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 23-30, 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 23
|
20
|
3
|
Non-spin reserve
|
CAISO_EXP
|
45.71
|
3.41%
|
|
Apr 24
|
20
|
3
|
Spinning reserve
|
CAISO_EXP
|
32.21
|
2.62%
|
|
Apr 24
|
20
|
4
|
Spinning reserve
|
CAISO_EXP
|
32.79
|
2.67%
|
|
Apr 24
|
21
|
1
|
Spinning reserve
|
CAISO_EXP
|
84.77
|
7.06%
|
|
Apr 24
|
20
|
3
|
Non-spin reserve
|
CAISO_EXP
|
163.76
|
14.92%
|
|
Apr 24
|
20
|
4
|
Non-spin reserve
|
CAISO_EXP
|
163.76
|
14.92%
|
|
Apr 24
|
21
|
1
|
Non-spin reserve
|
CAISO_EXP
|
209.46
|
19.47%
|
|
Apr 24
|
21
|
2
|
Non-spin reserve
|
CAISO_EXP
|
176.56
|
15.93%
|
|
Apr 25
|
13
|
2
|
Regulation Up
|
CAISO_EXP
|
2.17
|
0.73%
|
|
Apr 27
|
6
|
1
|
Regulation Down
|
CAISO_EXP
|
1
|
0.25%
|
|
Apr 27
|
7
|
2
|
Regulation Down
|
CAISO_EXP
|
0.39
|
0.07%
|
|
Apr 27
|
7
|
3
|
Regulation Down
|
CAISO_EXP
|
1.4
|
0.26%
|
|
Apr 27
|
7
|
4
|
Regulation Down
|
CAISO_EXP
|
1.81
|
0.33%
|
|
Apr 27
|
8
|
3
|
Regulation Down
|
CAISO_EXP
|
1.4
|
0.20%
|
|
Apr 27
|
8
|
4
|
Regulation Down
|
CAISO_EXP
|
2.28
|
0.33%
|
|
Apr 27
|
13
|
1
|
Regulation Down
|
CAISO_EXP
|
1
|
0.22%
|
|
Apr 27
|
13
|
2
|
Regulation Down
|
CAISO_EXP
|
1.01
|
0.22%
|
|
Apr 27
|
13
|
3
|
Regulation Down
|
CAISO_EXP
|
1.02
|
0.23%
|
|
Apr 27
|
13
|
4
|
Regulation Down
|
CAISO_EXP
|
1.01
|
0.22%
|
|
Apr 28
|
2
|
4
|
Regulation Down
|
CAISO_EXP
|
2.97
|
0.86%
|
|
Apr 30
|
16
|
4
|
Regulation Down
|
CAISO_EXP
|
2.82
|
0.52%
|
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.
