Notice

02/19/2025

REQUESTED ACTION

Information only

CATEGORIES

Markets
Operations

Ancillary Services Scarcity events on 2/7-9/25

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 Feb. 7 to 9, 2025, ancillary service scarcity occurred in the 15-minute market run for the following regions, services and quantities:

Trade  

Date  

Hour Ending

Interval

Ancillary Service

Region

Shortfall (MW)

Percentage of Requirement

Feb 07

16

2

Regulation Down

NP26_EXP

2.93

0.5%

Feb 08

15

3

Regulation Down

NP26_EXP

24.35

3.95%

Feb 08

16

2, 3

Regulation Down

NP26_EXP

9.15

1.8%

Feb 09

15

2

Regulation Down

NP26_EXP

9.89

1.4%

Feb 09

15

3

Regulation Down

NP26_EXP

17.89

2.5%

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.

Contact information

Please contact Jennie Araj at 916-351-2165 or jaraj@caiso.com with any questions.

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