Wednesday, March 20, 2019

CAISO Eases Rules for Energy Storage, DERs

CAISO moved to update its rules Wednesday to make it easier for energy storage and distributed energy resources (ESDER) to participate efficiently in its markets.

The ISO’s Board of Governors adopted the ESDER Phase 3 Tariff changes at its monthly meeting in Folsom.

Among the technical updates were new bidding and real-time dispatch options for demand response resources. Stakeholders had expressed concern that many resources couldn’t respond to ISO dispatches in real time because they didn’t have enough notice.

Currently “they only have two-and-a-half minutes of notification time to respond to that dispatch,” which isn’t feasible for many, Greg Cook, CAISO’s director of market and infrastructure policy, told the board.

The new bidding options give DR resources more time to respond by letting them provide real-time market bids as an hourly block or a 15-minute dispatch resource. (See CAISO Updates ESDER Phase 3 Proposal.)

Another provision adopted Wednesday simplifies rules for aggregated DR resources.

CAISO currently requires DR resource aggregation to be contained in a single load-serving entity with a 100-kW minimum. That minimum threshold has been a problem, especially with the proliferation of community choice aggregators, Cook told the board. The new rules will remove those requirements.

CAISO adopted rules to ease the integration of distributed energy resources to California’s grid, including electric-vehicle battery storage. | U.S. Air Force/Sarah Corrice

Other changes will make it easier for behind-the-meter battery storage to absorb excess electricity and return it to the grid, and will allow for electric vehicles’ charging performance to be measured separately of their host facilities.

The changes are detailed in a memo to the board. The revisions must still be approved by FERC.

— Hudson Sangree