TAP159678
SubstationSouth Dakota · NORTHWESTERN ENERGY
At a glance
TAP159678 is an electric transmission substation in South Dakota, on NORTHWESTERN ENERGY's transmission network. It is classified as unclassified and connects 1 transmission line. 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 |
|---|---|---|---|---|
| #161805 | — | NORTHWESTERN ENERGY | IN SERVICE | 5.0 mi |
Nearby datacenter candidate sites
Scored candidate sites within roughly 25 miles of TAP159678, 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 |
|---|---|---|---|---|---|---|---|
| UNKNOWN131209 | Substation-Adjacent | SD | Clark County | 230 kV | 300 MW | 4.3 yrs | 61.9 |
| TAP143513 | Substation-Adjacent | SD | Day County | 115 kV | 100 MW | 4.3 yrs | 57.4 |
| UNKNOWN159689 | Substation-Adjacent | SD | Clark County | 115 kV | 100 MW | 4.3 yrs | 57.4 |
| TAP159691 | Substation-Adjacent | SD | Clark County | 115 kV | 100 MW | 4.3 yrs | 56.9 |
| UNKNOWN159687 | Substation-Adjacent | SD | Clark County | 115 kV | 100 MW | 4.3 yrs | 56.9 |
| UNKNOWN131132 | Substation-Adjacent | SD | Day County | 115 kV | 100 MW | 4.3 yrs | 56.4 |
| UNKNOWN159474 | Substation-Adjacent | SD | Clark County | 69 kV | 50 MW | 4.3 yrs | 56.0 |
| TAP159473 | Substation-Adjacent | SD | Kingsbury County | 69 kV | 50 MW | 4.3 yrs | 55.0 |
Who owns the transmission lines at TAP159678?
The 1 connected line listed above is owned by NORTHWESTERN ENERGY. Their combined recorded length is about 5 miles.
How do candidate sites near TAP159678 score?
The 8 highest-scoring candidate sites within about 25 miles range from 55 to 62 on the 0–100 DC Readiness scale. They fall in Clark County, Day County, Kingsbury County. The South Dakota average across 1,151 scored sites is 54.7. 477 of those South Dakota sites are classed as substation sites (candidate locations generated at an existing substation).
Frequently asked questions
How many transmission lines connect to TAP159678 substation?
1 transmission line terminate at or pass through TAP159678 in the HIFLD line data. Together the listed lines cover about 5 miles.
Who owns TAP159678 substation?
HIFLD does not publish substation owners directly. Most of the transmission lines that end at TAP159678 belong to NORTHWESTERN ENERGY. GridCensus derives this from the line data, so confirm ownership with the utility for anything contractual.
Where is TAP159678 substation located?
TAP159678 is in South Dakota at 44.9064, -97.7996. The datacenter candidate sites closest to it are in Clark County, Day County, Kingsbury County.
Are there datacenter candidate sites near TAP159678 substation?
GridCensus lists at least 8 scored candidate sites within roughly 25 miles of TAP159678. The highest-scoring is UNKNOWN131209 at 62/100. Across South Dakota, the average DC Readiness score is 54.7.
More in South Dakota
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, “TAP159678 substation, South Dakota”, https://gridcensus.com/substations/south-dakota/tap159678-186e78c9 (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 TAP159678 substation, South Dakota 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.