TAP139457
SubstationMissouri · UNION ELECTRIC CO - (MO)
At a glance
TAP139457 is an electric transmission substation in Missouri, operated by UNION ELECTRIC CO - (MO). 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 |
|---|---|---|---|---|
| #122351 | 138 kV | UNION ELECTRIC CO - (MO) | IN SERVICE | 4.2 mi |
| #125896 | 138 kV | UNION ELECTRIC CO - (MO) | IN SERVICE | 0.1 mi |
| #128827 | 138 kV | UNION ELECTRIC CO - (MO) | IN SERVICE | 3.6 mi |
Nearby datacenter candidate sites
Scored candidate sites within roughly 25 miles of TAP139457, 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 |
|---|---|---|---|---|---|---|---|
| American Bottoms Solar Project | Brownfield | MO | St. Louis | 345 kV | 2 MW | 4.3 yrs | 69.4 |
| CAHOKIA | Substation-Adjacent | IL | St. Louis city | 345 kV | 600 MW | 4.8 yrs | 67.6 |
| MASON | Substation-Adjacent | MO | St. Louis County | 345 kV | 600 MW | 4.3 yrs | 67.3 |
| UNKNOWN117735 | Substation-Adjacent | MO | St. Louis city | 345 kV | 600 MW | 4.3 yrs | 67.0 |
| TAP139481 | Substation-Adjacent | IL | St. Louis city | 345 kV | 600 MW | 4.8 yrs | 66.6 |
| STALLINGS | Substation-Adjacent | IL | Madison County | 345 kV | 600 MW | 4.8 yrs | 66.5 |
| UNKNOWN117706 | Substation-Adjacent | MO | St. Louis County | 345 kV | 600 MW | 4.3 yrs | 66.2 |
| TYSON | Substation-Adjacent | MO | St. Louis County | 345 kV | 600 MW | 4.3 yrs | 66.1 |
Who owns the transmission lines at TAP139457?
The 3 connected lines listed above are owned by UNION ELECTRIC CO - (MO). Line voltages range from 138 kV to 138 kV. Their combined recorded length is about 8 miles.
How do candidate sites near TAP139457 score?
The 8 highest-scoring candidate sites within about 25 miles range from 66 to 69 on the 0–100 DC Readiness scale. They fall in St. Louis, St. Louis city, St. Louis County, Madison County. The Missouri average across 3,413 scored sites is 55.7. 1,002 of those Missouri sites are classed as substation sites (candidate locations generated at an existing substation).
Frequently asked questions
What voltage is TAP139457 substation?
TAP139457 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 TAP139457 is above the national midpoint.
How many transmission lines connect to TAP139457 substation?
3 transmission lines terminate at or pass through TAP139457 in the HIFLD line data. The connected lines listed here run at 138 kV. Together the listed lines cover about 8 miles.
Who owns TAP139457 substation?
HIFLD lists UNION ELECTRIC CO - (MO) as the operator of TAP139457.
Where is TAP139457 substation located?
TAP139457 is in Missouri at 38.5322, -90.3305. The datacenter candidate sites closest to it are in St. Louis, St. Louis city, St. Louis County.
Are there datacenter candidate sites near TAP139457 substation?
GridCensus lists at least 8 scored candidate sites within roughly 25 miles of TAP139457. The highest-scoring is American Bottoms Solar Project at 69/100. Across Missouri, the average DC Readiness score is 55.7.
More in Missouri
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, “TAP139457 substation, Missouri”, https://gridcensus.com/substations/missouri/tap139457-c3eb9026 (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 TAP139457 substation, Missouri 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.