Real-time imbalance energy offset (2009)

In response to inquiries by market participants regarding the real-time imbalance energy offset (Charge Code (CC) 6477) for the month of April, the California ISO conducted a review of the first monthly invoice published under the new market model launched April 1, 2009. The ISO seeks to discuss its findings with stakeholders. The imbalance energy offset is calculated by summing the settlement dollar values for the following charge codes: real-time instructed imbalance energy (CC6470), real-time uninstructed imbalance energy (CC6475), real-time unaccounted for energy (CC6474) and the Hour-Ahead Scheduling Process (HASP) energy, congestion and loss pre-dispatch (CC6051), less real-time congestion offset (CC6774). Consistent with Section 11.5.4.2 of the ISO Tariff, allocation of CC6477 is based on measured demand in pro rata share to all scheduling coordinators including Metered Sub-System operators that are not load following and have elected gross settlement.

Outcome

Board of Governors decision: September 11, 2009
FERC Order: November 9, 2009
Implementation/Effective: October 1, 2009

The ISO requested to exempt load and exports of load following metered subsystems (MSSs) from the allocation of the real-time imbalance energy neutrality offset. If revenues are insufficient, the ISO will charge a demand, and if the revenues exceed the amount needed to pay supply, the excess will be returned to demand.