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gb_ukpn_ltds_heatmap

UK Power Networks LTDS Capacity Heatmap

Published by UK Power Networks · GB · Twice a year

Grantedcommercial_use_with_attributionHealthy

Demand, generation and reverse-power-flow headroom (MVA) at UKPN's 967 primary substations in London, the East and the South East, with firm capacity, RAG status, limiting factor and past-year connection activity, in the Ofgem LTDS Capacity Heatmap format.

What is withheld, and why

Nothing is withheld. Values are served with the attribution the licence asks for: UK Power Networks, Long Term Development Statement (LTDS) Capacity Heatmap, https://ukpowernetworks.opendatasoft.com/explore/dataset/ukpn-capacity-heatmap/. Keep it with any figure you show.

UKPN's attribution formula ends with the date of last update; serve it beside the attribution from freshness.source_effective_at. The UKPN logo may not be used. Written confirmation that keyed/low-volume API use is fine is an open question to UKPN's open-data team (source-governance.md §8).

Licence and rights evidence

Licence
CC BY 4.0 (opens the operator’s site)
Attribution
UK Power Networks, Long Term Development Statement (LTDS) Capacity Heatmap, https://ukpowernetworks.opendatasoft.com/explore/dataset/ukpn-capacity-heatmap/required
Technical access
Yes
Commercial use
Yes
May be cached
Yes
May be redistributed
Yes
Derived data allowed
Yes

Evidence

Methodology

2 version(s)

UKPN LTDS Capacity Heatmap: headroom from the Network Scenario Headroom Report

gb_ukpn_ltds_heatmap_2026 · v2026-05 (LTDS May 2026, v1.0 files)

Demand and generation available capacity per primary substation, derived from UKPN's Network Scenario Headroom Report (DFES 2025, baseline utilisation and network ratings from the November 2025 LTDS, including planned developments and operational flexibility). Firm capacity is LTDS Table 3A/3B; generation firm capacity is available plus existing generation; reverse power flow total is the N-1 reverse capability of the transformers (LTDS Tables 2A/2B, 50% assumed where rated "<100").

Capacity basis
operator calculated
Network state
n minus 1
Binding
No
Additive across assets
No — do not sum these figures
The method accounts for
reserved: not stated · allocated: not stated · pre-reserved: not stated · pending requests: not stated
Comparability class
gb_ukpn_ltds_heatmap
Documentation
Operator’s method (opens the operator’s site)

The operator’s own caveats

  • "You should make your own checks before relying on it." (UKPN portal terms)
  • "Unused capacity may be contractually committed to customers. Those seeking connection should contact our connections gateway" (UKPN, Network Scenario Headroom Report, the source of available capacity)

UKPN past connection activity (LTDS Capacity Heatmap)

gb_ukpn_ltds_heatmap_activity_2026 · v2026-05

Number and total MVA of budget estimates provided, connection offers made (not yet accepted) and connection offers accepted per substation and proposed connection voltage over the past year (1 March 2025 to 1 March 2026). A flow over a period, not capacity available now: offers made and budget estimates are served as `requested`, accepted offers as `contracted`, each under its own variant.

Capacity basis
operator published
Network state
unknown
Binding
No
Additive across assets
No — do not sum these figures
The method accounts for
reserved: not stated · allocated: not stated · pre-reserved: not stated · pending requests: not stated
Comparability class
gb_ukpn_connection_activity
Documentation
Operator’s method (opens the operator’s site)

The operator’s own caveats

  • "It provides useful context for interpreting available capacity" (UKPN dataset description)

How the publication maps to the model

availability types
["available","total","requested","contracted"]
binding
false
directions
["offtake","injection"]
firmness
["firm","unknown"]
geometry precision
exact
includes reserved projects
null
non additive
true
notes
["Every substation in this release is a primary (6.6–66 kV). GSP and BSP are names of the upstream sites, not records of their own; BSP \"Direct\" means fed straight from the GSP.","Available capacity is headroom from UKPN's Network Scenario Headroom Report: unused firm capacity, negative values indicating a deficit (flagged `deficit` in details).","Reverse power flow available capacity is additional headroom where minimum demand is negative. It is its own series (variant reverse_power_flow), never added to generation headroom; it equals the published reverse-power-flow total at 958 of 967 sites (flagged `equals_published_total`).","Firm and reverse-power-flow total capacities are ratings, served as availability `total`.","Past connection activity (budget estimates provided, offers made and not yet accepted, offers accepted; count and MVA; per proposed connection voltage) covers 1 March 2025 to 1 March 2026 per UKPN's heatmap commentary. UKPN leaves an activity figure out rather than writing 0 (no activity figure in the release is 0), and 15 entries give a budget-estimate capacity without its count: a figure that is not in the file has no series, and none is inferred.","RAG status (UKPN writes it upper case) is from utilisation, maximum demand over firm capacity: >= +5% Green, <= -5% Red, between Amber. It travels in details and attributes as published, with a case-normalised `rag_colour`. Limiting factors are Thermal, Voltage or \"Thermal, Voltage\".","Generation firm capacity is negative at 20 sites (EPN 15, SPN 5), where available generation is a deficit larger than the existing generation; kept and flagged `negative`.","source_effective_at is the files' `date`, UKPN's \"validity date of the latest available resource data\" (2025-03-01 for the May 2026 release), not the issue date.","Split busbars share a site: 901 distinct coordinates for 967 records. UKPN's mRIDs are UUIDv5 minted for this dataset, not CIM identifiers, so they key assets but are not offered for cross-source matching."]
spatial scope
substation
technologies
["generic_load","generic_generation"]
units
["MVA","count"]

Query this source

curl "https://api.gridcapacityapi.com/v1/capacity/search?source=gb_ukpn_ltds_heatmap&limit=20" \  -H "Authorization: Bearer gc_live_..."