The 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 May 16-24, 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
|
|
May 16
|
13
|
1
|
Regulation Down
|
CAISO_EXP
|
0.97
|
0.12%
|
|
May 16
|
13
|
4
|
Regulation Down
|
CAISO_EXP
|
5.46
|
0.69%
|
|
May 16
|
14, 15
|
1
|
Regulation Down
|
CAISO_EXP
|
1.3
|
0.17%
|
|
May 16
|
16
|
3
|
Regulation Down
|
CAISO_EXP
|
0.14
|
0.02%
|
|
May 20
|
12
|
2
|
Regulation Up
|
NP26_EXP
|
12.77
|
13.84%
|
|
May 20
|
13
|
4
|
Regulation Up
|
NP26_EXP
|
11
|
11.7%
|
|
May 20
|
15
|
1-3
|
Regulation Up
|
NP26_EXP
|
11
|
11.7%
|
|
May 20
|
18
|
2, 3
|
Regulation Up
|
NP26_EXP
|
8.89
|
7.8%
|
|
May 21
|
16
|
2, 4
|
Regulation Up
|
NP26_EXP
|
0.87
|
10.86%
|
|
May 24
|
17
|
1
|
Regulation Up
|
NP26_EXP
|
14.5
|
16%
|
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.
