IPWG: MISO-SPP Interim Study Improvement and Proposed BPM-015 Redlines (PAC-2022-4) (20221114)

National Grid Renewables (NG Renewables) appreciates MISO and SPP for their attention to stakeholder feedback and understanding the importance of identifying and fixing the issues related to limited injection on the seams. Interconnecting projects dependent upon pending upgrades can still inject power on the transmission system pending the building of the required upgrades.  However, in order to enable the projects’ injection, both ISOs need to engage in a regular and realistic assessments of the limits placed on the interconnecting generator.

Extending the use of the MISO Quarterly Operating Limits (QOL) studies to include both MISO generators and SPP generators is an excellent step to providing certainty and reliability for generators with conditional/provisional GIAs.

The MISO QOL process provides certainty through its regular (quarterly) study schedule. The MISO QOL methodology of utilizing operating models ensures that the most up to date, realistic dispatch and assessment of grid conditions is utilized to ensure reliability and enable maximum injection from the affected generators until the pending facilities are in-service. Utilizing the QOL methodology is considered a more accurate process compared to the previously utilized LOIS process.

NG Renewables supports the proposal for SPP to communicate thermal constraints to MISO for use in the QOL study. However, in order to maintain consistency and ensure the QOL study inputs are comparable, the constraints SPP identifies and communicates should be based on SPP’s operating models, rather than interconnection models. This would make the SPP inputs comparable with the MISO inputs and methodology and ensure that QOL analyses are assessing both systems on an “apples to apples” basis.

NG Renewables proposes the following adjustment to the BPM redlines.

• “6.4.3.2 Limitations on MISO Generators with Impacts on the SPP System. MISO Generation Interconnection projects that come into service prior to completion of required Network Upgrades on the SPP transmission system will be subject to the MISO Annual ERIS and Quarterly Operating Limit processes, with input from SPP’s Affected System study process.  SPP will coordinate thermal constraints and associated limits as identified in SPP’s operating models with MISO on a quarterly basis or more often as events occur, and SPP will provide MISO the list of conditions that will be added to MISO Generator Interconnection Agreement.”

This consolidation is a significant improvement on current practice, and NG Renewables appreciates the continued efforts from both MISO and SPP to ensure consistency and certainty for interconnecting generators.