In 2024, the Clean Energy Transition Institute (CETI) published two blogs posts covering the fundamentals of electricity markets for the Northwest and developments of two day-ahead market options: the Extended Day Ahead Market (EDAM) and Markets+. Each market’s tariff has now been approved by the Federal Energy Regulatory Commission (FERC), setting the stage for the creation of two intertwined day-ahead markets in the West.
We previously shared that the California Independent System Operator (CAISO) developed the Extended Day Ahead Market (EDAM) to build on the success of CAISO’s real-time Western Energy Imbalance Market (WEIM), a real-time market where electricity is sold close in time to when it is used. Since its launch in 2014, the WEIM has resulted in $7.82 billion in cumulative benefits to participants and their customers as of the end of the third quarter of 2025. The real-time market has also strengthened grid reliability by increasing collaboration between regional balancing authorities and making it easier to transfer energy around the market footprint where and when it is needed the most.
EDAM, which is scheduled to become operational in 2026, faced criticism that its governance structure disadvantaged non-California participants. In response, regulators from Arizona, California, New Mexico, Oregon and Washington initiated the West-Wide Governance Pathways Initiative (Pathways Initiative) in 2023 to explore the continued evolution of governance of Western energy markets and ensure that market benefits are maximized for all customers across the West. Representatives from Western states, utilities, federal agencies, independent power producers, consumer advocates, and public interest groups then formed a launch committee to develop a proposal for how this evolution of governance could occur.
In September, California lawmakers approved AB 825. The legislation is an outgrowth of the Pathways Initiative and allows for the creation of an expanded western electricity market overseen by a regional organization (RO), an independent entity with specific protections for individual state policies and the public interest. The legislation authorizes CAISO and California utilities to participate in energy markets governed by the RO. CAISO would operate the markets, but the RO’s board would have sole authority over the rules of the market, thereby mitigating previous concerns. CAISO would maintain its responsibilities as a balancing authority in California. It would also retain the authority, comparable to what exists for other balancing authorities in the West, to voluntarily withdraw from the regional markets if it chose to do so.
The Pathways Initiative recently moved to incorporate the new RO—named the “Regional Organization for Western Energy”—and proposed the organization’s scope and function, formation, governance, public interest protections, stakeholder engagement process, and bylaws. Next steps include establishing a representative nominating committee that will select the RO’s initial board of directors, who are expected to be seated in 2026.
PacifiCorp and Portland General Electric plan to enter EDAM when it launches in 2026. The Public Service Company of New Mexico, the Balancing Authority of Northern California, the Los Angeles Department of Water and Power, and the Turlock Irrigation District will join in 2027, and the Imperial Irrigation District will enter in 2028. Entities leaning towards EDAM include NV Energy, Idaho Power, and Power Watch (formerly BHE Montana).
As we wrote in 2024, Markets+ is a day-ahead market offering by the Southwest Power Pool (SPP), which is a regional transmission organization (RTO) based in Arkansas and operating largely in the central United States. SPP also runs a real-time market in the Mountain West and is expanding its RTO services as well.
SPP Markets+ is governed through an independent stakeholder-driven structure, so it does not have EDAM’s governance issue. However, proponents of a unified, west-wide market have concerns that a market that does not include California would reduce the overall benefits.
FERC approved the Markets+ tariff in April 2025. FERC also approved SPP’s Phase Two Funding Agreement, which outlines participants’ funding obligations towards market development. These approvals, along with commitments from market participants, cleared the path to build out Markets+.
Markets+ is expected to launch in 2027 with participation from Arizona Public Service, Salt River Project, and British Columbia’s Powerex. Utilities from the Northwest have committed to join the market in 2028 and beyond, including Bonneville Power Administration, Puget Sound Energy, Chelan County PUD, Grant County PUD, and Tacoma Power.
Ongoing preparations until the market launch include market modeling, developing and finalizing protocols for issues such as greenhouse gas allocation, and onboarding participants.
The value of a market depends on many factors including the geographic area and resources that each participant contributes. Each entity’s decision to participate in one market or another can impact the outcomes for all other entities.
This dynamic makes Bonneville Power Administration (BPA)’s decision to join Markets+ particularly significant because of its outsized share of electricity-generating resources and control of the region’s transmission system. BPA owns and operates over 15,000 miles of high-voltage transmission lines, which represents three-quarters of the high-voltage electrical transmission system in the Northwest.
In March 2025, BPA issued its day-ahead market draft policy concluding that BPA should pursue participation in SPP’s Markets+. BPA cited the Markets+ independent governance model, uniform resource adequacy requirements, greenhouse gas accounting method, and congestion revenue design as key elements that drove its decision and that would provide value to BPA customers.
The Public Power Council, which represents consumer-owned electric utilities in the Northwest that buy power from BPA, said BPA’s selection of Markets+ “aligns with key public power priorities including robust governance that provides meaningful influence for utilities, a market design that enhances regional reliability and efficiency, and a structure that supports the unique hydropower resources of the Northwest.”
Not everyone in the region agrees that BPA’s decision to join Markets+ will best serve the Northwest. Five energy and environment advocacy groups (Northwest Energy Coalition, the Idaho Conservation League, the Montana Environmental Information Center, the Oregon Citizens’ Utility Board, and the Sierra Club) filed a lawsuit in July 2025 following BPA’s announcement that it would join Markets+, arguing that BPA failed to show that Markets+participation would enable it to meet its duty to promote an adequate, efficient, economical, and reliable power supply.
In parallel with the development of a day-ahead market, the region continues to advance the Western Resource Adequacy Program (WRAP). WRAP is not a market, but a strategy for resource adequacy through a formalized, binding reliability program. Participating utilities would show an ability to meet their electricity needs and be eligible to provide or request resources during high demand times.
Six participants withdrew from the WRAP (PacifiCorp, Calpine, Eugene Water and Electric Board, NV Energy, Portland General Electric, and Public Service Company of New Mexico) shortly before the October 31, 2025 deadline to participate in the first binding season of the program, which is scheduled for winter 2027/2028. Sixteen participants remain committed to the first binding season, representing 58 GW of peak load.
There is no requirement for WRAP participants to join in either day-ahead market. However, SPP operates WRAP and the utilities that withdrew mostly plan to participate in EDAM, while utilities that remain committed are largely planning to participate in Markets+. CAISO does not currently offer a resource adequacy program that would be its own version of WRAP.
For a deeper dive into the day-ahead markets, each operator offers free online resources. For EDAM, visit the CAISO Stakeholder Center. For Markets+, visit the SPP Learning Center. Additional resources include a recent report from Grid Strategies and Western Resource Advocates entitled Managing Seams: Market Coordination in Western Wholesale Energy Markets, as well as an overview from GridStatus on EDAM and Markets+.
CETI will continue to track market development and utility commitment updates in the Northwest. In this fast-moving space, the bottom line has not changed: day-ahead markets are a key tool as Northwest utilities endeavor to maintain low-cost, reliable, clean power.
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