The Bonneville Power Administration is on target to enter the Western Energy Imbalance Market (WEIM) in early May after agency executives met Monday to make a final determination on its market readiness.

“BPA is on track to start participating in the Western EIM on May 3. Barring any unforeseen setbacks, we are a go,” agency spokesperson Doug Johnson told RTO Insider.

The federal power marketing agency was initially scheduled to begin transacting in the WEIM on March 2, along with Pacific Northwest utilities Avista and Tacoma Power, but in January it decided to delay entry by two months because of customer training and technology issues. (See BPA Postpones Western EIM Entry by 2 Months.)

During a stakeholder meeting in late March, BPA officials said the agency was on course for the May 3 entry despite remaining issues related to market technology. But they noted that they would still meet privately April 18 to make a final decision, citing the need for a smooth integration to best serve stakeholders. (See BPA ‘Full Speed Ahead’ on May EIM Entry, but Issues Remain.)

The decision came without fanfare or notice on the agency’s website. Johnson called it a “procedural, but important, step in our march to participation.”

That march began in 2018 with a long series of stakeholder meetings leading to a September 2019 signing of an EIM implementation agreement, followed by last September’s official decision to commit to joining the market. Over the course of those developments, BPA was already engaged in an exhaustive process to prepare its customer base of publicly owned utilities for the complexity of market integration.

BPA will be the most significant entrant into the WEIM since the market commenced operation in November 2014 with PacifiCorp, and its two utilities’ six-state territory, as its pioneering member.

With 15,000 miles of high-voltage transmission and 31 hydroelectric projects under its control, BPA will be the largest transmission and hydro provider in a market that now includes 16 members with territories spanning most of the Western Interconnection.

The agency controls about three-quarters of the transmission in the Northwest, making its system a vital link between the Northwest’s massive network of hydroelectric dams and WEIM areas in California and the Southwest that are becoming increasingly reliant on solar energy. The flexibility of hydro generation is particularly well suited to firming up the variable output of intermittent renewable resources.

BPA also owns more than 50% of the capacity on the California-Oregon Intertie, which links the Northwest into the CAISO system in Northern California, and — along with the Los Angeles Department of Water and Power — is half-owner of the Pacific DC Intertie, a 500-kV line that delivers energy into Southern California. LADWP began participating in the EIM last year.