TAP139487
SubstationIllinois · AMEREN ILLINOIS COMPANY
At a glance
TAP139487 is an electric transmission substation in Illinois, on AMEREN ILLINOIS COMPANY's transmission network. It is classified as sub-transmission (138 kv) 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
Connected transmission lines
Lines terminating at or passing through this substation, by HIFLD line ID, highest voltage first.
| Line ID | Voltage | Owner | Status | Length |
|---|---|---|---|---|
| #104265 | 138 kV | AMEREN ILLINOIS COMPANY | IN SERVICE | 10.3 mi |
| #104914 | 138 kV | AMEREN ILLINOIS COMPANY | IN SERVICE | 9.3 mi |
| #115372 | 138 kV | AMEREN ILLINOIS COMPANY | IN SERVICE | 0.0 mi |
Nearby datacenter candidate sites
Scored candidate sites within roughly 25 miles of TAP139487, 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 |
|---|---|---|---|---|---|---|---|
| PRAIRIE STATE STATION | Substation-Adjacent | IL | Washington County | 345 kV | 600 MW | 4.8 yrs | 61.3 |
| PINCKNEYVILLE STATION | Substation-Adjacent | IL | Perry County | 230 kV | 300 MW | 4.8 yrs | 59.9 |
| UNKNOWN122403 | Substation-Adjacent | IL | Washington County | 230 kV | 300 MW | 4.8 yrs | 59.3 |
| UNKNOWN122131 | Substation-Adjacent | IL | Perry County | 230 kV | 300 MW | 4.8 yrs | 59.1 |
| EC Near Highland | Greenfield | IL | Madison | — | — | 4.8 yrs | 58.7 |
| EC Near Highland | Greenfield | IL | Madison | — | — | 4.8 yrs | 57.9 |
| EC Near Breese | Greenfield | IL | Clinton | — | — | 4.8 yrs | 57.5 |
| EC Coal Perry County | Greenfield | IL | Perry County | — | — | 4.8 yrs | 57.5 |
Who owns the transmission lines at TAP139487?
The 3 connected lines listed above are owned by AMEREN ILLINOIS COMPANY. Line voltages range from 138 kV to 138 kV. Their combined recorded length is about 19.6 miles.
How do candidate sites near TAP139487 score?
The 8 highest-scoring candidate sites within about 25 miles range from 58 to 61 on the 0–100 DC Readiness scale. They fall in Washington County, Perry County, Madison, Clinton. The Illinois average across 3,641 scored sites is 54.3. 795 of those Illinois sites are classed as substation sites (candidate locations generated at an existing substation).
Frequently asked questions
What voltage is TAP139487 substation?
TAP139487 has a maximum voltage of 138 kV. That places it in the 115–229 kV band. The median named US substation in this dataset is 115 kV, so TAP139487 is above the national midpoint.
How many transmission lines connect to TAP139487 substation?
3 transmission lines terminate at or pass through TAP139487 in the HIFLD line data. The connected lines listed here run at 138 kV. Together the listed lines cover about 19.6 miles.
Who owns TAP139487 substation?
HIFLD does not publish substation owners directly. Most of the transmission lines that end at TAP139487 belong to AMEREN ILLINOIS COMPANY. GridCensus derives this from the line data, so confirm ownership with the utility for anything contractual.
Where is TAP139487 substation located?
TAP139487 is in Illinois at 38.3776, -89.3715. The datacenter candidate sites closest to it are in Washington County, Perry County, Madison.
Are there datacenter candidate sites near TAP139487 substation?
GridCensus lists at least 8 scored candidate sites within roughly 25 miles of TAP139487. The highest-scoring is PRAIRIE STATE STATION at 61/100. Across Illinois, the average DC Readiness score is 54.3.
More in Illinois
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, “TAP139487 substation, Illinois”, https://gridcensus.com/substations/illinois/tap139487-25513360 (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 TAP139487 substation, Illinois 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.