TAP159691
SubstationSouth Dakota · NORTHWESTERN ENERGY
At a glance
TAP159691 is an electric transmission substation in South Dakota, on NORTHWESTERN ENERGY's transmission network. It is classified as sub-transmission (115 kv) and connects 3 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 |
|---|---|---|---|---|
| #161799 | 115 kV | NORTHWESTERN ENERGY | IN SERVICE | 13.9 mi |
| #161800 | 115 kV | NORTHWESTERN ENERGY | IN SERVICE | 0.0 mi |
| #161801 | 115 kV | NORTHWESTERN ENERGY | IN SERVICE | 20.8 mi |
Nearby datacenter candidate sites
Scored candidate sites within roughly 25 miles of TAP159691, 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 |
|---|---|---|---|---|---|---|---|
| TAP159616 | Substation-Adjacent | SD | Day County | 115 kV | 100 MW | 4.3 yrs | 57.9 |
| UNKNOWN159679 | Substation-Adjacent | SD | Day County | 115 kV | 100 MW | 4.3 yrs | 57.9 |
| EC Near Webster IC | Greenfield | SD | Day | — | — | 4.3 yrs | 57.8 |
| UNKNOWN131133 | Substation-Adjacent | SD | Day County | 115 kV | 100 MW | 4.3 yrs | 57.7 |
| TAP159543 | Substation-Adjacent | SD | Day County | 115 kV | 100 MW | 4.3 yrs | 57.6 |
| TAP159554 | Substation-Adjacent | SD | Day County | 115 kV | 100 MW | 4.3 yrs | 57.5 |
| 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 |
Who owns the transmission lines at TAP159691?
The 3 connected lines listed above are owned by NORTHWESTERN ENERGY. Line voltages range from 115 kV to 115 kV. Their combined recorded length is about 34.8 miles.
How do candidate sites near TAP159691 score?
The 8 highest-scoring candidate sites within about 25 miles range from 57 to 58 on the 0–100 DC Readiness scale. They fall in Day County, Day, Clark 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
What voltage is TAP159691 substation?
TAP159691 has a maximum voltage of 115 kV. That places it in the 115–229 kV band. The median named US substation in this dataset is 115 kV, so TAP159691 is at the national midpoint.
How many transmission lines connect to TAP159691 substation?
3 transmission lines terminate at or pass through TAP159691 in the HIFLD line data. The connected lines listed here run at 115 kV. Together the listed lines cover about 34.8 miles.
Who owns TAP159691 substation?
HIFLD does not publish substation owners directly. Most of the transmission lines that end at TAP159691 belong to NORTHWESTERN ENERGY. GridCensus derives this from the line data, so confirm ownership with the utility for anything contractual.
Where is TAP159691 substation located?
TAP159691 is in South Dakota at 45.0937, -97.6368. The datacenter candidate sites closest to it are in Day County, Day, Clark County.
Are there datacenter candidate sites near TAP159691 substation?
GridCensus lists at least 8 scored candidate sites within roughly 25 miles of TAP159691. The highest-scoring is TAP159616 at 58/100. 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, “TAP159691 substation, South Dakota”, https://gridcensus.com/substations/south-dakota/tap159691-5804cad4 (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 TAP159691 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.