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.
On July 16 and July 18, 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
|
|
July 16
|
11
|
1
|
Regulation Up
|
NP26_EXP
|
0.1
|
0.08%
|
|
July 16
|
11
|
2
|
Regulation Up
|
NP26_EXP
|
0.1
|
0.08%
|
|
July 18
|
4
|
3
|
Regulation
Down
|
SP26_EXP
|
1.16
|
1.12%
|
|
July 18
|
12
|
2
|
Regulation
Down
|
SP26_EXP
|
0.17
|
0.16%
|
|
July 18
|
13
|
3
|
Regulation
Down
|
SP26_EXP
|
0.25
|
0.24%
|
|
July 18
|
15
|
3
|
Regulation
Down
|
SP26_EXP
|
0.41
|
0.39%
|
|
July 18
|
23
|
2
|
Regulation
Down
|
SP26_EXP
|
3.29
|
3.23%
|
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. 
