MARION
SubstationTexas · BLUEBONNET ELECTRIC COOP, INC
At a glance
MARION is an electric transmission substation in Texas, on BLUEBONNET ELECTRIC COOP, INC's transmission network. It is classified as high-voltage (345 kv) and connects 11 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
Connected transmission lines
Lines terminating at or passing through this substation, by HIFLD line ID, highest voltage first.
| Line ID | Voltage | Owner | Status | Length |
|---|---|---|---|---|
| #308777 | 345 kV | BLUEBONNET ELECTRIC COOP, INC | IN SERVICE | 8.6 mi |
| #303875 | 345 kV | BLUEBONNET ELECTRIC COOP, INC | — | 14.3 mi |
| #304468 | 345 kV | GUADALUPE VALLEY ELEC COOP INC | IN SERVICE | 28.0 mi |
| #304852 | 345 kV | GUADALUPE VALLEY ELEC COOP INC | IN SERVICE | 16.2 mi |
| #308162 | 345 kV | BLUEBONNET ELECTRIC COOP, INC | IN SERVICE | 18.1 mi |
| #302682 | 138 kV | GUADALUPE VALLEY ELEC COOP INC | IN SERVICE | 4.5 mi |
| #303782 | 138 kV | GUADALUPE VALLEY ELEC COOP INC | IN SERVICE | 3.5 mi |
| #304040 | 138 kV | BLUEBONNET ELECTRIC COOP, INC | IN SERVICE | 0.5 mi |
| #307731 | 138 kV | BLUEBONNET ELECTRIC COOP, INC | IN SERVICE | 4.9 mi |
| #306141 | 69 kV | BLUEBONNET ELECTRIC COOP, INC | IN SERVICE | 0.5 mi |
Nearby datacenter candidate sites
Scored candidate sites within roughly 25 miles of MARION, 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 |
|---|---|---|---|---|---|---|---|
| CALAVERAS 345 SWITCHYARD | Substation-Adjacent | TX | Bexar County | 345 kV | 600 MW | 3.5 yrs | 70.0 |
| ARTHUR VON ROSENBERG | Substation-Adjacent | TX | Bexar County | 345 kV | 600 MW | 3.5 yrs | 68.9 |
| BROOKS FIELD | Substation-Adjacent | TX | Bexar County | 345 kV | 600 MW | 3.5 yrs | 68.6 |
| SKYLINE | Substation-Adjacent | TX | Bexar County | 345 kV | 600 MW | 3.5 yrs | 68.5 |
| EC Near W B Tuttle | Greenfield | TX | Bexar | — | — | 3.5 yrs | 68.1 |
| EC Near Tessman Road | Greenfield | TX | Bexar | — | — | 3.5 yrs | 67.4 |
| EC Near Mission Road | Greenfield | TX | Bexar | — | — | 3.5 yrs | 67.3 |
| MARION | Substation-Adjacent | TX | Guadalupe County | 345 kV | 600 MW | 3.5 yrs | 66.3 |
How does MARION compare with other substations in Texas?
Texas has 4,939 substation records in HIFLD, of which 1,426 carry a station name; the rest are unnamed tap points, risers and line ends. 198 named substations in the state are in MARION's 345–499 kV band (14% of named stations). 2 sit in a higher band. 200 named substations in Texas operate at 345 kV or above. The highest voltage recorded in the state is 500 kV, and the state median is 138 kV.
Who owns the transmission lines at MARION?
The 10 connected lines listed above are owned by BLUEBONNET ELECTRIC COOP, INC, GUADALUPE VALLEY ELEC COOP INC. Line voltages range from 69 kV to 345 kV. Their combined recorded length is about 99.2 miles.
How do candidate sites near MARION score?
The 8 highest-scoring candidate sites within about 25 miles range from 66 to 70 on the 0–100 DC Readiness scale. They fall in Bexar County, Bexar, Guadalupe County. The Texas average across 6,839 scored sites is 56.4. 3,635 of those Texas sites are classed as substation sites (candidate locations generated at an existing substation).
Frequently asked questions
What voltage is MARION substation?
MARION has a maximum voltage of 345 kV and a minimum of 69 kV. That places it in the 345–499 kV band. The median named US substation in this dataset is 115 kV, so MARION is above the national midpoint.
How many transmission lines connect to MARION substation?
11 transmission lines terminate at or pass through MARION in the HIFLD line data. The connected lines listed here run at 345 kV, 138 kV, 69 kV. Together the listed lines cover about 99.2 miles.
Who owns MARION substation?
HIFLD does not publish substation owners directly. Most of the transmission lines that end at MARION belong to BLUEBONNET ELECTRIC COOP, INC, and others to GUADALUPE VALLEY ELEC COOP INC. GridCensus derives this from the line data, so confirm ownership with the utility for anything contractual.
Where is MARION substation located?
MARION is in Texas at 29.6205, -98.1487. The datacenter candidate sites closest to it are in Bexar County, Bexar, Guadalupe County.
Are there datacenter candidate sites near MARION substation?
GridCensus lists at least 8 scored candidate sites within roughly 25 miles of MARION. The highest-scoring is CALAVERAS 345 SWITCHYARD at 70/100. Across Texas, the average DC Readiness score is 56.4.
Other 345 kV substations in Texas
- GREENS BAYOU 345· 21 lines
- ROYSE· 17 lines
- CEDAR BAYOU PLANT· 16 lines
- PH ROBINSON· 16 lines
- VENUS· 16 lines
- SKYLINE· 15 lines
- SOTEX5· 15 lines
- PARISH· 14 lines
- All named substations in Texas· 1,426 stations
- Datacenter candidate sites in Texas· 6,839 sites
- Brownfield and retired plant sites in Texas
- Substations by state
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, “MARION substation, Texas”, https://gridcensus.com/substations/texas/marion-3e65f3a0 (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 MARION substation, Texas 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.