Power Grid Proximity Screener — Lines, Substations & Power Plants Near Your Sites

Screens a list of sites (lat/lon) for grid access. For each one it finds the nearest in-service high-voltage transmission line (distance, voltage kV, class, owning utility), the nearest electric substation (distance, max voltage), and the nearest power plant (distance, capacity MW, fuel/type), counts how many of each fall within the search radius, and assigns a HIGH/MEDIUM/LOW grid-access tier you can sort a portfolio by. Built for data-center and renewable site selectors for whom power proximity is the gating constraint.

How it works

For every asset, the actor runs a bounding-box query against three DHS HIFLD Open (Homeland Infrastructure Foundation-Level Data) ArcGIS layers — Electric_Power_Transmission_Lines, Electric_Substations, and Power_Plants — then computes distances locally: point-to-polyline haversine for lines, point-to-point haversine for substations and plants. One combined row is emitted per asset. A bad coordinate or an upstream lines-layer failure produces an ERROR row for that asset only; a substation- or power-plant-layer hiccup just leaves those fields null and the rest of the row is returned. No API key, no login.

Line distance is reported in miles; substation and power-plant distances are in kilometres. Set includeSubstations or includePowerPlants to false to skip either layer.

Grid-access tier (editorial model)

Tier	Rule
HIGH	An existing line ≥ 230 kV within 2 miles
MEDIUM	Existing ≥ 115 kV within 2 miles, or ≥ 230 kV within 5 miles
LOW	Any existing line within the search radius
NONE	No existing line within the search radius
ERROR	Asset could not be screened (see error)

"Existing" means energized lines, excluding those whose HIFLD STATUS marks them under construction, proposed, or retired. HIFLD leaves the STATUS of most in-service lines as NOT AVAILABLE, so this screener treats NOT AVAILABLE and unlabeled lines as existing — a strict "IN SERVICE"-only filter would wrongly report NONE next to real 230 kV lines. The tier is a heuristic for ranking sites, not an interconnection or hosting-capacity study.

Example input

{
  "assets": [
    { "lat": 39.7392, "lon": -104.9903, "label": "Denver site" },
    { "lat": 33.4484, "lon": -112.0740, "label": "Phoenix site" }
  ],
  "radiusMiles": 5,
  "minVoltageKv": 115,
  "includeSubstations": true,
  "includePowerPlants": true
}

Output fields (one combined row per asset)

Field	Meaning
asset_label, asset_lat, asset_lon	Your site, echoed back
nearest_line_distance_miles	Miles to the nearest existing (energized) transmission line
nearest_line_voltage_kv	Its voltage in kV (null when HIFLD doesn't report it)
nearest_line_volt_class	HIFLD voltage class, e.g. 100-161, 345, UNDER 100
nearest_line_owner	Owning utility
nearest_line_status	Raw HIFLD status (NOT AVAILABLE = unspecified, not out of service)
lines_within_radius	Line count within radius (after the minVoltageKv filter)
lines_under_construction_within_radius	Of those, how many are flagged under construction
max_voltage_within_radius_kv	Highest line voltage within the radius
nearest_substation_name / _distance_km / _max_voltage	Nearest electric substation
substations_within_radius	Substation count within radius
nearest_power_plant_name / _distance_km / _fuel / _type / _capacity_mw	Nearest power plant (fuel e.g. NG, SUN, WND, COL; type is the NAICS generation class)
power_plants_within_radius	Power-plant count within radius
planned_line_nearby	Low-confidence, non-authoritative hint (opt-in; see FAQ)
grid_tier	HIGH / MEDIUM / LOW / NONE / ERROR
error, checked_at, source_url	Error message, run timestamp, HIFLD source layer

Substation & power plant proximity

On by default since v1.1 (includeSubstations / includePowerPlants, both true unless explicitly set to false). For every asset the actor also returns the nearest HIFLD electric substation and the nearest power plant, each with a distance, so you get one API call that answers "how close is transmission, a substation, and generation" instead of three separate lookups.

Who this is for:

• Data-center site selection — substation proximity (and its nearest_substation_max_voltage) is often a harder gating constraint than the transmission line itself, since interconnection usually happens at a substation, not a bare line crossing.
• Renewables & BESS interconnection pre-screening — ranking parcels by distance to both a substation (likely point of interconnection) and existing generation (an early signal of hosting-capacity headroom on that part of the grid) before commissioning a full interconnection study.

Example input (substation + power-plant screening explicitly on):

{
  "assets": [
    { "lat": 39.7392, "lon": -104.9903, "label": "Denver site" }
  ],
  "radiusMiles": 10,
  "includeSubstations": true,
  "includePowerPlants": true
}

Output fields added by this screen:

Field	Meaning
nearest_substation_name	Name of the closest electric substation within radius
nearest_substation_distance_km	Distance to that substation in km
nearest_substation_max_voltage	Substation's max voltage in kV
substations_within_radius	Count of substations within radius
nearest_power_plant_name	Name of the closest power plant within radius
nearest_power_plant_distance_km	Distance to that plant in km
nearest_power_plant_fuel	Primary fuel (e.g. NG, SUN, WND, COL)
nearest_power_plant_type	NAICS generation type
nearest_power_plant_capacity_mw	Operating capacity in MW
power_plants_within_radius	Count of power plants within radius

Set either flag to false to skip that layer and speed up large batch runs (fewer upstream queries per asset).

FAQ

Is there a distance to nearest electric substation API? Yes — every screened asset returns nearest_substation_distance_km, nearest_substation_name, and nearest_substation_max_voltage, sourced from HIFLD's Electric Substations layer, on by default.

Can I do substation proximity screening for data centers in bulk? Yes — submit up to 2,000 sites per run as assets, get back nearest substation, nearest power plant, nearest transmission line, and a HIGH/MEDIUM/LOW grid_tier for each, one row per site.

Does it tell me how close a candidate parcel is to existing generation? Yes — nearest_power_plant_distance_km, nearest_power_plant_capacity_mw, and nearest_power_plant_fuel report the closest power plant within the search radius, plus power_plants_within_radius for density.

Who uses it

• Data-center site selectors screening candidate parcels for proximity to 230 kV+ lines, substations, and generation before spending on interconnection studies.
• Solar, wind, and BESS developers ranking parcels by distance to transmission and the voltage class they can realistically tie into.
• EV-charging network planners verifying grid presence around candidate hubs.
• Land agents adding grid-access, nearest-substation, and nearest-power-plant columns to listing sheets.
• Energy analysts looking at line density, ownership, and fuel mix around a point.

Use as an MCP tool

A Pay-Per-Result API callable by AI agents through mcp.apify.com. Field-level output descriptions let an agent geocode candidate addresses, screen them, and rank by grid_tier, nearest_line_distance_miles, and nearest_substation_distance_km without glue code.

FAQ

Which sites can support a data center or battery project? Sort by grid_tier, then nearest_line_distance_miles and nearest_substation_distance_km. HIGH-tier sites have 230 kV+ in-service transmission within 2 miles, and a nearby substation is a strong interconnection signal.

Does it include planned transmission lines? Only as an opt-in, non-authoritative hint. HIFLD's planned-line layer is an editable scratch layer with geometry only (no owner/voltage/status), so it is not a reliable planned-line dataset. Set includePlanned: true to populate planned_line_nearby, and treat it as a weak signal.

Is the distance exact? Distances use haversine math against HIFLD's published geometries, accurate to a few feet at screening scales.

Where does the data come from? DHS HIFLD Open ArcGIS: the Electric_Power_Transmission_Lines, Electric_Substations, and Power_Plants FeatureServer layers (public, keyless). This is advisory data — confirm with the utility before committing capital.

How is it billed? One result per screened asset (one combined row covering lines, substations, and plants).