PNM, which serves over 550,000 customers and is the largest electric utility in New Mexico, becomes the seventh utility to sign an EDAM implementation agreement, joining PacifiCorp, Portland General Electric, and others. Participation is slated to begin in 2027.
“Participating in the Extended Day-Ahead Market is a great next step for our customers and the state of New Mexico,” said Don Tarry, CEO of PNM, in a July 2025 press release. “Coordination with other regional utilities can deliver real cost benefits to our customers.”
EDAM builds on the success of the Western Energy Imbalance Market (WEIM), a real-time trading platform that has generated nearly $7 billion in benefits since its 2014 launch. PNM alone has realized $170 million in savings since joining WEIM in 2021. Unlike the real-time market, EDAM allows utilities to coordinate energy purchases and transfers a full day in advance, improving reliability and cost efficiency across a broader footprint.
Independent analyses by CAISO and third-party evaluators have shown that EDAM will:
With Western states facing extreme weather events and rapid clean energy buildouts, the need for cross-state grid coordination has never been greater. According to the U.S. Department of Energy, the Western Interconnection is managing a sharp increase in variable renewable energy, with solar and wind expected to make up over 40% of capacity additions by 2030.
PNM’s entry into EDAM also activates a critical governance milestone for the Western Energy Markets (WEM). Under the 2024 Pathways Initiative reforms, the WEM Governing Body now holds primary authority over rules affecting both EDAM and WEIM. This shift enables more balanced, region-wide decision-making and is seen as a precursor to full independent market governance in the West.
“PNM’s commitment enables the first of the two important governance steps envisioned in the Pathways initiative,” said Elliot Mainzer, president and CEO of CAISO.
If California legislation moves forward, Step 2 of the Pathways Initiative would allow utilities and ISO to participate in EDAM under a fully independent regional market operator, aligning governance with models already in use in the Eastern U.S.
EDAM is expected to go live in 2026, with early adopters preparing now for implementation. PNM’s commitment boosts confidence in the market’s launch and underscores the value of regional integration at a time when states are under pressure to deliver both reliability and decarbonization.
CAISO and market participants are also preparing for broader reform discussions, including potential expansion of transmission planning coordination and harmonized clean energy procurement strategies.
