MERCER
SubstationIllinois · AMEREN ILLINOIS COMPANY
At a glance
MERCER is an electric transmission substation in Illinois, on AMEREN ILLINOIS COMPANY's transmission network. It is classified as sub-transmission (138 kv) and connects 2 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 |
|---|---|---|---|---|
| #112022 | 161 kV | — | IN SERVICE | 15.0 mi |
| #161956 | 161 kV | AMEREN ILLINOIS COMPANY | IN SERVICE | 17.7 mi |
Nearby datacenter candidate sites
Scored candidate sites within roughly 25 miles of MERCER, 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 |
|---|---|---|---|---|---|---|---|
| UNKNOWN131382 | Substation-Adjacent | IA | Scott County | 345 kV | 600 MW | 4.3 yrs | 68.3 |
| UNKNOWN131604 | Substation-Adjacent | IA | Scott County | 345 kV | 600 MW | 4.3 yrs | 67.8 |
| UNKNOWN131605 | Substation-Adjacent | IA | Rock Island County | 345 kV | 600 MW | 4.3 yrs | 67.3 |
| SUB 39 | Substation-Adjacent | IL | Rock Island County | 345 kV | 600 MW | 4.8 yrs | 67.2 |
| OAK GROVE | Substation-Adjacent | IL | Rock Island County | 345 kV | 600 MW | 4.8 yrs | 66.6 |
| EC Coal Scott County | Greenfield | IA | Scott County | — | — | 4.3 yrs | 65.8 |
| EC Near Riverside | Greenfield | IA | Scott | — | — | 4.3 yrs | 65.4 |
| EC Near Riverside | Greenfield | IA | Scott | — | — | 4.3 yrs | 65.0 |
How does MERCER compare with other substations in Illinois?
Illinois has 1,986 substation records in HIFLD, of which 209 carry a station name; the rest are unnamed tap points, risers and line ends. 90 named substations in the state are in MERCER's 115–229 kV band (43% of named stations). 95 sit in a higher band. 92 named substations in Illinois operate at 345 kV or above. The highest voltage recorded in the state is 765 kV, and the state median is 161 kV.
Who owns the transmission lines at MERCER?
The 2 connected lines listed above are owned by AMEREN ILLINOIS COMPANY. Line voltages range from 161 kV to 161 kV. Their combined recorded length is about 32.8 miles.
How do candidate sites near MERCER score?
The 8 highest-scoring candidate sites within about 25 miles range from 65 to 68 on the 0–100 DC Readiness scale. They fall in Scott County, Rock Island County, Scott. 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 MERCER substation?
MERCER has a maximum voltage of 161 kV. That places it in the 115–229 kV band. The median named US substation in this dataset is 115 kV, so MERCER is above the national midpoint.
How many transmission lines connect to MERCER substation?
2 transmission lines terminate at or pass through MERCER in the HIFLD line data. The connected lines listed here run at 161 kV. Together the listed lines cover about 32.8 miles.
Who owns MERCER substation?
HIFLD does not publish substation owners directly. Most of the transmission lines that end at MERCER belong to AMEREN ILLINOIS COMPANY. GridCensus derives this from the line data, so confirm ownership with the utility for anything contractual.
Where is MERCER substation located?
MERCER is in Illinois at 41.2040, -90.4622. The datacenter candidate sites closest to it are in Scott County, Rock Island County, Scott.
Are there datacenter candidate sites near MERCER substation?
GridCensus lists at least 8 scored candidate sites within roughly 25 miles of MERCER. The highest-scoring is UNKNOWN131382 at 68/100. Across Illinois, the average DC Readiness score is 54.3.
Other 161 kV substations 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, “MERCER substation, Illinois”, https://gridcensus.com/substations/illinois/mercer-ce5a52d5 (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 MERCER 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.