HERLEMAN
SubstationIllinois
HERLEMAN is an electric transmission substation in Illinois. It is classified as high-voltage (345 kv) and connects 5 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 & operation
Operator not catalogued for this substation.
Connected transmission lines
Lines terminating at or passing through this substation, by HIFLD line ID, highest voltage first.
| Line ID | Voltage | Owner | Status | Length |
|---|---|---|---|---|
| #41500 | 345 kV | — | IN SERVICE | 14.9 mi |
| #41501 | 345 kV | — | IN SERVICE | 46.6 mi |
| #40115 | 138 kV | — | IN SERVICE | 2.5 mi |
| #41486 | 138 kV | — | IN SERVICE | 2.4 mi |
| #41490 | 138 kV | — | IN SERVICE | 15.0 mi |
Nearby datacenter candidate sites
Scored candidate sites within roughly 25 miles of HERLEMAN, 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 |
|---|---|---|---|---|---|---|---|
| MAYWOOD | Substation-Adjacent | MO | Marion County | 345 kV | 600 MW | 4.6 yrs | 70.0 |
| PALMYRA | Substation-Adjacent | MO | Marion County | 345 kV | 600 MW | 1.4 yrs | 69.6 |
| HERLEMAN | Substation-Adjacent | IL | Adams County | 345 kV | 600 MW | 4.6 yrs | 69.5 |
| TAP140530 | Substation-Adjacent | MO | Ralls County | 345 kV | 600 MW | 1.4 yrs | 69.2 |
| PALMYRA | Substation-Adjacent | MO | Marion County | 161 kV | 100 MW | 1.4 yrs | 66.9 |
| UNKNOWN122774 | Substation-Adjacent | IL | Adams County | 138 kV | 100 MW | 4.6 yrs | 66.6 |
| Greenfield (TAP140530 - TAP140541) | Greenfield | MO | Ralls County | 345 kV | 600 MW | 1.4 yrs | 65.6 |
| TAP140528 | Substation-Adjacent | MO | Marion County | 161 kV | 100 MW | 1.4 yrs | 64.8 |
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
This page shows a public slice of the GridCensus dataset for HERLEMAN substation, Illinois. Pro and Enterprise plans unlock the full 164,098-site catalog, raw sub-scores, parcel ownership, interconnection-queue detail, saved searches, and programmatic API access.