Puget Sound Energy said May 12 that it is joining Markets+, marking another win for SPP shortly after the Bonneville Power Administration issued its final market policy in favor of the day-ahead market. 

Washington-based and investor-owned utility PSE announced in a news release that it has signed an agreement with SPP’s Markets+, saying the day-ahead market’s governance structure was a key factor in the decision.  

The announcement comes three days after BPA issued its decision May 9 to join SPP’s Markets+ instead of CAISO’s Extended Day-Ahead Market. BPA’s decision was perhaps unsurprising given a draft policy the federal power agency issued in March that emphasized the benefits of Markets+. (See related story, BPA Chooses Markets+ over EDAM.) 

Still, BPA’s announcement in favor of Markets+ represented “a crucial development enabling PSE to fully leverage the benefits of this new market structure, given the interconnected nature of its electric transmission operations with BPA in the Pacific Northwest,” PSE stated. 

“As BPA’s largest transmission customer, this coordination can deliver substantial operational efficiencies and cost benefits for our customers,” Josh Jacobs, PSE’s vice president of clean energy strategy and planning, said in a statement. “This collaborative approach allows us to actively participate in the market’s development while preserving our ability to serve our customers’ specific needs.”    

SPP has officially set Oct. 1, 2027, as the go-live date for Markets+, its centralized, day-ahead offering in the Western Interconnection. Between now and then, much will happen, with Sept. 1, 2025, emerging as a key date. That is the deadline for balancing authorities to join in time to be a part of the market when it goes live. 

Entities like Xcel Energy subsidiary Public Service Company of Colorado, El Paso Electric and Tacoma Power already have committed to joining SPP’s day-ahead market. (See Tacoma Power to Join SPP’s Markets+, 4 Arizona Utilities Commit to Joining Markets+ and PSCo Seeks to Join SPP’s Markets+.) 

When asked if BPA’s decision could influence other entities, Carrie Simpson, SPP vice president of markets, told RTO Insider that BPA’s policy “may support the evaluation process for other entities, which could result in others moving forward with decisions on market choice.” 

PSE, which has been known to lean in favor of SPP’s market option, emphasized opportunities in Markets+ to expand renewable integration within the day-ahead market’s geographical area. 

“Additionally, the program strengthens resource adequacy through regional coordination, allowing for more efficient use of existing resources and improved reliability for customers,” PSE said in the statement. 

PSE also touted Markets+’s “member-driven governance structure,” saying it allows the utility to “appropriately” represent its customers. The governance issue has been a significant focus for potential participants weighing whether to join Markets+ or EDAM. 

BPA, like others in favor of Markets+, has often stated the SPP market’s governance structure is “superior” to that of EDAM, despite ongoing efforts by the West-Wide Governance Pathways Initiative to relax the state of California’s oversight of CAISO’s EDAM and Western Energy Imbalance Market (WEIM) by handing over governance to a proposed independent regional organization. 

“PSE supports the incremental development of greater independence for CAISO and the West. Governance was just one factor among many that PSE considered in its market decision,” Phil Haines, PSE director of energy supply and trading, told RTO Insider. 

PSE said it “looks forward to working with SPP and other regional participants through Phase 2 development and toward market implementation.”