EDAM Is Live: PacifiCorp And CAISO Successfully Launch New Market May 1 - 05/01/26
FOR IMMEDIATE RELEASE
PacifiCorp media hotline: 503-813-6018
CAISO contact: Jayme Ackemann 916-579-0744
EDAM is live: PacifiCorp and CAISO successfully launch new market May 1
PORTLAND, Ore. (May 1, 2026) — The California Independent System Operator (CAISO) and PacifiCorp have successfully launched EDAM, the Extended Day-Ahead Market. Through EDAM, millions of electricity consumers will benefit from coordinated day‑ahead operations across the region.
“Customers across the West are the big winners with today’s go-live, an innovative change to how we plan and deliver power across the region,” said Ryan Flynn, president of Pacific Power. “By coordinating across a broader footprint in the day-ahead, EDAM can more effectively deploy the most efficient resources, strengthening reliability, lowering costs, and enabling greater integration of diverse energy resources.”
Elliot Mainzer, President and CEO of the ISO, said, “The successful launch of EDAM marks the next chapter in the evolution of a geographically diverse and electrically connected Western electricity market.”
“We are grateful for the partnership with PacifiCorp and a broad coalition of Western energy stakeholders who helped bring EDAM to fruition. By working together, we are delivering greater reliability and affordability for energy consumers across the region, and we remain committed to continually strengthening the market to meet the challenges and opportunities facing the Western grid.”
EDAM was developed through a collaborative, transparent and highly iterative stakeholder process that engaged utilities, regulators and a broad range of energy interests across the West and builds on the success of the Western Energy Imbalance Market (WEIM). Since its 2014 launch, the real-time market has balanced electricity supply and demand every five minutes using the lowest‑cost energy across a large, interconnected footprint.
By expanding regional coordination into the day-ahead timeframe, when most electricity deliveries are planned, EDAM will leverage the West’s diverse resource mix and increasingly interconnected transmission system. Larger scale and regionally coordinated day‑ahead planning allows operators to make more optimized resource commitments and transmission usage across major supply and load centers, to better prepare the system to meet real‑time needs, improving both efficiency and reliability.
Since joining the Western Energy Imbalance Market when it was launched, PacifiCorp has generated more than $1.1 billion in benefits for its customers, according to quarterly market benefit reports.
PacifiCorp, headquartered in Portland, Oregon, owns and operates the largest privately owned transmission system in the Western U.S. The utility operates two balancing authority areas and serves 2.1 million customers through its two retail divisions: Pacific Power in California, Oregon and Washington and Rocky Mountain Power in Idaho, Utah and Wyoming. In addition to balancing electricity supply and demand for about 80% of California and part of Nevada, the ISO operates the real-time Western Energy Imbalance Market, EDAM, and RC West, which is the reliability coordinator for the bulk electric system across a large portion of the Western United States.
Continued Market Growth
The WEIM currently includes 22 participating entities across 11 states, representing about 80% of electricity demand in the West. BHE Montana and Black Hills Energy are scheduled to join shortly, bringing South Dakota into the market as the 12th participating state.
Since its launch, the WEIM has generated more than $8.6 billion in benefits for participating utilities and their customers, largely by reducing unnecessary production costs through efficient energy transfers. Those transfers have strengthened reliability by enabling regions with excess supply to assist areas facing grid stress from extreme weather, wildfires or other emergencies. The real‑time market has also supported emissions reductions by facilitating increased use of available clean energy resources.
EDAM is also positioned for steady expansion. Portland General Electric has signed an implementation agreement and is scheduled to begin participating in October.
Additional utilities have signed implementation agreements and plan to join EDAM in 2027, including the Los Angeles Department of Water and Power, the Balancing Authority of Northern California (which includes the Sacramento Municipal Utility District), the Public Service Company of New Mexico and the Turlock Irrigation District. Once these entities are participating, EDAM is expected to serve approximately 42% of electricity demand in the West, based on data from the North American Electric Reliability Corporation.
The Imperial Irrigation District has committed to join both WEIM and EDAM in 2028, and several other Western utilities are evaluating participation, including NV Energy and Idaho Power.
A Market Designed for Flexibility and Collaboration
EDAM is a voluntary market that preserves balancing authority autonomy while accommodating the West’s diverse policy and planning frameworks. Participation decisions are made independently by each entity, and CAISO will continue to fully support participation in the WEIM regardless of whether entities choose to join EDAM.
The market is built on a proven technology platform to help minimize entry costs, includes no exit fees, and uses a daily resource sufficiency evaluation that is compatible with the range of resource adequacy programs used across the West. EDAM supports efficient energy transfers across existing transmission lines and compliance with multiple state greenhouse gas regulatory programs. The EDAM design and related tariffs have been approved by the Federal Energy Regulatory Commission.
Successful implementation of a market of this scale depends on disciplined execution, performance monitoring and ongoing coordination with participants. Now that EDAM is operating, the focus will be on tracking outcomes and working collaboratively with stakeholders to make refinements as needed.
As PacifiCorp and CAISO prepared for the market’s launch, CAISO and market participants across the West embraced significant governance reforms. In July of 2025, the Western Energy Markets Governing Body assumed primary authority over market rules and gained independent filing rights at FERC.
Following passage of California Assembly Bill 825, decision-making over market rules could shift - no earlier than January 2028 – from the Governing Body to the newly established, independently governed Regional Organization for Western Energy, or ROWE. The bill allows California utilities and CAISO to participate in a market governed by an independent entity, provided specific conditions are met. The ROWE was incorporated last year to fulfill this role. Those conditions are grounded in the West-wide Governance Pathways Step 2 proposal and emphasize open, transparent, inclusive and public interest-focused governance.
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About the California ISO
250 Outcropping Way, Folsom, CA 95630 | www.caiso.com
The California Independent System Operator (ISO) is a nonprofit public-benefit corporation dedicated, in partnership with stakeholders, to the secure and reliable operation of the grid for the benefit of electricity consumers. The ISO leads comprehensive grid planning, provides open and nondiscriminatory access to a major high-voltage transmission network, and operates competitive electricity markets that promote reliability and efficiency.
About the Western Energy Markets
The Western Energy Imbalance Market (WEIM) is a real-time wholesale energy trading market that enables participants across the West to buy and sell energy when needed. Launched in 2014, WEIM has delivered over $8 billion in benefits to market participants.
Building on WEIM’s proven economic, reliability, and environmental benefits, the Extended Day-Ahead Market (EDAM), launched May 1, 2026, optimizes the use of existing transmission and resources across a broader Western footprint. This enables balancing authorities to pre-position least-cost generation to meet next-day demand and unlock significantly greater regional benefits.
About PacifiCorp
PacifiCorp is one of the lowest-cost electrical providers in the United States, serving two million customers. The company operates as Rocky Mountain Power in Idaho, Utah and Wyoming and as Pacific Power in California, Oregon and Washington. PacifiCorp provides safe and reliable service through a vast, integrated system of generation and transmission that connects communities as the largest regulated utility owner of wind power in the West. For more information, visit PacifiCorp.com.
