out_ferc1__yearly_purchased_power_and_exchanges_sched326

package: pudl

Annual time series of purchased power (Account 555) including power exchanges (transactions involving a balancing of debits and credits for energy, capacity, etc.) and any settlements for imbalanced exchanges.

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 (Schedule 326)

Primary key:

This table has no primary key. The primary key for this table would be record_id, however a small number of these values are duplicated in 2021, 2022, and 2024.

Usage Warnings

  • Contains columns which may appear categorical, but are actually free text.

  • 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 has data about inter-utility power purchases. This includes how much electricity was purchased, how much it cost, and who it was purchased from. Unfortunately the field describing which other utility the power was being bought from (seller_name) is poorly standardized, making it difficult to correlate with other data.

Purchased Power is considered FERC Account 555 according to FERC's Uniform System of Accounts. Reported on pages 326-327 of FERC Form 1.

Columns
report_year

Four-digit year in which the data was reported.

utility_id_ferc1

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.

utility_id_ferc1_dbf

FERC-assigned respondent_id from DBF reporting years, identifying the reporting entity. Stable from year to year.

utility_id_ferc1_xbrl

FERC-assigned entity_id from XBRL reporting years, identifying the reporting entity. Stable from year to year.

utility_id_pudl

A manually assigned PUDL utility ID. May not be stable over time.

utility_name_ferc1

Name of the responding utility, as it is reported in FERC Form 1. For human readability only.

seller_name

Name of the seller, or the other party in an exchange transaction.

record_id

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.

billing_demand_mw

Monthly average billing demand (for requirements purchases, and any transactions involving demand charges). In megawatts.

coincident_peak_demand_mw

Average monthly coincident peak (CP) demand (for requirements purchases, and any transactions involving demand charges). Monthly CP demand is the metered demand during the hour (60-minute integration) in which the supplier's system reaches its monthly peak. In megawatts.

delivered_mwh

Gross megawatt-hours delivered in power exchanges and used as the basis for settlement.

demand_charges

Demand charges (USD).

energy_charges

Energy charges (USD).

non_coincident_peak_demand_mw

Average monthly non-coincident peak (NCP) demand (for requirements purhcases, and any transactions involving demand charges). Monthly NCP demand is the maximum metered hourly (60-minute integration) demand in a month. In megawatts.

other_charges

Other charges, including out-of-period adjustments (USD).

purchase_type_code

Categorization based on the original contractual terms and conditions of the service. Must be one of 'requirements', 'long_firm', 'intermediate_firm', 'short_firm', 'long_unit', 'intermediate_unit', 'electricity_exchange', 'other_service', or 'adjustment'. Requirements service is ongoing high reliability service, with load integrated into system resource planning. 'Long term' means 5+ years. 'Intermediate term' is 1-5 years. 'Short term' is less than 1 year. 'Firm' means not interruptible for economic reasons. 'unit' indicates service from a particular designated generating unit. 'exchange' is an in-kind transaction.

purchased_mwh

Megawatt-hours shown on bills rendered to the respondent. Includes both electricity purchased for storage and non-storage purposes, which were lumped together prior to 2021.

purchased_storage_mwh

Number of megawatt hours purchased during the period for energy storage.

purchased_other_than_storage_mwh

Number of megawatt hours purchased during the period for other than energy storage.

received_mwh

Gross megawatt-hours received in power exchanges and used as the basis for settlement.

tariff

FERC Rate Schedule Number or Tariff. (Note: may be incomplete if originally reported on multiple lines.)

total_settlement

Sum of demand, energy, and other charges (USD). For power exchanges, the settlement amount for the net receipt of energy. If more energy was delivered than received, this amount is negative.