Headroom & Growth by GSP Area

Overview

This page shows network headroom and demand/generation growth at GSP area level. For an individual-substation view within a chosen licence area, see Headroom by Substation. Connection queue projects aren't included here — see the Generation & Storage Connection Queue page for that.

Network Headroom

The scenario dropdown below always blends each DNO's own published 2025–2030 forecasts with one NESO regional growth pathway from 2031 onwards, giving headroom as a single continuous timeline rather than a choice between the two. Available years differ by pathway: the Holistic Transition blend runs continuously across 2025–2050, but the Electric Engagement and Hydrogen Evolution blends have a gap over 2031–2034, since NESO doesn't publish those two pathways until 2035.

How to read the map: pick a scenario, a metric, and a year, and the colour of each GSP area shows that metric's value. For Headroom %, colour follows a red/amber/green scale: red means the area's demand already exceeds its firm capacity (a constraint), amber means headroom is positive but under 20%, and green means headroom is above 20%. Hover over an area to see its exact figures, including how many of its individual substations fall into each of those three tiers.

Demand & Generation Growth

Growth figures come entirely from NESO's regional energy scenario pathways. The DNOs' own LTDS forecasts don't publish these figures at all, so this section offers a choice of pathway only, with no LTDS blend. The year slider adjusts its range to match: Holistic Transition spans 2031–2050, while Electric Engagement and Hydrogen Evolution start at 2035.

How to read the map: the Demand Growth Index is not an absolute figure — it's each GSP area's demand relative to that pathway's own base year (2025 for Holistic Transition; 2035 for Electric Engagement and Hydrogen Evolution), where 1.0 means no change from the base year and 1.5 means 50% higher demand. Use Total Demand (GWh) instead if you want the absolute figure behind that index.

Data sources

• Network headroom (firm capacity vs. forecast demand), 2025–2030: each DNO's published Long Term Development Statement (LTDS) — the network planning report every distribution licensee issues annually, giving substation ratings and demand forecasts directly for these years.
• Longer-term demand and generation growth, 2031–2050, is not a separate NESO substation forecast — it's each substation's own 2030 LTDS figure grown forward by a regional multiplier. NESO's regional energy scenario pathways (tRESP) publish growth rates at GSP area level, not at substation level, so every substation within the same GSP area is scaled by the same regional growth factor regardless of that substation's own individual trajectory. Two substations with very different 2030 headroom can therefore show the same proportional change from 2031 onwards if they sit in the same GSP area.
• Demand figures are shown in MVA. For DNOs that publish MW (UKPN, NGED, SSEN SHEPD), we convert using a single power factor recorded for 2024/25, applied unchanged across every forecast year to 2050. As electrification shifts the load mix over that horizon, the real power factor will move away from this fixed one — understating or overstating capacity utilisation for those DNOs. It's the only power factor NESO or the DNOs currently publish, so there isn't yet a better one to use.
• GSP area and licence area attribution: each substation's location comes from each DNO's own published location dataset — supply-area boundary polygons, asset registers, or coordinate exports — matched by substation name to its LTDS ratings and forecasts. Licence area is taken from the LTDS source the substation was published in. GSP area is resolved in two steps instead: first by testing which GSP area boundary physically contains that location; and, where a substation has no usable coordinates, by falling back to a name-based lookup between each DNO's own GSP group naming and NESO's GSP area identifiers. A handful of substations have no confirmed mapping under either method — out-of-area classifications, and cases where a DNO's GSP group straddles a NESO licence-area boundary — and are pending review by a domain expert with access to NESO's own boundary data. Those substations carry no GSP area here.
• Licence areas are shown individually rather than rolled up by DNO, because some DNOs (e.g. SSEN's SEPD and SHEPD) cover spatially distinct, non-contiguous areas.
• GSP area totals exclude any substation with no confirmed GSP area mapping (see above) — its capacity and demand are left out of every GSP area's total here, rather than being forced into the nearest one.
• Headroom % is capacity-weighted, not a simple average. Each GSP area's headroom percentage is its total headroom divided by its total firm capacity — a large substation with tight headroom moves the area figure more than a small one would, which is the right basis for a planning decision but means it can differ from a plain average across the area's substations.
• Green/amber/red substation counts shown on hover use fixed thresholds against each individual substation's own headroom: green above 20%, amber between 0% and 20%, red below 0% (demand already exceeding firm capacity).