ROCKVILLE
SubstationMaryland · POTOMAC ELECTRIC POWER CO
At a glance
ROCKVILLE is an electric transmission substation in Maryland, on POTOMAC ELECTRIC POWER CO's transmission network. It is classified as unclassified and connects 0 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 |
|---|---|---|---|---|
| #176547 | — | POTOMAC ELECTRIC POWER CO | — | 6.2 mi |
| #176551 | — | POTOMAC ELECTRIC POWER CO | — | 3.0 mi |
Nearby datacenter candidate sites
Scored candidate sites within roughly 25 miles of ROCKVILLE, 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 |
|---|---|---|---|---|---|---|---|
| GOOSE CREEK | Substation-Adjacent | VA | Loudoun County | 500 kV | 1,000 MW | 5.1 yrs | 69.9 |
| CLIFTON | Substation-Adjacent | VA | Manassas Park city | 500 kV | 1,000 MW | 5.1 yrs | 69.6 |
| OX | Substation-Adjacent | VA | Fairfax County | 500 kV | 1,000 MW | 5.1 yrs | 69.0 |
| CANNON BRANCH | Substation-Adjacent | VA | Manassas city | 230 kV | 300 MW | 5.1 yrs | 67.1 |
| BURCHES HILL | Substation-Adjacent | MD | Prince George's County | 500 kV | 1,000 MW | 5.3 yrs | 66.9 |
| BATTERY HEIGHTS DP | Substation-Adjacent | VA | Manassas city | 230 kV | 300 MW | 5.1 yrs | 66.8 |
| DULLES | Substation-Adjacent | VA | Fairfax city | 230 kV | 300 MW | 5.1 yrs | 66.8 |
| CLOVER HILL | Substation-Adjacent | VA | Prince William County | 230 kV | 300 MW | 5.1 yrs | 66.8 |
Who owns the transmission lines at ROCKVILLE?
The 2 connected lines listed above are owned by POTOMAC ELECTRIC POWER CO. Their combined recorded length is about 9.2 miles.
How do candidate sites near ROCKVILLE score?
The 8 highest-scoring candidate sites within about 25 miles range from 67 to 70 on the 0–100 DC Readiness scale. They fall in Loudoun County, Manassas Park city, Fairfax County, Manassas city. The Maryland average across 1,031 scored sites is 52.9. 314 of those Maryland sites are classed as substation sites (candidate locations generated at an existing substation).
Frequently asked questions
How many transmission lines connect to ROCKVILLE substation?
0 transmission lines terminate at or pass through ROCKVILLE in the HIFLD line data. Together the listed lines cover about 9.2 miles.
Who owns ROCKVILLE substation?
HIFLD does not publish substation owners directly. Most of the transmission lines that end at ROCKVILLE belong to POTOMAC ELECTRIC POWER CO. GridCensus derives this from the line data, so confirm ownership with the utility for anything contractual.
Where is ROCKVILLE substation located?
ROCKVILLE is in Maryland at 39.0822, -77.1433. The datacenter candidate sites closest to it are in Loudoun County, Manassas Park city, Fairfax County.
Are there datacenter candidate sites near ROCKVILLE substation?
GridCensus lists at least 8 scored candidate sites within roughly 25 miles of ROCKVILLE. The highest-scoring is GOOSE CREEK at 70/100. Across Maryland, the average DC Readiness score is 52.9.
More in Maryland
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, “ROCKVILLE substation, Maryland”, https://gridcensus.com/substations/maryland/rockville-88b919b5 (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 ROCKVILLE substation, Maryland 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.