By Robert Mullin

Arizona Public Service and Puget Sound Energy have met the milestones to participate in the CAISO-run Western Energy Imbalance Market and will begin trading in the market on Oct. 1.

“For APS and PSE, the bulk of the work is behind us,” Janet Morris, CAISO’s program management office director, told the EIM’s governing body during an Aug. 30 meeting.

The ISO last year developed a series of readiness criteria to ensure that new EIM participants are prepared to link up with the market.

Among the requirements: executing necessary agreements, establishing forecasting and balanced scheduling capabilities, producing accurate market settlements, and exchanging sufficient data to allow the ISO to monitor market performance.

The implementation process takes about 18 months and requires a new participant to integrate its network model — essentially a detailed blueprint of the balancing authority area’s operations — with that of the ISO. The process culminates in two months of market simulation, in which the participant operates in real conditions without transactions becoming financially binding. (See Arizona Public Service, Puget Sound Energy Enter EIM Testing Phase.)

Morris pointed out that the go-live date for APS and PSE will coincide with a significant update to the EIM’s market software. All participants, including existing members PacifiCorp and NV Energy, are required to “validate” the new market features. In the future, CAISO plans to schedule new member implementations for spring in order to avoid overlap with fall software releases.

“What’s one or two of the top things you learned from implementations to help others out there” planning to join the EIM? asked governing body member John Prescott.

“I think one of the first challenges in the early part of implementation is organizational change management,” Morris said, referring to the need for utility staff to adapt to the EIM’s operational practices. Those participants “need to understand how all the data fed into the market influences the market’s outcomes.”

Later in the implementation, new participants come to recognize the need for the two months of parallel testing, Morris added.

Governing body member Carl Linvill wondered if new participants have realized any “side benefits” from integrating their network models with the ISO.

“I think there’s a lot of benefits of having that visibility [into another balancing authority area] to enhance reliability,” Morris said. “That’s absolutely another benefit besides those coming out of the market.”

Morris told the governing body that Portland General Electric is on track to join the EIM in October 2017 after completing a scheduling coordinator agreement, identifying all participating resources in its area and providing a full network model ready for CAISO integration.

Idaho Power is also on schedule for an April 2018 start-up. An implementation agreement has been approved by FERC, and the utility plans to file for approval with the Idaho Public Utilities Commission by the end of summer. The company expects to export its network model to the ISO late next month.

Circling back to the upcoming APS and PSE implementation, governing body member Valerie Fong pointed out that it will be the first in which two utilities are integrated into the EIM on the same day — and at opposite ends of the Western Interconnection.

“We’re confident, but with that confidence we rely on a very robust support plan,” Morris said. “We plan for the worst and expect the best.”