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.

AZ-TEMPE-001

Tempe, Maricopa County, Arizona · enterprise data center Reported

Download evidence & provenance
0 No known developmentStage 7: Operational8 Expansion
Confidence (Id. / Stage)
34% / 28%
low
Site area
4.2
acres across 1 parcel
Evidence records
3
first signal 2021-08-02
Estimated load
5–20 MW
inferred from acreage — see the estimates panel
Summary. 1 parcel(s) totalling 4.2 acres near 2601 W BROADWAY RD, Tempe. Title of record is held by TIERRA DC ASSETS LLC. Helios has not established which organization, if any, operates or will operate a facility here.

Evidence timeline

4 chronological entries
  1. 2 Aug 2021
    Shell entity ownershipInferred

    Title is held by TIERRA DC ASSETS LLC, whose name shows single-purpose-entity characteristics (pass-through legal form (LLC)). This is a weak signal only: project-specific entities are routine in ordinary commercial real estate and imply no particular parent.

    OwnerName = TIERRA DC ASSETS LLC
    Source: Maricopa County Assessor Parcel LayerView original evidenceRetrieved 2026-07-25sha256:77af6d6d43fe$.features[0].attributes.OwnerNameExtraction confidence 45%
  2. 2 Aug 2021
    Stage advanced to Operational

    Stage advanced from 0 (No known development) to 7 (Operational) at 28% confidence. Principal evidence: Assessor classifies property use as data centre; Single-purpose entity holds title.

    Unclassified → OperationalDetected 1821 days after the factConfidence at transition 28%
  3. 25 Jul 2026
    Dedicated substation proximityCalculatedStanding condition

    Binary Substation tagged 69 kV lies 828 m from the site boundary, close enough for a dedicated connection to be practical. Proximity is a locational precondition, not evidence that this substation serves the site.

    name = Binary Substation; operator = Salt River Project; max_voltage_kv = 69.0
    Source: OpenStreetMap Power Infrastructure (Overpass API)View original evidenceRetrieved 2026-07-25sha256:b780b9bfc5c6OSM elementExtraction confidence 70%
  4. 28 Jul 2026
    Assessor data center classificationReportedStanding condition

    Maricopa County Assessor currently classifies this parcel's property use as DATA CENTERS (use code 1507).

    PropertyUseDescription = DATA CENTERS
    Source: Maricopa County Assessor Parcel LayerView original evidenceRetrieved 2026-07-25sha256:77af6d6d43fe$.features[0].attributes.PropertyUseDescriptionExtraction confidence 95%

Why Helios believes this

34% Low
Confidence
28%
low
Supporting weight
+19.7
2 contributions
Countervailing weight
0.0
0 contributions
Evidence diversity
2
distinct kinds across 3 records
+19.00
Assessor classifies property use as data centre
Maricopa County Assessor currently classifies this parcel's property use as DATA CENTERS (use code 1507).
base 20 × extraction confidence 0.95 × recency 1.00
+0.68
Single-purpose entity holds title
Title is held by TIERRA DC ASSETS LLC, whose name shows single-purpose-entity characteristics (pass-through legal form (LLC)). This is a weak signal only: project-specific entities are routine in ordinary commercial real estate and imply no particular parent.
base 6 × extraction confidence 0.45 × recency 0.25
+0.00
High-voltage substation in close proximity
Binary Substation tagged 69 kV lies 828 m from the site boundary, close enough for a dedicated connection to be practical. Proximity is a locational precondition, not evidence that this substation serves the site.
base 0 × extraction confidence 0.70 × recency 1.00

Scored by helios-rule-based version 0.1.0 on 2026-07-28, using evidence available as of 2026-07-28. Weights are domain-reasoned starting points, not values fitted to outcomes; calibration is deferred until a historical backtest exists to calibrate against.

Location

Estimated demand

none of this is a filed figure
Power capacityInferred

10.1 MW

5plausible range20.2

Assembled acreage x assumed power density, adjusted for stage.

What this assumes

Power density is an industry assumption, not a property of this site. Helios does not know the building footprint, rack density or how much of the assembled land will be built on.

stage
7
total acres
4.2
MW per acre low
1
MW per acre high
4
MW per acre likely
2
stage density multiplier
1.2
Cooling waterInferred

121,200 GPD

12,000plausible range484,800

Estimated power x assumed cooling water intensity.

What this assumes

Cooling type is not recorded in any source Helios ingests. A closed-loop or air-cooled design approaches zero water use; evaporative cooling can exceed a gallon per kWh. The band is wide because the practice is.

gal per kwh low
0.1
gal per kwh high
1
gal per kwh likely
0.5

Operator and ownership

Operator not established
TIERRA DC ASSETS LLCLLCPossible single-purpose entity
  • pass-through legal form (LLC)

Helios records the entity of record only. Shell-company indicators are flags for human review and do not constitute an attribution to any parent.

Parcels

APNAddressAcresDeed
123-31-001F2601 W BROADWAY RD4.202021-08-02

Infrastructure dependencies

Binary SubstationInferredLikely dedicated
828 m away · 69 kV · Salt River Project · match confidence 70%
Unnamed substationInferredLikely dedicated
1062 m away · 69 kV · match confidence 63%
Weiler SubstationInferredLikely dedicated
1125 m away · 69 kV · Salt River Project · match confidence 61%
Wilkins SubstationInferredLikely dedicated
1385 m away · 69 kV · Salt River Project · match confidence 53%
Unnamed substationInferred
1577 m away · 69 kV · match confidence 48%
Unnamed substationInferred
2648 m away · 69 kV · match confidence 16%

Dependencies are inferred from spatial proximity. A nearby substation makes a connection practical; it is not evidence that one exists.

Attribution

  • Parcel data courtesy of Maricopa County Assessor / Maricopa County GIS.
  • Power infrastructure data (c) OpenStreetMap contributors, ODbL.

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