HELIOSOpen AI Infrastructure Observatory
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.

Santa Clara County

County in CA · 75 data centres recorded in OpenStreetMap

Mapped facilities
75
on the map today
Floor area
0.47
km² across 69 buildings
Share of US load
512
MW, inferred upper bound
Water
1.11
million gal/day, inferred
1 of these 75 are not mapped as buildings, so no power figure is estimated for them. 1 is a campus boundary covering 0.01 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 represents.

When these appeared on the map

observed, not surveyed
03875201620182019202020212022202320252025
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
46
69 kV and above
Bulk substations
8
230 kV and above
Highest voltage
500
kV, present in this county
Generating capacity
1,673
MW across 27 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. 8 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
Digital Realty Silicon Valley SC1Digital RealtyBuilding27,68030.32016-12-16
MicrosoftMicrosoftBuilding15,48317.02016-12-16
Equinix SV5EquinixBuilding15,45116.92016-12-16
Digital Realty Silicon Valley SJC37Digital RealtyBuilding14,46415.82024-09-07
Silicon Valley SJC31Digital RealtyBuilding13,61914.92016-12-17
Csquare SFO2CsquareBuilding13,57314.92025-12-23
NTT Silicon Valley data center campusnot recordedCampus boundary13,308—2024-12-20
STACK SVY02Stack InfrastructureBuilding12,64313.92025-12-23
Equinix SV1EquinixBuilding12,54413.82016-12-16
Vantage Santa Clara CA2Vantage Data CentersBuilding12,26613.42024-09-07
Digital Realty Silicon Valley SJC34Digital RealtyBuilding12,00713.22016-12-17
Equinix SV4EquinixBuilding11,36812.52016-12-16
Csquare SFO2CsquareBuilding10,74811.82025-12-23
Equinix San Jose SV3EquinixBuilding10,19011.22016-12-16
Stack InfrastructureStack InfrastructureBuilding10,03311.02020-12-17
AmazonAmazon Web ServicesBuilding9,11810.02025-12-23
Csquare SFO1CsquareBuilding8,5659.42016-12-17
CoreSite SV2CoreSite Real Estate 1656 McCarthy, L.P.Building8,3569.22020-12-18
Equinix SV10EquinixBuilding8,0218.82023-11-29
Csquare SFO1CsquareBuilding7,7978.52016-12-17
Equinix Santa Clara SV2EquinixBuilding7,5358.32016-12-16
Cologix Santa Clara SV1 Data CenterCologixBuilding7,4968.22024-12-20
EdgeCore Silicon Valleynot recordedBuilding7,4748.22025-12-23
Stack InfrastructureStack InfrastructureBuilding7,2568.02020-12-17
Lumen Sunnyvale 1Lumen TechnologiesBuilding7,1667.82025-12-23
Equinix SV11EquinixBuilding7,1517.82023-11-29
Csquare SFO3CsquareBuilding6,6167.32025-12-23
OpenColonot recordedBuilding6,0826.72024-12-20
CoreSite SV6CoreSiteBuilding5,6736.22024-12-20
CoreSite SV7CoreSiteBuilding5,6666.22024-12-20
CoreSite SV9CoreSiteBuilding5,6126.22024-07-07
CoreSite SV3CoreSiteBuilding5,3715.92024-05-10
SV ColoSV ColoBuilding5,3615.92016-12-16
Digital Realty Silicon Valley SJC10Digital RealtyBuilding5,3005.82016-12-17
CoreSite SV4CoreSiteBuilding4,8245.32024-12-20
Evocative Santa Clara SJC11not recordedBuilding4,7775.22025-12-23
CoreSite SV5CoreSiteBuilding4,7255.22024-12-20
Digital Realty Silicon Valley SJC30Digital RealtyBuilding4,5094.92016-12-17
Dell 350 Holger Waynot recordedBuilding4,2074.62025-12-23
Digital Realty Silicon Valley SJC11Digital RealtyBuilding4,0904.52016-12-17

“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.