TAP137877
SubstationIllinois · COMMONWEALTH EDISON CO
At a glance
TAP137877 is an electric transmission substation in Illinois, on COMMONWEALTH EDISON CO'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 |
|---|---|---|---|---|
| #104057 | 138 kV | COMMONWEALTH EDISON CO | IN SERVICE | 0.3 mi |
| #111585 | 138 kV | COMMONWEALTH EDISON CO | IN SERVICE | 3.9 mi |
| #143969 | 138 kV | COMMONWEALTH EDISON CO | IN SERVICE | 17.1 mi |
Nearby datacenter candidate sites
Scored candidate sites within roughly 25 miles of TAP137877, 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 |
|---|---|---|---|---|---|---|---|
| BYRON | Substation-Adjacent | IL | Ogle County | 345 kV | 600 MW | 4.8 yrs | 64.3 |
| TAP137909 | Substation-Adjacent | IL | Winnebago County | 345 kV | 600 MW | 4.8 yrs | 63.5 |
| EC FFE Carroll County | Greenfield | IL | Carroll County | — | — | 4.8 yrs | 60.3 |
| OZ Green | Greenfield | WI | Green | — | — | 4.3 yrs | 59.6 |
| ALBANY | Substation-Adjacent | WI | Green County | 138 kV | 100 MW | 4.3 yrs | 59.2 |
| NORTH MONROE | Substation-Adjacent | WI | Green County | 138 kV | 100 MW | 4.3 yrs | 59.0 |
| EC Near Argyle | Greenfield | WI | Lafayette | — | — | 4.3 yrs | 58.9 |
| EC Near Argyle | Greenfield | WI | Lafayette | — | — | 4.3 yrs | 58.9 |
Who owns the transmission lines at TAP137877?
The 3 connected lines listed above are owned by COMMONWEALTH EDISON CO. Line voltages range from 138 kV to 138 kV. Their combined recorded length is about 21.3 miles.
How do candidate sites near TAP137877 score?
The 8 highest-scoring candidate sites within about 25 miles range from 59 to 64 on the 0–100 DC Readiness scale. They fall in Ogle County, Winnebago County, Carroll County, Green. 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 TAP137877 substation?
TAP137877 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 TAP137877 is above the national midpoint.
How many transmission lines connect to TAP137877 substation?
3 transmission lines terminate at or pass through TAP137877 in the HIFLD line data. The connected lines listed here run at 138 kV. Together the listed lines cover about 21.3 miles.
Who owns TAP137877 substation?
HIFLD does not publish substation owners directly. Most of the transmission lines that end at TAP137877 belong to COMMONWEALTH EDISON CO. GridCensus derives this from the line data, so confirm ownership with the utility for anything contractual.
Where is TAP137877 substation located?
TAP137877 is in Illinois at 42.3160, -89.6195. The datacenter candidate sites closest to it are in Ogle County, Winnebago County, Carroll County.
Are there datacenter candidate sites near TAP137877 substation?
GridCensus lists at least 8 scored candidate sites within roughly 25 miles of TAP137877. The highest-scoring is BYRON at 64/100. 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, “TAP137877 substation, Illinois”, https://gridcensus.com/substations/illinois/tap137877-980f63b3 (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 TAP137877 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.