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.
From April 17-21, 2019, ancillary service scarcities occurred in the 15-minute market run for the following regions, services and quantities:
|
Trade Date
|
Hour
Ending
|
Intervals
|
Ancillary
Service
|
Region
|
Shortfall
(MW)
|
Percentage of Requirement
|
|
Apr 17
|
14
|
3
|
Regulation Up
|
CAISO_EXP
|
4.08
|
0.9%
|
|
Apr 18
|
20
|
3
|
Non-Spin Reserve
|
CAISO_EXP
|
198.33
|
19.11%
|
|
Apr 18
|
20
|
4
|
Non-Spin Reserve
|
CAISO_EXP
|
220.02
|
21.66%
|
|
Apr 18
|
21
|
1
|
Non-Spin Reserve
|
CAISO_EXP
|
167.23
|
16.11%
|
|
Apr 18
|
21
|
2
|
Non-Spin Reserve
|
CAISO_EXP
|
31.96
|
2.72%
|
|
Apr 21
|
7
|
2
|
Regulation Up
|
SP26_EXP
|
.09
|
0.09%
|
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.
