Rejecting, for now, cross-boundary construction, the Midcontinent ISO and the Southwest Power Pool have decided against a set of proposed interregional transmission projects conceived to alleviate congestion and better integrate expanding renewable generation across their footprints.
In a summary entitled "MISO-SPP Coordinated System Plan Study Report" released Dec. 21, the two regional transmission operators concluded that "[u]ltimately, because there was not unanimous support based on regional reviews, no proposed interregional projects evaluated in the interregional study were approved by the respective Board of Directors."
The study was commissioned in May 2016 to evaluate seven specific transmission needs that were identified in SPP's 2017 Integrated Transmission Planning study and in MISO's 2016 Transmission Expansion Planning process. It was designed to determine "whether interregional transmission solutions exist that are more efficient or cost effective than the regional solutions" set forth in those two analyses.
Of the various interregional solutions evaluated, only one — a 115-kV circuit from Lawrence, S.D., to Split Rock, via Sioux Falls — was recommended for consideration. While SPP's review concluded that the project would be of benefit to customers in both regions, MISO analysts concluded that other, intra-regional projects would be more cost-effective. Because the findings were not unanimous, the project was rejected.
"We're disappointed we can't find any of these types of projects" to move forward with, SPP COO Carl Monroe told trade publication RTO Insider after the Lawrence-Split Rock project was halted.
The decision not to collaborate on interregional projects comes even as regional transmission organizations across the country have pledged to work together to find transmission solutions across their boundaries, or "seams," and as rising penetration levels of renewable generation increase the need for trans-RTO transmission. The increase in wind and solar generation on their grids presents physical, economic and reliability challenges, causing MISO and SPP, geographically the largest RTOs in the country, to look to each other and other neighbors to help maintain reliability and keep their markets operating smoothly.
Speaking at the North American Energy Markets Association fall conference in New Orleans on Sept. 21, Regional Vice President for MISO South Todd Hillman said MISO along with SPP and the Electric Reliability Council of Texas "are all trying to get together. We've seen this wind explosion and we're wondering if the solar explosion might be next."
The issues are especially acute for MISO, which stretches from the northern border of Manitoba to the southern tip of Louisiana, in the Gulf of Mexico, and for SPP, which spans the central U.S. from the Texas Panhandle to Montana's Canadian border. In its most recent Transmission Expansion Plan 2017, MISO recommended a total of 354 new projects, totaling about $2.7 billion in investments. Getting interregional projects off the ground, however, has proven unexpectedly complicated. As the Coordinated System Plan report shows, getting unanimous support from RTOs, even when the transmission needs are clearly identified, is difficult.
MISO's Exploratory Transmission Study Final Report, prepared at the request of Michigan Gov. Rick Snyder and released on Dec. 15, similarly rejected expanded transmission with Canada, given the limited export capability between the regions. The study reviewed 16 possible transmission solutions and found that all are uneconomic.
"What we're trying to do is use the assets that we have already in place the most effective way that we can and build what we need in order to maintain reliability and economics," said SPP's Monroe at the Sept. 21 conference. "And then [to] optimize interdependent systems."
The grid operators, however, "are dependent on a lot of things."
In addition to interregional cooperation, SPP is also considering expanding its own footprint, particularly in the western U.S. As utilities in the Rockies and elsewhere in the West ponder shifting political, reliability and economic realities, "SPP expansion across the West appears inevitable," Caitlin Liotiris, a principal at Energy Strategies, an energy market and policy consultancy, said during the Western Power Trading Forum's meeting in Houston in November.
"We believe the benefits of membership speak for themselves and are easily observable," SPP spokesman Derek Wingfield said in an email. "To that end, we assume others in the West are watching us closely right now, and we welcome conversations with anyone interested in assessing a business decision that may include SPP."