MISO and SPP “seams study” could boost renewables

In early March, electric grid operators Midcontinent Independent System Operator (MISO) and Southwest Power Pool (SPP) released the results of their 18-month study focused on improving reliability and resolving targeted transmission constraints along their shared boundaries or “seams.” The project, also known as the Joint Targeted Interconnection Queue (JTIQ) study, focused on developing transmission where there is congestion between the two regional transmission operator (RTO) territories to support the evolving resource mix shared by both regions. 

The process involved an “extensive stakeholder process,” said the RTOs. The result of the study is a seven-project portfolio with a planning-level estimated cost of $1.65 billion. The transmission projects would mitigate constraints, improve transfer capability between the two RTOs, and better align the MISO and SPP interconnection processes, they said. 

List of Projects Compromising the JTIQ Portfolio. Credit: MISO and SPP

In addition, economic analysis conducted by the RTOs shows customers can anticipate an Adjusted Production Cost (APC) benefit of $724 million in the MISO footprint and $247 million in the SPP region.

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The JTIQ Study portfolio allows for an increase in generator connections, according to the RTOs. A range of between 28 GW and 53 GW of improved interregional generation enablement would be available to new generator interconnection projects near the seam. Cost allocation discussions for these interregional projects are underway and projects are subject to approval from the respective boards of directors of each RTO. 

“This collaborative process provided us with the opportunity to coordinate solutions to reliability issues along the MISO-SPP seam while also looking at process improvements,” said Aubrey Johnson, executive director, systems planning and competitive transmission at MISO.

 “Both MISO and SPP have existing planning processes, and the JTIQ partnership allowed us to focus on future reliability risks based on the trends in our generation portfolios,” added Antoine Lucas, vice president, engineering at SPP. “The resulting portfolio of projects fully resolves the set of transmission constraints evaluated in the study, providing considerable reliability benefits to both RTO regions.” 

Full report is available here.