconnection queue, stakeholders heard during this week’s Planning Week.

The RTO announced a record number of new queue entrants in July, with customers submitting 353 applications representing about 52 GW of new generation. Solar generation, with 36 GW, accounts for the majority of the new generation proposals.

MISO said the 2020 queue entrants unseated the previous record of 47 GW, set in 2007, and the 44 GW that applied last year.

The new hopefuls bring the queue to 756 projects totaling 113 GW, 64% of which is solar. The grid operator is currently managing 13 queue cycles, with another cycle to open in 2021.

MISO was expecting about 25 GW of entrants this year, RTO adviser Joe Reddoch said during the Planning Advisory Committee’s teleconference Wednesday.

“More stringent requirements and transmission costs did not deter initial response,” he said, referring to stricter proof-of-land-use rules and higher network upgrade costs in recent years.

Reddoch said MISO’s use of the 2019 transmission planning futures — which executives admitted have become obsolete — likely contributed to the understated estimates. He said internal questions were raised as to whether the futures were too outdated and did not reflect a more aggressive renewable generation buildout.

Multiple Tx Planning Efforts Underway

MISO has several transmission planning initiatives underway against the backdrop of the daunting queue.

The RTO has opened a window for stakeholders to propose new planning studies for its 2021 Transmission Expansion Plan (MTEP 21). MISO’s new planning futures for 2021 predict anywhere from 148 to 352 GW of natural gas, solar and wind generation coming online over the next two decades.

“We are asking if you have any requests or input you would like to be considered for any additional studies for the MTEP 21 cycle,” MISO Project Manager Sandy Boegeman told stakeholders during a Planning Subcommittee (PSC) meeting. The idea submission window is open through Sept. 17.

At the same time, MISO is finalizing MTEP 20 projects it will recommend to the Board of Directors in October.

The MTEP 20 package now contains 513 new projects worth about $4 billion. Boegeman said the total costs are similar to last year’s package. However, she noted that this year’s $538 million spend on interconnection projects, or about 13% of MTEP 20’s costs, is about double that of MTEP 19’s.

MISO has also concluded that it should undertake long-range transmission planning studies separate from the annual MTEP study cycle. (See MISO Foresees Massive Shift to Renewables by 2040.)

Vice President of System Planning Jennifer Curran said MISO member plans portend a slew of new renewables and retirements of older, conventional resources. She told the PAC that now is the time for a new long-range transmission plan to keep the grid reliable and efficient as the resource portfolio shifts.

“MISO must focus now on solutions that anticipate and adapt to those rapid changes,” she said. She said that the long-term transmission studies will focus on renewable integration and transmission constraints, such as the import restrictions in Lower Michigan and the Midwest-South sub-regional limit.

The RTO’s last long-range transmission plan culminated in 2011’s Multi-Value Project (MVP) portfolio. Curran said this planning iteration won’t resemble that of a decade ago.

“I don’t think all these projects are going to come at once like the MVPs,” she said. “I think we could have multiple groups of projects approved periodically.”

Curran said the first projects would likely emerge next year in MTEP 21. She acknowledged that MISO has yet to work through a cost-allocation plan for the long-term projects, but it may be able to use existing allocation methods, such as the market efficiency project (MEP), for some of the MTEP 21 projects.

“But it’s important to focus on what the needs are first before we begin those conversations,” Curran said. “We don’t see cost allocation as a prerequisite for the work. … There are pros and cons for every cost allocation, and it’s going to be challenging.”

Xcel Energy’s Drew Siebenaler thanked MISO on behalf of the 10 Minnesota utilities that produced the CapX2050 transmission study for tackling long-term needs. (See CapX2050 Prompts MISO Focus on Midwest Tx.) Multiple state regulators also thanked the grid operator. The Organization of MISO States has been keen on a new long-term transmission plan since early 2019.

“We’re already seeing this portfolio shift, and we would argue some policies in the MISO states are going to accelerate this transformation,” Clean Grid Alliance’s Natalie McIntire said.

The grid operator is still working through a plan to coordinate its MTEP and interconnection-queue planning studies.

MISO proposed last month that generation project upgrades would need a minimum rating of 230 kV and cost at least $5 million to be eligible for evaluation as a possible MEP. (See MISO Unveils 1st Proposal to Consolidate Tx Planning.)

The RTO is debating whether it should align the interconnection queue and MTEP timelines and whether it should use more than one annual MTEP cycle to approve a transmission project solving multiple needs, provided the project is identified more than five years ahead of time.

MISO Senior Manager of Expansion Planning Edin Habibovic said it would probably be impossible for MISO to totally combine its interconnection queue studies with its economic and reliability planning studies. “But this doesn’t prevent us from looking at issues from a holistic point of view … to find a joint solution,” Habibovic told the PSC.

“The intent isn’t to merge these different planning studies into a single study,” MISO Senior Manager of Economic Planning Neil Shah agreed during the PAC teleconference. He added that the grid operator could investigate the concept of a consolidated planning process in the future.

Shah said MISO is currently focusing on fitting a “coordinated, not consolidated” approach that fits into existing Tariff processes. He said there are too many “moving parts” between economic planning and interconnection planning to completely merge them.

McIntire said it was worth considering a combination of some studies in the future.