By Amanda Durish Cook

Just one project from MISO and SPP’s coordinated system plan study will move forward for individual votes on regional review, officials told the Interregional Planning Stakeholder Advisory Committee meeting Monday.

The project will loop one Split Rock-Lawrence 115-kV circuit into Sioux Falls to relieve congestion on the Lawrence–Sioux Falls 115-kV line in South Dakota, on the tie line shared between the Western Area Power Administration and MISO’s Xcel territory.

Final results showed costs of $5.2 million and a 4.42 benefit-cost ratio. MISO would pay 81% of the cost and SPP the remaining 19% based on benefit estimates for the first 20 years of the congestion-relieving project.

The project faces an obstacle course of approvals before construction can begin. MISO is conducting a project vote among Planning Advisory Committee voting sectors at a special meeting on April 27 for its portion of the IPSAC vote. SPP’s IPSAC vote will occur at its Seams Steering Committee teleconference on May 3. If both RTOs approve, the project moves into a SPP-MISO Joint Planning Committee vote and then into an IPSAC review conducted via email. If the project passes all review and votes, it will face an approval process before each of the RTOs’ board of directors.

The RTOs hope the approval process concludes in October, said Adam Bell, SPP’s interregional coordinator.

MISO and SPP considered seven potential interregional projects during last year’s coordinated system plan, and in earlier estimates, the South Dakota project fell just short of the $5 million interregional project threshold in the RTOs’ joint operating agreement. Earlier estimates also showed a more even cost split between the RTOs. (See MISO-SPP Coordinated Study Yields 1 Possible Project – For Now.) Bell said recently approved generator interconnect projects in MISO’s queue shifted more of the project’s cost to MISO, as the projects will benefit from congestion relief and increased transmission ratings.

Bell said project construction is complicated by the fact that the project is a tie-line, not wholly located in either footprint, and each RTO’s portion of the construction will be handled independently. MISO staff said how the RTOs ultimately decide to split construction on the small project could be used to define an improved process for projects that cover ground in both footprints going forward.

Bell also said that some interregional projects under consideration failed because of the $5 million cost threshold, which he said the RTOs are open to changing.

Another possible interregional project was revealed on April 19, but the $153.7 million candidate — the Lacygne-Blackberry 345-kV line, 345/161-kV transformer and Blackberry-Asbury 161-kV line in Kansas — graded out with a scant 1.03 benefit-cost ratio. MISO would be allocated 5% of the cost and the remaining 95% paid by SPP.

Davey Lopez, MISO adviser of planning coordination and strategy, said the project barely passed the required 1.0 benefit-cost ratio and the minimum 5% regional benefit thresholds in the joint operating agreement. “Any increase in cost would likely drop the benefit-cost ratio below 1, and SPP is investigating other, much cheaper solutions,” Lopez said at an April 19 MISO PAC meeting.

The project failed to win recommendation from either RTO during the interregional meeting.