out_ferc1__yearly_rate_base
Annual time series of granular accounting data consisting of what utilities can typically include in their rate bases.
- Most-recent data:
2025
- Processing:
Data has been expanded into a wide/denormalized format, with IDs and codes accompanied by human-readable names and descriptions.
- Source:
FERC Form 1 -- Annual Report of Major Electric Utilities (Schedules 110, 118, 200, 204 219 and 320)
- Primary key:
This table has no primary key.
Usage Warnings
The data from these xbrl_factoid tables contains nested totals and subtotals - making aggregations difficult. We used FERC 1's reported calculations to determine the most granular, non-duplicative records. The reported calculations are not always perfect - we've corrected many of them, but errors could still exist.
FERC data is notoriously difficult to extract cleanly, and often contains free-form strings, non-labeled total rows and lack of IDs. See Notable Irregularities for details.
Additional Details
This table is derived from seven FERC Form 1 accounting tables with nested calculations. We reconciled these nested calculations and then identified the most granular data across the tables. Here are the three direct upstream inputs - the two detailed tables have several core_ferc1 inputs each:
out_ferc1__yearly_detailed_balance_sheet_assets
out_ferc1__yearly_detailed_balance_sheet_liabilities
core_ferc1__yearly_operating_expenses_sched320
We applied slight modifications to three columns (utility_type, plant_function & plant_status) as compared to the originally reported values in our core tables. The modifications were applied to either provide more specificity (i.e. we converted some total utility_type's into electric) or to condense similar categories for easier analysis (i.e. creating a hydraulic_production plant_function by combining hydraulic_production_conventional and hydraulic_production_pumped_storage). See pudl.output.ferc1.Exploder for more details. This table was made entirely with support and direction from RMI.
Columns
Four-digit year in which the data was reported.
PUDL-assigned utility ID, identifying a FERC1 utility. This is an auto-incremented ID and is not expected to be stable from year to year.
FERC-assigned respondent_id from DBF reporting years, identifying the reporting entity. Stable from year to year.
FERC-assigned entity_id from XBRL reporting years, identifying the reporting entity. Stable from year to year.
A manually assigned PUDL utility ID. May not be stable over time.
Name of the responding utility, as it is reported in FERC Form 1. For human readability only.
Listing of utility plant types.
Functional role played by utility plant (steam production, nuclear production, distribution, transmission, etc.).
Utility plant financial status (in service, future, leased, total).
The name of type of value which is a derivative of the XBRL fact name.
Account balance at end of year.
Freeform description of type of utility reported in one of the other three other utility_type sections in the core_ferc1__yearly_utility_plant_summary_sched200 table. This field is reported only in the DBF reporting years (1994-2020).
A category of asset or liability that RMI compiled to use as a shorthand for various types of utility assets. These tags were compiled manually based on the xbrl_factoid and sometimes varies based on the utility_type, plant_function or plant_status as well.
Actual FERC Account number (e.g. '359.1') if available, or a PUDL assigned ID when FERC accounts have been split or combined in reporting.
Indicates whether the value reported in the row is calculated, or uniquely reported within the table.
Identifier indicating original FERC Form 1 source record. format: {table_name}_{report_year}_{report_prd}_{respondent_id}_{spplmnt_num}_{row_number}. Unique within FERC Form 1 DB tables which are not row-mapped.
Indicates whether or not records with null or total values in the utility_type column were disaggregated. See documentation for process: pudl.output.ferc1.disaggregate_null_or_total_tag
Indicates whether or not records with null values in the in_rate_base column were disaggregated. See documentation for process: pudl.output.ferc1.disaggregate_null_or_total_tag
The name of the PUDL database table where a given record originated from.