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Great Britain · NESO connection register

Where connection capacity comes back, and when

NESO's transmission and Scottish embedded registers, 29 September 2026, refreshed twice weekly. 426.1 GW of storage capacity is contracted across 1,565 projects, but permitted battery capacity remaining for future gated application windows is zero in all nineteen zones and 99.4% of the 83.2 GW gate 2 book went to projects that were already protected. So this tool does not ask where to build. It asks which positions will fail, when, and at which substation the capacity returns. Size is contracted power (MW).
More on the same register

What the fleet earns in the balancing mechanism is on the operating map.

Every project in the register
Every project the register carries
Applicants and who owns them
Applicants, by contracted storage MW
Show all applicants
Ownership, from Companies House
A developer holds each project in its own company, so the raw register lists one house as twenty applicants. These are grouped by who is behind them. Confirmed means a Companies House filing settles it, named means the developer’s own name runs across the companies at one office, and everything else stays ungrouped. How that is established
The three clocks
Every position runs three clocks at once: its stage in the register, its consent, and the contracted connection date NESO has agreed. Consent coverage is the share of an applicant's contracted storage that has planning approved, which is what separates a project pipeline from an option book. Overdue is capacity whose contracted date has already passed. Click a row for the detail.
Where the queue is stacking up
Marker size
Capacity past its connection date
Capacity that has passed the date NESO published for it
Every row is the register’s own published connection date measured against today. Nothing here is scored, weighted or estimated. A date that has passed is the plainest evidence available that a firm position is in trouble, and it is the only kind on this list. Where every number comes from
Firm capacity that is not late yet
This second table is an estimate and not a fact. It reads the consent stage against the years remaining before the contracted date. Nothing in it has failed.
The connection points in detail
The deepest connection point stacks
Contracted storage capacity assigned to each substation the register names. NESO does not publish a thermal rating for a substation, so this is what is contracted at a point and not what the point can carry. Click a row to zoom.
Standalone against co-located
The register names the full plant composition on every row, so standalone and hybrid separate without inference. What it does not separate is the capacity split at a hybrid site: the megawatts are the whole site, not the battery.
Planning, from the renewable energy planning database
Shown as an independent layer rather than joined to the connection register. The two registers name projects differently and a strict match reaches only 10% of register rows, so a join would be mostly guesswork. Turn on the planning layer to see where applications sit against the queue.
Every layer here can be reused commercially with attribution, except three feature types derived from OpenStreetMap which carry share alike. What you may do with each layer
Fourteen sources, each with the date it was last read and its refresh cadence. Where every number comes from
Duration, from the capacity market
Duration is rising
Weighted mean hours by delivery year, weighted by connection capacity. The capacity market de-rating classes state duration explicitly. It is the only published source for it in Great Britain, because the connection register does not record duration at all.
The firm book against transmission charges
Generation TNUoS tariff for the zone each connection point sits in, 2031 forecast. North Scotland is £97.75/kW and Central London is minus £16.51/kW, a spread of £114 a kilowatt. Storage has its own charging arrangements, so read this as the locational signal rather than a bill.
120 GW is queued at connection nodes with no published location
NESO publishes no position for a strategic connection node. Each family is drawn as the region its name refers to, at a hand set centre with a radius that reflects the extent of that region. That is inference about the name alone, and the layer can be switched off. Where anything will be built is a question the register does not answer.
Points with no published coordinate
Method and caveats
Coordinates come from two sources. NESO's own grid supply point and node lookup, matched on the connection site name the register publishes, and OpenStreetMap's substation layer, matched on the same name after normalising voltage and the word substation away. A name is only accepted where the distinctive words in it identify exactly one mapped substation and every candidate for that name sits within six kilometres, so Botley West does not become Botley Wood. That takes the located points from 334 to 508 of 937 and the located projects from 629 to 902 of 1,563. What remains unlocated is listed above. Two gaps sit behind it. The reform created strategic connection nodes, Trent Valley South, Sussex and Romney, South Anglia and East Kent among them, which have no published location; where the node names an existing parent substation, Leeds North for instance, it is drawn there and flagged. Separately, several hundred distribution level points are named in a form that no published gazetteer carries.
What congestion costs to manage
What the system operator pays to manage flows
Thermal constraint cost, daily settlement values summed by constraint group. Most markets publish no cost of congestion at all. NESO does, which is why this is measured rather than inferred.
Cost is published by constraint group, geometry by boundary name, and nothing published joins the two. The map paints the generation tariff instead, which is the price of constraint and does have geometry. Why it is not drawn
The firm book against that
How the reform allocated every zone
Every zone is allocated to its ceiling, and two of them are not
NESO rations connections against the Clean Power 2030 targets, calculating a permitted capacity per technology per zone. Queue formation allocated all of it. The remaining column is NESO's own published figure for what is available in future gated application windows, and for battery it reads zero in all nineteen zones. For comparison, low carbon dispatchable power keeps 7,821 MW, onshore wind 5,101 MW, offshore wind 1,137 MW, solar 417 MW and long duration storage 162 MW.
Two zones donated capacity and may therefore be open, 585 MW between them, and the published table does not say which reading is right. That is the one thing in this tool the data does not settle. The question, in full
How the reform closed the door
These nineteen zones have no published geometry, so this is a table and not a map. Why
Watchlist 0
Filters
Gate
Consent stage
Configuration
Source: NESO open data API, transmission entry capacity register and Scottish embedded register, both dumped 19 August 2026 and refreshed twice weekly; connections reform results databook and existing agreement register, January 2026; thermal constraint costs, three settlement years; GIS boundaries for GB grid supply points, DNO licence areas and the ETYS 2024 transmission system boundaries. Deduplication rule: one row per project identifier, capacity taken as the sum of MW increase, which is new capacity only. Cumulative total capacity is deliberately not used because it equals connected plus increase and so counts existing plant at a brownfield site; using it inflates the pipeline from 426.7 GW to 438.3 GW. Composition is derived from the register's own plant type field, with reactive compensation ignored when classifying because it is a balance of plant item rather than a generator. Delivery risk and the platform groupings are labelled inference; every other figure traces to a published file. The 27 transmission charging zone boundaries are NESO’s own published GIS file, read 11 September 2026, rounded to three decimal places; they were drawn by hand until then. NESO calls that file approximate, so the zone shapes are clipped to the coastline before they are drawn and the colour stops where the land does. None of the 27 zones reaches the Western Isles, Orkney or Shetland, so those islands take no colour and the four connection points on them carry no charge in this dataset. A further five drawn points stand inside a zone on the map while the register names none for them: Mablethorpe, both Waltham Cross substations, Edinbane on Skye and Harestanes West. That is a gap in the register lookup rather than a fact about the zoning, and it is why nine drawn points in total show no charge. The 19 connection queue zones are still names and descriptions read off a picture in the databook, which is why the zonal screen is a table and not a map. Neighbouring land is Natural Earth. Supported by National Energy SO Open Data, used under the NESO Open Data Licence v1.0. Companies House data is used under the Open Government Licence. The transmission network, 14,866 circuit segments at 132 kV and above and 3,365 substations, is © OpenStreetMap contributors and used under the Open Database Licence, which requires attribution and share alike on any derived database. The same OpenStreetMap substation layer is used as a gazetteer to place connection points the system operator’s own lookup does not carry. Balancing mechanism unit registrations are Elexon open data. Unit positions are inferred from the unit name or the four letter substation code and are not published by Elexon.
No warranty. Every source is published data supplied as is by its publisher, and NESO in particular accepts no liability for errors or omissions. Risk bands and platform groupings are inference and are labelled as such. The charging zone boundaries are NESO’s published file; the connection queue zone areas are descriptions, not boundaries. Nothing here is a load flow study, a valuation or advice.

Version 10 · registers read 29 September 2026, balancing mechanism read 20 August 2026 · four questions, six tabs, draggable map column, three clocks dossier, delivery risk model, constraint cost series, other technology at each point, watchlist carried in the address bar, field dictionary, print stylesheet · CSV export follows the current filter on every tab · data is loaded from this site alone and nothing is sent anywhere else.
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