HOLTSVILLE MGU
SubstationNew York · LONG ISLAND POWER AUTHORITY
At a glance
HOLTSVILLE MGU is an electric transmission substation in New York, on LONG ISLAND POWER AUTHORITY's transmission network. It is classified as distribution (69–115 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
Connected transmission lines
Lines terminating at or passing through this substation, by HIFLD line ID, highest voltage first.
| Line ID | Voltage | Owner | Status | Length |
|---|---|---|---|---|
| #143403 | 138 kV | LONG ISLAND POWER AUTHORITY | — | 0.1 mi |
| #135075 | 69 kV | LONG ISLAND POWER AUTHORITY | IN SERVICE | 2.6 mi |
| #109477 | 69 kV | LONG ISLAND POWER AUTHORITY | — | 0.0 mi |
| #107362 | 69 kV | LONG ISLAND POWER AUTHORITY | IN SERVICE | 6.6 mi |
| #138233 | — | LONG ISLAND POWER AUTHORITY | IN SERVICE | 0.0 mi |
| #102289 | — | LONG ISLAND POWER AUTHORITY | IN SERVICE | 0.2 mi |
| #144532 | — | LONG ISLAND POWER AUTHORITY | IN SERVICE | 0.2 mi |
| #112457 | — | LONG ISLAND POWER AUTHORITY | IN SERVICE | 0.2 mi |
| #124088 | — | LONG ISLAND POWER AUTHORITY | IN SERVICE | 0.2 mi |
| #125798 | — | LONG ISLAND POWER AUTHORITY | IN SERVICE | 0.4 mi |
Nearby datacenter candidate sites
Scored candidate sites within roughly 25 miles of HOLTSVILLE MGU, 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 |
|---|---|---|---|---|---|---|---|
| BRIDGEPORT RESCO | Substation-Adjacent | CT | Greater Bridgeport Planning Region | 345 kV | 600 MW | 4.3 yrs | 71.7 |
| DEVON | Substation-Adjacent | CT | Greater Bridgeport Planning Region | 115 kV | 100 MW | 4.3 yrs | 65.0 |
| TAP141012 | Substation-Adjacent | NY | Nassau County | 138 kV | 100 MW | 4.3 yrs | 63.3 |
| NORWALK | Substation-Adjacent | CT | Western Connecticut Planning Region | 115 kV | 100 MW | 4.3 yrs | 63.3 |
| UNKNOWN172510 | Substation-Adjacent | CT | Greater Bridgeport Planning Region | 115 kV | 100 MW | 4.3 yrs | 63.3 |
| NORWALK HARBOR | Substation-Adjacent | CT | Greater Bridgeport Planning Region | 115 kV | 100 MW | 4.3 yrs | 63.3 |
| COMPO | Substation-Adjacent | CT | Greater Bridgeport Planning Region | 115 kV | 100 MW | 4.3 yrs | 63.3 |
| FLAX HILL | Substation-Adjacent | CT | Western Connecticut Planning Region | 115 kV | 100 MW | 4.3 yrs | 63.2 |
How does HOLTSVILLE MGU compare with other substations in New York?
New York has 2,777 substation records in HIFLD, of which 570 carry a station name; the rest are unnamed tap points, risers and line ends. 80 named substations in the state are in HOLTSVILLE MGU's 69–114 kV band (14% of named stations). 343 sit in a higher band. 56 named substations in New York operate at 345 kV or above. The highest voltage recorded in the state is 765 kV, and the state median is 115 kV.
Who owns the transmission lines at HOLTSVILLE MGU?
The 10 connected lines listed above are owned by LONG ISLAND POWER AUTHORITY. Line voltages range from 69 kV to 138 kV. Their combined recorded length is about 10.6 miles.
How do candidate sites near HOLTSVILLE MGU score?
The 8 highest-scoring candidate sites within about 25 miles range from 63 to 72 on the 0–100 DC Readiness scale. They fall in Greater Bridgeport Planning Region, Nassau County, Western Connecticut Planning Region. The New York average across 2,980 scored sites is 54. 844 of those New York sites are classed as substation sites (candidate locations generated at an existing substation).
Frequently asked questions
What voltage is HOLTSVILLE MGU substation?
HOLTSVILLE MGU has a maximum voltage of 69 kV. That places it in the 69–114 kV band. The median named US substation in this dataset is 115 kV, so HOLTSVILLE MGU is below the national midpoint.
How many transmission lines connect to HOLTSVILLE MGU substation?
5 transmission lines terminate at or pass through HOLTSVILLE MGU in the HIFLD line data. The connected lines listed here run at 138 kV, 69 kV. Together the listed lines cover about 10.6 miles.
Who owns HOLTSVILLE MGU substation?
HIFLD does not publish substation owners directly. Most of the transmission lines that end at HOLTSVILLE MGU belong to LONG ISLAND POWER AUTHORITY. GridCensus derives this from the line data, so confirm ownership with the utility for anything contractual.
Where is HOLTSVILLE MGU substation located?
HOLTSVILLE MGU is in New York at 40.8172, -73.0646. The datacenter candidate sites closest to it are in Greater Bridgeport Planning Region, Nassau County, Western Connecticut Planning Region.
Are there datacenter candidate sites near HOLTSVILLE MGU substation?
GridCensus lists at least 8 scored candidate sites within roughly 25 miles of HOLTSVILLE MGU. The highest-scoring is BRIDGEPORT RESCO at 72/100. Across New York, the average DC Readiness score is 54.
Other 69 kV substations in New York
- GLENWOOD LANDING· 9 lines
- BRENTWOOD· 8 lines
- FAR ROCKAWAY· 7 lines
- SYOSSET· 6 lines
- WEST YAPHANK· 5 lines
- BRIDGEHAMPTON· 4 lines
- BRIGHTWATERS· 4 lines
- EAST HAMPTON· 4 lines
- All named substations in New York· 570 stations
- Datacenter candidate sites in New York· 2,980 sites
- Brownfield and retired plant sites in New York
- 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, “HOLTSVILLE MGU substation, New York”, https://gridcensus.com/substations/new-york/holtsville-mgu-dcbdf887 (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 HOLTSVILLE MGU substation, New York 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.