The Organization of MISO States and Organization of PJM States Inc. have dropped a second letter at MISO and PJM’s doorsteps to emphasize the need for vigorous interregional transmission planning.

This time, the regulators asked in an Oct. 24 letter that MISO and PJM’s interregional transfer capability study include more steps to ensure MISO and PJM conduct wide-ranging and transparent planning.

State regulators requested MISO and PJM as soon as possible compile a list of projects under consideration, their estimated costs and benefits and details as to why the projects are set to either advance or be abandoned.

OMS and OPSI said benefits “could include energy savings, reduced line losses, etc., as long as the benefits calculated lead to real, not hypothetical or theoretical, savings.”

The two organizations stressed that MISO and PJM should perform stakeholder outreach, firm up study deadlines, provide regular progress updates and communicate preliminary findings with stakeholders as soon as practical.

Most OMS members voted in favor of the letter at their Oct. 24 annual meeting; regulators from MISO South abstained from the vote. OMS President and Iowa Utilities Board Member Joshua Byrnes and OPSI President and D.C. Public Service Commissioner Emile Thompson signed the letter. They addressed it to MISO and PJM heads of planning Aubrey Johnson and Paul McGlynn, respectively.

The second letter arrives after some OMS members panned MISO and PJM’s original aim to study only smaller projects as too shallow to fit the constructive planning the regulators asked for. OMS and OPSI wrote their first joint letter in February to inspire MISO and PJM to do more interregional planning. (See Some MISO Regulators Signal Early Discontent with New MISO-PJM Interregional Study and Smaller Projects Expected from Maiden MISO-PJM Joint Tx Study.)

Regulators and the grid operators since have met repeatedly in private to discuss the goals of the study; MISO and PJM have pledged the study will be a multi-act affair, with the first likely producing smaller upgrades and later iterations tackling longer-term needs. The RTOs have said they likely will settle on a first round of small project contenders early next year.

OMS and OPSI’s second letter also recommended the RTOs conduct at least the second segment of the study in accordance with FERC Order 1920, which dictates that solutions be tested against 20-year planning scenarios.

“We understand that a 2032 planning horizon is likely appropriate to identify the near-term upgrades for phase one of this study. However, given that FERC Order 1920 imposes a 20-year planning horizon, a 20-year planning horizon would likewise be more appropriate for future studies beyond phase one,” regulators wrote.

OMS and OPSI added that a follow-up to the first study should take “a more expansive look at interregional planning, including more ambitious studies and process reforms.”

The regulators said they would welcome MISO and PJM working from a joint model and the two adding more interfaces between their systems.

Finally, OMS and OPSI advised MISO and PJM to determine their current interregional transfer capability to use it as a baseline in the study.

“This will help identify current system limitations, the extent transfer capacity is underutilized today and will inform future needs as the bulk electric system continues to evolve,” the regulators said.

In a statement to RTO Insider, PJM said it appreciated “the constructive tone of the correspondence” from OMS and OPSI.

“PJM will review the requests made and will plan to communicate our thoughts to both organizations in the near future,” spokesperson Dan Lockwood said.

MISO likewise said it appreciated the “ongoing collaboration from OMS and OPSI” on interregional studies and promised to share preliminary results of the first interregional transfer capability study at the Nov. 22 teleconference of MISO and PJM’s Interregional Planning Stakeholder Advisory Committee.

MISO spokesperson Mike Deising pointed to MISO’s work on its near-final, second long-range transmission plan (LRTP) as evidence that the RTO is prepared to advance infrastructure for reliability. At $21.8 billion, Deising said the second LRTP is the largest transmission expansion portfolio in the nation and will establish a 765-kV backbone in the footprint that will “facilitate power transfers from the eastern edge of our footprint to the Dakotas.” (See MISO Affirms Commitment to $21.8B Long-range Tx Plan in Final Workshops.)