CAISO and SPP have made “significant progress” on adapting existing tools to tackle seams between the two entities’ respective day-ahead markets, according to a CAISO representative.

As the Bonneville Power Administration prepares to join Markets+, the agency hopes to complete the initial program governance setup and define its commercial model for market participation in early 2026.

A new FERC report adds to the growing body of work showing the complexity of confronting the seams issues likely to arise between the West’s two day-ahead markets when compared with challenges at the borders between RTOs and ISOs in the Eastern U.S.

SPP stakeholders resoundingly rejected a proposed tariff change to integrate large loads, pushing back against what some say is a rushed process outside of the normal stakeholder structure.

After about 15 years, MISO appears ready to say goodbye to its stakeholder-run Seams Management Working Group.

MISO generation developers pushed back on MISO’s cost allocation of the $1.65 billion Joint Targeted Interconnection Queue, reportedly saying MISO’s late-stage alterations have eroded the value of the seams planning.

Though BPA removed any uncertainty by selecting SPP’s Markets+ over CAISO’s EDAM, the debate over whether BPA made the right choice likely will heat up as the West confronts a split into two major markets.

Bonneville's final record of decision will come as little surprise to those who’ve been following market developments in the West.