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Home > Market Operations > Outage Management > Curtailed / non-operational generator report glossary

Curtailed / non-operational generator report glossary

This list is posted in accordance with California Public Utilities Code Section 352.5. Section 352.5 requires the ISO to make a publicly available daily list of all power plants located in the state that are not operational due to a planned or unplanned outage. At this time the ISO does not at this time have information regarding the operational status of all plants located in the state. Accordingly, the non-operational generator report includes only the units for which the ISO has information.


This report includes all outages/curtailments that may be effective for the indicated dates. Because outages may overlap or may not all be simultaneously in effect, this report may indicate a different total outage/curtailment than a real-time report using only data from curtailments/outages in effect at that time.

Starting 10-Jul-2001, the ISO publishes a snapshot of unit availability. This snapshot reflects the status of units at that time only. The approximate publishing time for these reports is 15:15 Pacific Time.

Please be advised that system conditions are dynamic and this information is subject to change without further notice. Decisions based upon information contained in the California ISO site are the sole responsibility of the visitor.

Res ID

The ISO resource ID for this unit.

Res Name (Resource Name)

The Name of the generator unit which is being reported upon. Individual outages for each unit covering the reporting period are summarized under a single record.


P Planned Outage
U Unplanned Outage

For the Unit Status Snapshot, the full "Planned" and "Unplanned" terms are used. If multiple outages exist for this unit, these terms are stacked. 

Unit Maximum (Capacity)

The unit maximum rating in megawatts. Indicated as "Capacity" on the Unit Status Snapshot.


The unit owner. For some units, owners are reported to the ISO as "anonymous" and are not shown on this report.

Location (Zone)

The ISO is working to document the location for each unit. Until that project is completed, their general area will be noted. More specific locations will be added as they become available.

MW Curtailed (Curtailed)

This figure represents the total megawatts for all outages active any time during the day being reported on up to the total Unit Maximum for the unit. For units reporting multiple outages during the 24 hour period of the report, this number will probably reflect a higher curtailment than is actually in effect at any given time. Indicated as "Curtailed" on the Unit Status Snapshot.


The totals indicates reflect only the first outage displayed for a unit. Thus, if the first outage is "unplanned", the total for that unit will be shown in the "unplanned" totals even though there are "planned" outages reflected.

Information for other control areas

The ISO depends upon the other control areas for outage information for units in their control area. The information presented represents that forwarded to the ISO for the day this listing covers...

NOTE: The ISO does not generally receive specific enough information from other control areas to indicate whether a unit is unavailable at the time of the snapshot. Generally, the ISO receives only a set of dates when the units are/will be unavailable.