Static snapshot. This site serves two different things: 1,853 data centres reported by OpenStreetMap contributors nationwide, and 13 sites Helios infers from Arizona parcel records, exported on July 29, 2026. The first is a map of what has been recorded; the second is an argued hypothesis with an evidence chain. This is a point-in-time export, not a live view. See meta.json or the methodology.

Madison County

County in AL · 7 data centres recorded in OpenStreetMap

Mapped facilities
7
on the map today
Floor area
0.23
km² across 7 buildings
Share of US load
253
MW, inferred upper bound
Water
0.55
million gal/day, inferred

When these appeared on the map

observed, not surveyed
036202120212022202220232023202420242025
Data centres recorded in OpenStreetMap at the end of each month. The hatched stretch is before 2017-01, when telecom=data_center was not yet in common use — the near-zero readings there describe the tag, not the country. This is a count of what has been mapped, and OpenStreetMap carries no construction dates.
1 of these 7 facilities do not appear in the curve. The chart counts facilities whose appearance was observed in OpenStreetMap's edit history; one mapped before 2012 has no creation edit to observe. The two numbers answer different questions — how many are on the map now, and how many were watched arriving — and neither is wrong.

What the grid here looks like

reported by OSM contributors
Substations
19
69 kV and above
Bulk substations
1
230 kV and above
Highest voltage
500
kV, present in this county
Generating capacity
43
MW across 6 plants

A facility drawing hundreds of megawatts connects at bulk transmission voltage, so the second figure matters more than the first: forty 69 kV yards are not a substitute for one 500 kV substation. 4 of the plants here carry no capacity tag, so the megawatt total is a floor rather than the region's output.

Proximity is not connection. Nothing here shows that any facility has contracted power from any of these substations. That gets settled in interconnection filings Helios cannot read, and in several regions those queues now run for years. A county showing no substations may have none mapped rather than none standing.

Largest named mapped records

by mapped area
NameOperatorMapped asMapped area m²Share MWFirst mapped
Meta Huntsville Data centerMetaBuilding79,63287.32024-02-19
Meta Huntsville Data centerMetaBuilding53,73058.92024-02-19
Meta Huntsville Data centerMetaBuilding32,76235.92024-02-19
SimpleHelixnot recordedBuilding1,5251.72023-04-08
George C. Wallace Alabama Supercomputer CenterAlabama Supercomputer AuthorityBuilding1,3861.52022-11-15

“First mapped” is when OpenStreetMap recorded the facility, not when it was built — OpenStreetMap carries no construction dates. Mapped area means a building floor plate, campus boundary, or construction polygon according to the “Mapped as” column; those quantities are never added together. The megawatt column appears only for buildings and is their floor-area share of a reported national total, not a measurement.