By Amanda Durish Cook
MISO will ask FERC to end a system support resource agreement in Michigan’s Upper Peninsula, saying its reliability concerns will be addressed by American Transmission Co.’s transmission reconfiguration until an upgrade expected in service by the end of 2020.
MISO said ATC’s proposal to open transmission circuits and split the western UP load pocket into two radially-fed areas “avoids [the] risk of cascading loss of load during prior outages,” allowing the termination of White Pine Unit 1’s System Support Resource (SSR) agreement.
MISO plans to file to terminate the SSR agreement following a 90-day notice, Joe Reddoch of MISO’s System Support Resource Planning Group said during a meeting of the West Technical Study Task Force Aug. 8.
Reddoch said that the two-radial configuration would be used only during planned outages or when one of the area’s two 138kV lines is unexpectedly out of service. The load pocket would be served by the remaining 138-kV line and the Conover 69-kV line.
ATC submitted the proposal to MISO in late July. (See ATC Plan Could Eliminate White Pine SSR; Refunds Coming on Presque Isle?)
“Some of these are day-long outages. I think the longest one we looked at is somewhere in the order of a week,” Reddoch said.
MISO concluded the two-radial configuration would result in only a small increase in the risk of loss of load.
The load pocket in the western Upper Peninsula around White Pine — about 68 MW during shoulder periods and 80 MW in the summer — is supported by two 138-kV circuits and one 69-kV line. An outage of one 138-kV line followed by the loss of the second line “results in severe overloads and voltage collapse in the local load pocket,” MISO said.
The RTO said ATC’s plan would result in a “limited” increase in the risk of a consequential load shed, which could be managed within the RTO’s planning and operating criteria, which allows mitigation through reconfiguration.
“From our perspective, this is an acceptable alternative,” Reddoch said. “The radial reconfiguration isn’t unheard of in the system. It may not be ideal, but it’s certainly acceptable.”
Richard Bonnifield, an attorney for White Pine Electric Power, said stakeholders were being “blindsided” by the introduction and acceptance of ATC’s plan in the same stakeholder meeting and asked for a reliability impact analysis on the removal of White Pine. Reddoch said a reliability analysis would not provide any additional information and would serve only to “unnecessarily” delay implementing the solution.
Bonnifield fired back that the stakeholder process regarding the SSR removal was “unstructured.” Other stakeholders asked for more time to assess the alternative.
“Our assessment does not require any extensive analysis. This reconfiguration is already in place for unplanned outages. This has already been an accepted process for unplanned conditions. I don’t think we can conclude that it’s not acceptable,” Reddoch said. Ken Copp, a strategic technical advisor with ATC, confirmed that ATC’s system in the western Upper Peninsula would return to a configuration prior to the 1990s when Wisconsin Electric Power Co. and ATC tied their lines together.
Some stakeholders asked Copp why the lines were tied together in the first place.
“Back in that day, contract paths were a big deal, especially for wholesale customers. It achieved some contract path goals, but we have to label that as anecdotal, not something that’s documented,” Copp said.
Some stakeholders said the transmission reconfiguration would not be as reliable as keeping the SSR in place.
Reddoch responded that the plan isn’t in violation of planning criteria and presents a no-cost alternative for ratepayers. “It might not be ideal, but even an SSR isn’t ideal,” he said.
White Pine Electric Power requested retirement of White Pine Unit 1 in April 2014. The current SSR agreement was expected to last until 2017.
The long-term solution for the reliability concerns that gave rise to the SSR is a $100 million plan to convert the 75-mile, 69-kV transmission path from Lakota Road to Mass to Winona to 138 kV. The project, included in MISO’s 2015 Transmission Expansion Plan, is slated to be finished in December 2020.
Angela Castle of the Michigan Agency for Energy said ATC’s solution would be “much less onerous” on ratepayers.
Steve Leovy, a transmission engineer at WPPI Energy, told stakeholders that ATC presented the alternative solution despite not being directly affected by SSR costs.
“ATC isn’t in this; they don’t have to pay the SSR costs. Our ratepayers have to pay the SSR costs. We are supportive of this … and we don’t take the increased risk of load loss lightly,” Leovy said.
Reddoch said MISO will work with ATC in the coming weeks to revise the company’s operating guide to remove White Pine availability and introduce the reconfiguration plan. Details of the revised operating guide will be kept confidential per MISO procedure.
