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gb_enwl_heatmap_tool

ENWL Heatmap Tool

Published by SP Electricity North West · GB · When the operator updates it

Archived, pending reviewpending_reviewHealthy

Firm and N-0 demand headroom, N-0 generation headroom by generator type and battery headroom (MW) at every ENWL primary substation and BSP, with the Appendix G transmission position of each GSP.

What is withheld, and why

Every value from this source is withheld. The operator’s terms do not clearly allow us to redistribute its figures, and when signals conflict the more restrictive reading wins until the operator confirms otherwise in writing. Records are still listed — with capacity.value null, access.status "withheld" and a link to the publication — so you know the operator publishes something there.

The publication is still read and kept, because operators overwrite their files and a history not recorded when it happened can never be recovered. If reuse is cleared, customers get the history as well as the present.

The workbook sits under the enwl.co.uk website terms, which require a licence for commercial use, and the embedded user guide reserves all rights. The same figures are on ENWL's Opendatasoft portal behind a login (gb_enwl_heatmaps) with a CC BY 4.0 licence field, but that portal's terms link leads to the same website terms; per source-governance §4 the more restrictive reading governs both until ENWL confirms otherwise in writing (dataportal@enwl.co.uk). Fetched and kept, never served.

Licence and rights evidence

Licence
Not stated
Attribution
SP Electricity North West, Heatmap Toolrequired
Technical access
Yes
Commercial use
No
May be cached
Not established
May be redistributed
No
Derived data allowed
Not established

Evidence

Methodology

2 version(s)

ENWL Heatmap Tool — primary and BSP headroom

gb_enwl_heatmap_tool_2026 · v2026-08

Spare capacity estimated by a high-level assessment of thermal loading of circuits and transformers, fault level and voltage step change, per connection type; primary figures take account of constraints at the associated BSP.

Capacity basis
operator calculated
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_enwl_heatmap
Documentation
Operator’s method (opens the operator’s site)

The operator’s own caveats

  • Please note that the data presented in this tool is based on high level analysis and as such may differ from the results of a formal connection application.
  • The values of spare capacity quoted by the Heatmap Tool are based on total capacity available to connections not the maximum size of an individual connection
  • These include 132 kV network constraints and the effect of meshed networks

ENWL Heatmap Tool — Appendix G summary

gb_enwl_heatmap_tool_appendix_g_2026 · v2026-08

The Appendix G return per converted GSP: connected and contracted power stations in Parts 1–4, the materiality headroom NESO determines at the transmission interface (Part 5), capacity in project progression, and the aggregated developer capacity limit.

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_enwl_appendix_g
Documentation
Operator’s method (opens the operator’s site)

The operator’s own caveats

  • Note that the capacities reported in the table above were true prior to the ongoing Connections Reform, hence only indicative.

How the publication maps to the model

availability types
["available","connected","contracted","requested","total","unknown"]
binding
false
directions
["offtake","injection","bidirectional"]
firmness
["firm","conditional","unknown"]
geometry precision
exact
includes reserved projects
null
non additive
true
notes
["Firmness from ENWL's user guide: Demand Firm is \"secure for the loss of a single circuit\"; every other figure is \"based on a N-0 connection i.e. a connection that is constrained off for the loss of the first circuit\" and is conditional.","Inverter-based generation \"includes photo-voltaic sites and many types of wind generator\": generic_generation with variant inverter_based; synchronous LV and HV are variants too. Battery storage (MIC = MEC) is one bidirectional value.","Primary and BSP locations are British National Grid easting/northing (EPSG:27700), as published.","Appendix G (sheet 7) is a separate methodology. Parts 2 and 3 (\"connected or contracted to connect\") have no single availability type and are unknown; Part 1 connected, Part 4 contracted, Part 5 materiality headroom available, project progression requested, the aggregated developer capacity limit total.","Transmission fault-level headroom is in kA, which the unit vocabulary does not carry; it is kept as an attribute, with \"TBC\" as written.","Sheet 6 (GSP Demand Headroom) is hidden in the workbook and pairs Firm/Non Firm with non-inverter/inverter labels the guide does not define; it is not read. Unlabelled columns (E, Q, R, S on sheet 4) are kept in the provenance record by their column letter and mapped to nothing.","No substation codes are published in the workbook; primary, BSP and GSP names are the identities."]
spatial scope
substation
technologies
["generic_load","generic_generation","battery"]
units
["MW"]

Query this source

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