Having agreed on a first potential interregional project with MISO, SPP is moving the 115-kV line in South Dakota through regional review.

SPP Interregional Coordinator Adam Bell told the Seams Steering Committee on June 14 that staff is working with the Economic Studies Working Group to develop a draft scope of the project.

The working group recommends using Futures 1 and 3 from the updated 2025 models in the 2017 Integrated Transmission Planning 10-Year Assessment to calculate the project’s one-year benefit-to-cost ratio. The group is also recommending using adjusted production cost and transmission outage mitigation as metrics in computing the ratio.

The SSC and ESWG will be the primary stakeholder groups directing the regional review, Bell said. They will make a recommendation to the Markets and Operations Policy Committee, with any approval from the Board of Directors coming in October.

The RTOs’ Interregional Planning Stakeholder Advisory Committee endorsed the $5.2 million project in April, and both stakeholder groups have since given their sign-off.

The project loops a Split Rock-Lawrence 115-kV circuit into Sioux Falls to relieve congestion on the Lawrence-Sioux Falls 115-kV line, shared by the Western Area Power Administration in SPP and Xcel Energy in MISO.

The project was the only one of seven joint recommendations to survive a coordinated system study conducted by the RTOs last year. Some of the projects failed to pass muster because of a $5 million threshold for interregional projects, a metric both RTOs are open to changing. (See 1 Project Recommended for MISO-SPP Coordinated Plan.)

SPP Continuing to Study Overlapping Charges

SPP staff continues to gather data on overlapping charges along the RTO’s seam with MISO, part of a coordinated effort by the two grid operators to determine the size of the problem they’re dealing with and whether agreements between transmission owners address transmission service.

Clint Savoy, senior interregional coordinator, said the issue arose with a MISO TO’s emergency tie agreement with an SPP member. The load was reliant on SPP facilities for service.

“We’re still reliant on the transmission owners and customers to tell us when these events occur,” Savoy said. “It would save the transmission customers money, without requiring system changes.”

Savoy said feedback from members has been slow so far, but staff is following up with those who have not yet responded.

The options before SPP and MISO include:

• Revising their Tariffs and/or joint operating agreement to allow for after-the-fact reservations of transmission service for “abnormal” system conditions without unreserved-use penalties;
• Revise the Tariffs and JOA to allow for after-the-fact accounting between transmission providers for abnormal system conditions without unreserved-use penalties;
• Make no changes and still apply penalties when service is not prearranged; or
• Revise Tariffs and/or market protocols to require settlement-location registration for any potential situations, or provide for a proxy for pricing congestion and losses.

Savoy said SPP’s Regional Tariff and Market working groups will take up the discussion and draft revision requests that might be necessary.

MISO Sends $2.15M in M2M Payments to SPP

Market-to-market payments from MISO to SPP in April dropped to almost half of those in March, with SPP collecting $2.15 million for congested flowgates between the two RTOs. MISO had sent its neighbor $3.98 million in March.

SPP has now collected $21.4 million from its neighbor since the two began the M2M process in March 2015.

Temporary flowgates racked up most of the payments ($1.38 million), binding for 435 hours. Permanent flowgates, which normally account for most the payments, were binding for 347 hours.

— Tom Kleckner