PacifiCorp said April 26 that it will sign an implementation agreement to join CAISO’s Extended Day-Ahead Market (EDAM), making it the first entity to formally commit to either of the two day-ahead markets being offered in the West. 

The Portland, Ore.-based company, whose sprawling territory includes portions of six states, was the first utility to join the ISO’s Western Energy Imbalance Market in 2014 and the first to publicly announce its intent to join EDAM in December 2022.  

EDAM is currently in a stiff competition for participants with SPP’s Markets+.  

“We are excited to formalize our agreement to become a participant in the EDAM,” PacifiCorp CEO Cindy Crane said in a joint announcement with the ISO. “A modern, coordinated day-ahead market in the West is vital to optimizing the region’s energy resources so we can continue to provide reliable and affordable power to our 2 million electricity customers across six states.” 

PacifiCorp serves electricity customers in California, Idaho, Oregon, Utah, Washington and Wyoming, owns 10,833 MW of generating capacity, and operates approximately 17,100 miles of transmission. The entity was the first to join CAISO’s Western Energy Imbalance Market in 2014. 

Anticipation continues to build in the West over which day-ahead market various entities will join. While PacifiCorp’s announcement marks a major achievement for EDAM, the decision won’t surprise participants in regional market discussions. 

Four other entities have indicated interest in joining EDAM. In March, Portland General Electric and Idaho Power signaled their intent to join (See CAISO’s EDAM Scores Key Wins in Contested Northwest.) The Balancing Authority of Northern California and Los Angeles Department of Water and Power have also informed the ISO of their interest in joining.  

“The momentum we are seeing for participation in the EDAM is very gratifying, and PacifiCorp’s formal commitment brings better definition to the vision of a regional day-ahead electricity market,” CAISO CEO Elliot Mainzer said in the announcement. “This is a major piece of a truly collaborative effort to support reliability and affordability for electricity customers by leveraging resource diversity and transmission connectivity across the footprint of the Western grid. We now look forward to continuing working with additional valued partners in the West to take the next steps in a fully integrated regional market.” 

Markets+ notched a potentially big win this month after Bonneville Power Administration staff recommended the federal power agency choose Markets+ over EDAM, though BPA won’t issue a draft decision until this summer. (See BPA Staff Recommends Markets+ over EDAM.)