Sources & licenses

The US grid map is built strictly from public-domain or open-licensed data. Each layer below names its source, the originating agency, and the license under which it is redistributed. This page satisfies the attribution clauses of every applicable license and is also linked from the in-map info control.

Power plants

U.S. Energy Information Administration — Form EIA-860 / 860M
Power plants
Operating electric generating plants ≥ 1 MW, with capacity, primary energy source, technology, and lat/lon. Authoritative roster updated monthly. We pull the FEMA-mirrored ArcGIS layer (Power_Plants_in_the_US) which republishes the same EIA dataset; the EIA bulk XLSX at eia.gov/electricity/data/eia860m/ is the upstream source.
License: U.S. Government Work — public domain (no restrictions on reuse).

Transmission & gas pipelines

Homeland Infrastructure Foundation-Level Data (HIFLD)
Transmission lines · Gas pipelines
Electric transmission lines (we pull ≥ 69 kV) and interstate natural-gas pipelines. The viewer's transmission layer has a voltage-threshold slider in the layer panel; lines below the chosen threshold are filtered out client-side. Default 138 kV gives a readable mix of trunk + sub-transmission; drag toward 69 kV to see lines connecting smaller substations, or toward 500 kV to isolate the EHV backbone. Originally a DHS-led collaboration; today the canonical national mirror is FEMA's ArcGIS organization (transmission, pipelines). For a discussion of the program see dhs.gov/gmo/hifld.
License: U.S. Government Work — public domain.

Basemap

CARTO + OpenStreetMap
Dark basemap tiles
The dark basemap is CARTO's free Dark Matter (no labels) raster tile service, which derives its geometries from OpenStreetMap contributors. CARTO redistribution is permitted under their Free Forever Attribution Required terms; OpenStreetMap is licensed under the Open Database License (ODbL) 1.0. The required notices are shown in the bottom-right corner of every map view.
License: ODbL 1.0 (OSM) · CARTO Attribution-Required basemap terms.

Frontier AI data centers

Epoch AI — Frontier Data Centers Hub
Frontier AI data centers
An independent dataset tracking large US AI training data centers (~35 sites accounting for ~15% of global H100-equivalent compute) using high-resolution satellite imagery, permits, and public documents. Source: epoch.ai/data/data-centers. Addresses are present in the CSV but lat/lon is not, so we geocode via OSM Nominatim (cached) in grid/_generator/fetch_data_centers.py. ~12 of 35 sites currently fail to geocode (very new, very rural lots not yet in OSM); the script keeps a cache so re-runs only retry the misses.
License: Creative Commons Attribution (CC BY) — free to use with attribution.

EV charging

DOE Alternative Fuels Data Center (AFDC), via NREL Developer Network
DC fast EV charging stations
Public US EV charging stations, filtered to those with at least one DC fast port (the highway-corridor backbone). The full AFDC corpus also includes ~65,000 Level-2 stations; we drop those at the bootstrap layer to keep file sizes modest. Fetcher: grid/_generator/fetch_afdc.py --dcfast-only. The endpoint is developer.nrel.gov/docs/transportation/alt-fuel-stations-v1/.
License: U.S. Government Work — public domain.

Electric substations

OpenStreetMap contributors (via Overpass API)
Substations ≥ 69 kV
Transmission and sub-transmission substations are pulled from OSM's power=substation tag, filtered to voltage ≥ 69 kV (or explicit substation=transmission) so the dataset reflects switching points rather than distribution-class transformers. The viewer applies a zoom-dependent filter: at low zooms only ≥ 138 kV stations render (avoids hairball density at national view), and zoom 6+ unlocks the full ≥ 69 kV set. We use OSM here because the canonical national HIFLD substations layer was retired in late-2022 and has not been republished in a public mirror; OSM coverage of US transmission-voltage substations is reasonably complete in 2026. The fetcher is grid/_generator/fetch_osm_substations.py.
License: Open Database License (ODbL) 1.0. Share-alike applies — any substantial extraction or derived database we publish must be released under ODbL with attribution to OpenStreetMap contributors.

Layers we'd like to add but currently can't

Water-stress overlay (WRI Aqueduct)
Not yet shipping — deferred for tile pipeline
OpenGridWorks shows WRI Aqueduct 4.0 baseline water stress as a polygon choropleth (CC BY 4.0). The dataset is the right size (~1500 watershed polygons CONUS) but as a translucent fill it's visually low-value next to the point layers. Deferred until the PMTiles pipeline is in place; then it becomes a cheap raster overlay at vector zooms.
Status: deferred until PMTiles pipeline lands.
Planned transmission projects
Not yet shipping — no usable source
OpenGridWorks pulls planned transmission from OurGridFuture; their underlying schema and licensing aren't published. HIFLD's Planned_transmission_line_ layer is empty (4 features, no metadata). FERC interconnection-queue exports are CSV-only with no project geometry. Adding this layer needs either a license arrangement with OurGridFuture or a custom geocode of FERC queue data — deferred.
Status: deferred until a redistributable source exists.

Out of scope (US-only build)

OpenGridWorks credits two layers we deliberately omit from this US-only port:

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