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.

IL

State · 54 data centres recorded in OpenStreetMap

Mapped facilities
54
on the map today
Floor area
0.72
km² across 45 buildings
Share of US load
790
MW, inferred upper bound
Water
1.72
million gal/day, inferred
3 of these 54 are not mapped as buildings, so no power figure is estimated for them. 3 are campus boundaries covering 4.61 km² of land. The megawatt figure above divides a national total by building floor area, and the area of a land parcel is not floor area. A site still being built consumed none of the electricity that total measures. Both are counted here and left out of the estimate rather than folded into it, so this region's load is understated by however much those represent.

When these appeared on the map

observed, not surveyed
02754201720182020202120222023202420252026
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.

What the grid here looks like

reported by OSM contributors
Substations
1,039
69 kV and above
Bulk substations
171
230 kV and above
Highest voltage
765
kV, present in this state
Generating capacity
49,976
MW across 505 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. 195 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
Joliet Technology Centernot recordedCampus boundary3,225,9502026-06-11
DeKalb Meta Data CenterMeta PlatformsCampus boundary1,188,5322025-12-10
Microsoft Data Center - Hoffman Estatesnot recordedCampus boundary195,5862025-03-19
CyrusOne Chicago Aurora CMECyrusOneBuilding44,88249.22024-12-22
Digital Realty CH1Digital RealtyBuilding43,64247.82023-05-19
Centersquare Lisle ORD4 Data CenterCentersquareBuilding33,55736.82024-10-22
Digital Realty CH3Digital RealtyBuilding32,35135.52023-05-19
Microsoft - Azure DatacenterMicrosoftBuilding28,50031.22018-04-10
Digital Realty CH2Digital RealtyBuilding28,14730.92023-11-29
STACK Chicago CHI01Stack InfrastructureBuilding27,72930.42023-05-19
QTS ChicagoQuality Technology ServicesBuilding24,81627.22017-10-16
Stream Chicago IIStreamBuilding20,06022.02023-11-29
CyrusOne CHI3CyrusOneBuilding19,77621.72026-02-21
Centersquare Elk Grove Village Data Center Campus ORD2CentersquareBuilding18,42520.22023-05-19
Aligned Data Center - Chicago ORD-01AlignedBuilding18,07419.82025-06-18
Skybox Chicago ISkyboxBuilding16,21917.82023-11-29
T5 Chicago IIT5 Data CentersBuilding15,16516.62023-11-29
Equinix Chicago CH3EquinixBuilding12,61613.82023-11-29
Lakeside Technology Centernot recordedBuilding11,99913.22022-02-14
Stream Chicago IStreamBuilding11,20612.32023-11-29
EdgeConneX CHI01EdgeConneXBuilding11,16612.22023-05-19
Edged Chicago ORD01EdgedBuilding10,79511.82026-02-21
NTT Chicago CH2NTTBuilding10,73611.82025-10-30
NTT Chicago CH1NTTBuilding10,54811.62023-06-12
Aligned Data Center - Chicago ORD-02AlignedBuilding10,35211.32025-06-18
Iron Mountain Data & Record StorageIron MountainBuilding9,85110.82021-01-21
NTT Chicago CH4NTTBuilding9,41510.32025-10-30
Element Critical CH1Element CriticalBuilding8,5549.42023-11-29
Digital Realty Chicago ORD12Digital RealtyBuilding8,3779.22023-05-19
NTT Chicago CH3NTTBuilding7,7948.52025-10-30
Lincoln Rackhousenot recordedBuilding6,5157.12024-12-22
EdgeConneX CHI02EdgeConneXBuilding5,9796.52023-11-29
CoreSite Chicago Data Center (CH2)CoreSiteBuilding5,7396.32020-09-15
Serverfarm CH1ServerfarmBuilding5,2425.72023-02-07
VISAVISABuilding5,1105.62019-06-03
Equinix Chicago Data CH7EquinixBuilding4,3984.82025-03-24
NCSA Petascale Computing Facilitynot recordedBuilding4,2384.72024-05-08
Element Critical CH2Element CriticalBuilding4,1214.52023-11-29
Datacenter (386)UChicago Argonne LLCBuilding1,1531.32025-06-19
Digital Realty ORD11Digital RealtyBuilding8450.92024-10-30

“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.