Dive Brief:

• The California Independent System Operator's Board of Governors this week approved a rule enhancement to enable its systems to automatically model the potential loss of power plants unexpectedly going offline.
• The rule change will help improve overall market efficiency and readiness, according to CAISO. A similar rule is in place for the Western Energy Imbalance Market (EIM).
• CAISO's board also authorized extending a reliability must-run contract through 2018 for three 55 MW generating units located in the Oakland area.

Dive Insight:

CAISO's current grid models only consider potential transmission outages — but not power plants unexpectedly going offline, which the operator said means generator outages must be managed through manual intervention.

"Generators have plans in place to automatically disconnect their units or shed load to prevent system overloads in the event of an unexpected transmission line outage," CAISO explained in a recent statement. The new rule will mean that "grid operators can rely on enhanced modeling to automatically monitor potential generator issues that could result in electrical flows exceeding operating standards."

The rule must also be approved by the Federal Energy Regulatory Commission. CAISO also said that a Western Energy Imbalance Market element of the rule was approved by the EIM Governing Body about two weeks aho, and was approved on the Board's consent agenda.

The EIM allows power trading between states without the authority of a full ISO, and has helped save consumers millions of dollars while avoiding the curtailment of renewable energy.

Also at the CAISO board meeting, a reliability must-run contract was extended for three 55 MW Dynegy Oakland generating units located through 2018. CAISO said the contract is for generation capacity not picked up by a utility contract "but is required to maintain reliability, especially during heat waves, while the price is administratively set."