The California ISO has an ancillary services scarcity pricing mechanism in place that is triggered when the ISO is unable to procure the target quantity of one or more ancillary services in the integrated forward market or real-time market runs.
On Jan. 31, 2019, a regulation down scarcity occurred in the 15-minute market run in the SP26 expanded region for hour ending 22 interval 2. The procurement shortfall was 7 MW or 6.7% of the target procurement quantity.
The ISO confirmed the scarcity event during its price correction process. The published ancillary services prices correctly reflect the approved administrative set of scarcity prices.