The monthly survey Form EIA-860M, ‘Monthly Update to Annual Electric Generator Report’ supplements the annual survey formEIA-860 datawith monthly information that monitors the current status of existing and proposed generating units at electric power plants with 1 megawatt or greater of combined nameplate capacity. EIA estimates the current and near-term unit inventory of electric power generating capacity by integrating the information on these surveys along with ongoing EIA research of new units. However, creating this monthly estimate sometimes requires the use of data submitted on the annual EIA-860 before it has been fully verified by EIA. For this reason, reported capacities are EIA’s preliminary estimates of capacity for that month. Estimates will be corrected without specific acknowledgement or explanation in subsequent month’s inventory.
Starting with March 2017 data, Preliminary Monthly Electric Generator Inventory includes a comprehensive list of generators which retired since 2002. The list can be found on the ‘Retired’ tab of the datafile.
Capacities reported in this preliminary inventory are best estimates of current generating capacity, but are not meant to be capacity commitments by the associated facilities.