Pacific Northwest members reaped an unusually large chunk of the Western EIM's benefits in the first quarter, leaning on it to keep up with demand.

CAISO said Monday its Western Energy Imbalance Market has produced more than a half-billion dollars in benefits for participants since its founding five years ago, including more than $100 million in benefits in the third quarter of 2018.

The Western Energy Imbalance Market saw financial benefits soar to a record $71.2 million in the second quarter, according to a CAISO report.

Powerex is navigating a turbulent relationship with EIM rules the company says undercut the value of its hydro power resources.

Idaho Power and Powerex began transacting in the EIM, bringing to eight the number of members participating in CAISO’s regional real-time market.

Operators of traditional resources say the Vision 2030 paper drifts outside CAISO’s purpose of assuring reliability and managing markets.

FERC approved CAISO’s agreement for integrating Canadian power marketer Powerex into the EIM.

The CAISO proposal to provide transmission revenue to balancing authority areas that wheel power received a wary response from EIM stakeholders.

FERC staff have accepted CAISO’s implementation agreement for Powerex to join the EIM but cautioned that the arrangement could be subject to further scrutiny.

Powerex has signed an agreement with CAISO to become the first non-U.S. participant in the Western Energy Imbalance Market (EIM).