Proponents of SPP’s Markets+ argued in their last “issue alert” that the day-ahead market option provides a robust footprint with “exceptional generation and load diversity” across the region while also claiming recent warnings about its seam with CAISO’s EDAM are overblown.

Public Service Company of Colorado asked the Colorado Public Utilities Commission for permission to join SPP’s Markets+.

BPA would have to strike several types of agreements, many of which are complex and could take years to implement, to tackle seams that could arise if BPA joins a day-ahead market, agency staff said during a workshop.

MISO and SPP staff told stakeholders that they will not perform a Coordinated System Plan in 2025 but will accept transmission issues for their annual review early in the year.

MISO, PJM and SPP have failed for years to find a suitable replacement for a 20-year-old system reference they use to portion out flow rights on their system, the so-called freeze date.

SPP attempted to allay concerns about its ability to dispatch power among various Western regions during a webinar intended to illustrate its experience with seams management.

BPA’s choice of a day-ahead market will not be driven by concerns about the impact of the seams that would divide the two markets proposed for the West, an agency official made clear.