Search
March 22, 2026

CAISO/WEIM

The California Independent System Operator serves about 80% of California's electricity demand, including the service areas of the state's three investor-owned utilities. It also operates the Western Energy Imbalance Market, an interstate real-time market covering territory that accounts for 80% of the load in the Western Interconnection.
PGE Sees Transmission, Distribution Role in ‘Clean Energy Future’
PG&E's 2nd quarter profits fell sharply due to a series of one-time costs; but hopes to grow by providing transmission for clean energy resources.
EIM Report Shows Continued Growth in CAISO Exports
The western Energy Imbalance Market continued to boost demand for California’s surplus renewable generation last quarter.
Governance Plan Critics Urge Slowdown of Western RTO Development
Critics say CAISO is moving too quickly in its effort to get a plan for a Western RTO to California lawmakers before legislative session's end.
CAISO: Forecasting Challenges Drove Increased Regulation Requirements
CAISO  provided an explanation of its decision to increase regulation requirements in response to the growing variability on its system.
Revised Western RTO Governance Plan Highlights State Authority
CAISO released a revised set of principles for governing a Western RTO in a bid to convince skeptics that an expanded ISO will be amenable to the entire region.
Berkshire Contests Market-Based Sales Restriction in West
Berkshire Hathaway Energy is contesting FERC’s June decision to revoke the ability of the company’s subsidiaries to sell power at market-based rates.
Utah Bill Would Require Legislative OK for PacifiCorp RTO Membership
Utah lawmakers plan to draft a bill requiring PacifiCorp to gain legislative approval before joining an RTO based on an expanded CAISO.
Mountain West RTO Could Pose Competition for CAISO
A parallel effort to create an organized electricity market (RTO) is taking shape in the inland West even as CAISO attempts to expand.
Puget Sound Energy, Talen Agree to Close Colstrip Units
By Robert Mullin Puget Sound Energy (PSE) and Talen Energy reached an agreement with environmentalists to shut down Units 1 and 2 at the coal-fired Colstrip...
Study Touts Benefits of CAISO Expansion
A study suggests CAISO’s expansion into a multistate RTO could save Western ratepayers billions while helping meet emission-reduction goals.

Want more? Advanced Search