How the numbers are built

Data Methodology

Definitions, transformations, confidence labels, and known limits for every major US Grid Explorer view.

Updated June 20, 2026

Three measurements that must not be confused

Nameplate capacity

The maximum rated output of generating equipment under specified conditions. Capacity does not describe how much electricity a plant actually produced.

Electricity generation

Energy produced over time, usually measured in megawatt-hours. Generation changes with dispatch, weather, fuel, maintenance, and market conditions.

Electricity demand

The rate at which customers consume electricity at a moment or during an interval. Regional demand is not the same as statewide capacity.

Confidence vocabulary

Final
Published as a finalized release by the source agency and used for aggregate state statistics.
Preliminary
An official early release that may be revised and is not used here for finalized state totals.
Reported
Published by an identified source, but fields may be incomplete, dated, or inferred.
Community-reported
Maintained by public contributors. Useful for discovery, but absence does not mean a facility does not exist.
Estimated
Derived or approximated rather than directly reported. Estimation should be explained near the value.

State profiles

State operating capacity, proposed capacity, generator counts, and fuel mix use finalized EIA-860 2024 generator data. Fuel categories combine related EIA technologies into reader-friendly groups. Totals may differ slightly because displayed values are rounded.

Largest-plant tables use EIA-860 2025 Early Release records for facility discovery. Those preliminary records are kept separate from finalized statewide aggregation.

Map layers and local reports

Power-plant markers use preliminary 2025 facility records. Transmission lines and substations are requested by the visible map extent; lower-voltage features appear as users zoom in. Visible-area counts are recalculated from point locations inside the current map bounds.

Local reports use straight-line distance from an approximate geocoded point. Nearby capacity does not establish which facilities serve a location. Transmission counts describe segments intersecting an approximate bounding area, not ownership or service territory.

Data centers use OpenStreetMap community records. Counts describe mapped locations only and must not be presented as complete market inventories.

Live grid signals

Regional demand uses EIA-930 hourly operating data. Recent values can be preliminary, delayed, missing, or revised. A timestamp describes the observation or source refresh, not a guarantee of real-time grid conditions.

Quality process

  1. Keep raw-source identity and source URLs in generated records.
  2. Validate coordinates and required fields before publishing.
  3. Separate finalized aggregation from preliminary facility discovery.
  4. Regenerate static profiles after reviewed source updates.
  5. Publish known limitations and accept documented corrections.