TAP302778
SubstationArizona · GRAHAM COUNTY ELECTRIC COOPERATIVE INCORPORATED
At a glance
TAP302778 is an electric transmission substation in Arizona, on GRAHAM COUNTY ELECTRIC COOPERATIVE INCORPORATED's transmission network. It is classified as unclassified and connects 3 transmission lines. Substation proximity is one of the strongest speed-to-power signals for siting a datacenter — interconnection distance to an energized, high-voltage bus is often the binding constraint on time-to-energization.
Voltage & classification
Ownership
Connected transmission lines
Lines terminating at or passing through this substation, by HIFLD line ID, highest voltage first.
| Line ID | Voltage | Owner | Status | Length |
|---|---|---|---|---|
| #302225 | — | GRAHAM COUNTY ELECTRIC COOPERATIVE INCORPORATED | IN SERVICE | 1.2 mi |
| #303082 | — | GRAHAM COUNTY ELECTRIC COOPERATIVE INCORPORATED | IN SERVICE | 6.2 mi |
| #305536 | — | GRAHAM COUNTY ELECTRIC COOPERATIVE INCORPORATED | IN SERVICE | 0.9 mi |
Nearby datacenter candidate sites
Scored candidate sites within roughly 25 miles of TAP302778, ranked by DC Readiness. Sites this close to an energized substation carry a strong speed-to-power advantage.
| Site | Type | State | County | Voltage | Capacity | Queue wait | Score |
|---|---|---|---|---|---|---|---|
| DOS CONDADOS | Substation-Adjacent | AZ | Graham County | 230 kV | 300 MW | 3.5 yrs | 55.5 |
| HACKBERRY | Substation-Adjacent | AZ | Graham County | 230 kV | 300 MW | 3.5 yrs | 55.2 |
| EC FFE Graham County | Greenfield | AZ | Graham County | — | — | 3.5 yrs | 53.7 |
| UNKNOWN309814 | Substation-Adjacent | AZ | Greenlee County | 115 kV | 100 MW | 3.5 yrs | 51.0 |
| OZ Graham | Greenfield | AZ | Graham | — | — | 3.5 yrs | 50.4 |
| UNKNOWN300824 | Substation-Adjacent | AZ | Graham County | 69 kV | 50 MW | 3.5 yrs | 49.5 |
| Greenfield (TAP306867 - None) | Greenfield | AZ | Graham County | 230 kV | 300 MW | 3.5 yrs | 49.0 |
| Greenfield (DOS CONDADOS - TAP306867) | Greenfield | AZ | Graham County | 230 kV | 300 MW | 3.5 yrs | 48.9 |
Who owns the transmission lines at TAP302778?
The 3 connected lines listed above are owned by GRAHAM COUNTY ELECTRIC COOPERATIVE INCORPORATED. Their combined recorded length is about 8.3 miles.
How do candidate sites near TAP302778 score?
The 8 highest-scoring candidate sites within about 25 miles range from 49 to 56 on the 0–100 DC Readiness scale. They fall in Graham County, Greenlee County, Graham. The Arizona average across 3,816 scored sites is 48.5. 614 of those Arizona sites are classed as substation sites (candidate locations generated at an existing substation).
Frequently asked questions
How many transmission lines connect to TAP302778 substation?
3 transmission lines terminate at or pass through TAP302778 in the HIFLD line data. Together the listed lines cover about 8.3 miles.
Who owns TAP302778 substation?
HIFLD does not publish substation owners directly. Most of the transmission lines that end at TAP302778 belong to GRAHAM COUNTY ELECTRIC COOPERATIVE INCORPORATED. GridCensus derives this from the line data, so confirm ownership with the utility for anything contractual.
Where is TAP302778 substation located?
TAP302778 is in Arizona at 32.9256, -109.6899. The datacenter candidate sites closest to it are in Graham County, Greenlee County, Graham.
Are there datacenter candidate sites near TAP302778 substation?
GridCensus lists at least 8 scored candidate sites within roughly 25 miles of TAP302778. The highest-scoring is DOS CONDADOS at 56/100. Across Arizona, the average DC Readiness score is 48.5.
More in Arizona
About this data
Source: HIFLD Electric Substations and Transmission Lines (U.S. Department of Homeland Security), as published June 29, 2026. See the methodology for how records are matched, cleaned and scored.
Cite as: GridCensus, “TAP302778 substation, Arizona”, https://gridcensus.com/substations/arizona/tap302778-ba01a062 (data as of June 29, 2026).
Dataset updated . Screening estimates derived from public data sources.
Substation attributes are derived from public HIFLD / EIA infrastructure data and may lag real-world upgrades or retirements. Voltage and connected-line counts are screening figures — confirm available capacity and interconnection terms directly with the operating utility and ISO.
Go deeper than the public screen
Every site and score for TAP302778 substation, Arizona is free to browse. Pro adds Watchtower on 25 sites, alerts when new candidate sites, datacenters or interconnection-queue requests appear in your markets, score and capacity history, and CSV export. Enterprise adds team seats, weekly data files for all 147,272 sites, the REST API and an MCP server for AI tools.