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 Oct. 20-30, 2020, ancillary service scarcity 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
|
Oct 20
|
1
|
2
|
Regulation Down
|
SP26_EXP
|
0.69
|
0.4%
|
Oct 23
|
7
|
4
|
Regulation Down
|
SP26_EXP
|
4.8
|
3%
|
Oct 24
|
4
|
2
|
Regulation Down
|
SP26_EXP
|
0.47
|
0.3%
|
Oct 24
|
6
|
1
|
Regulation Down
|
SP26_EXP
|
2.88
|
2%
|
Oct 26
|
4
|
1
|
Regulation Up
|
NP26_EXP
|
0.07
|
0.1%
|
Oct 26
|
7
|
2
|
Regulation Down
|
SP26_EXP
|
3.98
|
3%
|
Oct 27
|
6
|
4
|
Regulation Down
|
SP26_EXP
|
3.11
|
2%
|
Oct 30
|
9
|
1
|
Regulation Down
|
SP26_EXP
|
6.74
|
3%
|
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.