core_eia861__yearly_reliability
Annual time series of electricity system reliability and outage impacts.
- Most-recent data:
2024
- Processing:
Data has been cleaned and organized into well-modeled tables that serve as building blocks for downstream wide tables and analyses.
- Source:
EIA Form 861 -- Annual Electric Power Industry Report (Schedules 3B and 3C)
- Primary key:
utility_id_eia, state, report_date, standard
Note: standard is included because while respondents are asked to only fill out one of parts B or C, sometimes they fill out both.
Additional Details
Contains information on non-momentary electrical interruptions. Includes the system average interruption duration index (SAIDI), system average interruption frequency index (SAIFI), and customer average interruption duration index (CAIDI) aka SAIDI/SAIFI with and without major event days and loss of service. Includes the standard (IEEE/other) and other relevant information.
SAIDI is measured in minutes, and represents the sum over the year of all customers interrupted times the number of minutes they experienced an interruption, divided by total number of customers.
SAIFI is measured in customers, and represents the sum over the year of the total number of customers that experienced an interruption, divided by the total number of customers.
The IEEE standards which can be used to calculate SAIDI and SAIFI include IEEE 1366-2003 and IEEE 1366-2012. These standards define momentary interruptions as having a duration of five minutes or less. If one of these IEEE standards is used, respondents fill out part B and are required to specify:
SAIDI major event days minus loss of supply
SAIFI major event days minus loss of supply
SAIDI and SAIFI major event days minus loss of supply excludes events where the reliability event resulted from an event on the distribution system, not from the high-voltage system. The voltage that distinguishes the distribution system from the supply system is given in highest_distribution_voltage_kv.
If a method other than these IEEE standards is used for calculating SAIDI and SAIFI indexes, respondents fill out part C and are required to specify:
whether inactive accounts are included
how they define a momentary interruption (less than 1 minute, less than or equal to 5 minutes, or other)
In this table, column standard is "ieee_standard" for respondents who have filled out part B, and "other_standard" for respondents who have filled out part C.
Columns
Average number of minutes per interruption (SAIDI/SAIFI) including major event days and excluding reliability events caused by a loss of supply.
Average number of minutes per interruption (SAIDI/SAIFI) including major event days.
Average number of minutes per interruption (SAIDI/SAIFI) excluding major event days.
Number of customers.
Entity type of principal owner.
The highest voltage that's part of the distribution system.
Whether the respondent includes inactive accounts in its definition of customers used to determine SAIDI and SAIFI.
How the respondent defines momentary service interruptions: less than 1 min, equal to or less than 5 min, or some other way.
Whether the information about customer outages is recorded automatically.
Date reported.
Cumulative duration (minutes) of interruption for the average customer during the report year including major event days and excluding reliability events caused by a loss of supply.
Cumulative duration (minutes) of interruption for the average customer during the report year including major event days.
Cumulative duration (minutes) of interruption for the average customer during the report year excluding major event days.
Average number of times a customer experienced a sustained interruption (over 5 minutes) during the report year including major event days.
Average number of times a customer experienced a sustained interruption (over 5 minutes) during the report year including major event days and excluding reliability events caused by a loss of supply.
Average number of times a customer experienced a sustained interruption (over 5 minutes) during the report year excluding major event days.
Whether the reported information comes from the short form. In the case of form EIA 861, a shorter version of the form was created in 2012 to reduce respondent burden on smaller utilities and increase our processing efficiency.
Whether the respondent calculates SAIDI/SAIFI, and major event days according to the IEEE or an Other standard.
Two letter US state abbreviation.
The EIA Utility Identification number.
The name of the utility.
Maturity of the source data published by EIA that is reflected in this record. EIA releases data incrementally over time, including monthly updates, annual year-to-date updates, provisional early releases of annual data, and final annual release data that is not expected to change further. Records sourced from multiple upstream EIA datasets may have no well defined data maturity. Records whose values have been inferred within PUDL will also have no data maturity.