ISTS Hosting Capacity Atlas

Overview

Five endpoints turn the substation graph into a queryable API. The headroom call is the atomic unit; everything else composes from it.

Authentication

X-API-Key header, Enterprise tier. See energymap.in/pricing.

GET /v1/substations/{id}/headroom

curl https://api.energymap.in/v1/substations/sub-NRLDC-1023/headroom \
  -H 'X-API-Key: $KEY'

{
  "substation_id": "sub-NRLDC-1023",
  "name": "Bhadla 220kV",
  "voltage_kv": 220,
  "today_headroom_mw": 280,
  "queued_mw": 150,
  "expected_clearance_months": { "p50": 16, "p90": 22 },
  "y3_curtailment": { "p50": 0.08, "p90": 0.14 },
  "confidence": 0.83,
  "ies_tsp": { "schema_version": "0.5", "conforms": true },
  "sources": [
    { "type": "ctuil_loa", "id": "CTUIL/LOA/2025/4123" },
    { "type": "rldc_outage", "id": "NRLDC/OUT/2026-Q1" }
  ]
}

GET /v1/queue/depth/{region}

Ranked queue for a region, with developer and technology metadata.

POST /v1/sites/screen

Send coordinate or polygon, target capacity, and technology. Returns ranked candidate substations with headroom, queue depth, distance, terrain class, and district-level open-access economics for the load you'll evacuate against.

curl -X POST https://api.energymap.in/v1/sites/screen \
  -H 'X-API-Key: $KEY' \
  -H 'Content-Type: application/json' \
  -d '{ "lat": 27.54, "lng": 71.91, "capacity_mw": 250, "technology": "solar" }'

GET /v1/connectivity/forecast/{sub_id}

Probabilistic clearance timeline across the next eight quarters.

GET /v1/ists/expansion-plans

CTUIL transmission expansion plan tracker, by region and energisation date.

IES TSP conformance

Every substation and queue_entry field in the response carries an explicit map to the IES Substation TSP path (or marks it as a proposed contribution where IES is silent). The conformance map is the primary artefact for the IES Taskforce conversation and is published alongside the OpenAPI stub in the docs repo.