How Energy Infrastructure Gets Planned

Current Planning Data Position

For the first time the planning artefacts share a settled, published cadence rather than drifting on separate clocks. Three changes did it. Ofgem approved the Centralised Strategic Network Plan methodology in April 2026, so the rules for computing the national network-investment plan are fixed; a transitional plan follows in June 2026 and the first full plan by the end of 2028.⁸⁷ The Strategic Spatial Energy Plan, the statutory plan for where new capacity should sit, has a confirmed timetable: methodology approved in 2025, first iteration in late 2026, consultation in early 2027 and a final plan in autumn 2027.⁶ And the Future Energy Scenarios moved from a yearly rebuild to a multi-year cadence with a costs annex in between, so the national pathway work no longer churns every twelve months while the spatial and network plans do the year-on-year work.⁴

The significance is practical. A developer, a network company or an analyst can now read each artefact at a known date and trust that the others will arrive on a matching schedule. Before April 2026 the network methodology was still in consultation and the spatial timetable was a working assumption; with both fixed, the stack reads as one synchronised production line.

The stack from national scenarios to a connection offer

The planning data divides into six layers, each feeding the one below it. Read top to bottom, it runs from the broadest national view down to a single project getting connected.

1. 1
   National scenarios: the Future Energy Scenarios (FES)

   NESO's set of plausible futures: how much wind, solar, storage, hydrogen, heat and transport demand the whole system might have, year by year, to 2050. It is the envelope every other plan reads.

   Lead: NESO
2. 2
   Regional plans: RESP and the transitional tRESP

   What the national picture means for each of eleven regions. Each local network area also breaks FES down substation by substation as its Distribution Future Energy Scenarios (DFES).

   Lead: NESO, with the distribution network operators
3. 3
   Spatial plan: the Strategic Spatial Energy Plan (SSEP)

   Where new generation, storage, hydrogen production and carbon capture should be located. A statutory plan under the Energy Act 2023; a material consideration for planning decisions, though not a consent itself.

   Lead: NESO with DESNZ
4. 4
   Network plan: the Centralised Strategic Network Plan (CSNP)

   What wires, substations and reinforcements have to be built to connect what the spatial plan places. It sets the investment Ofgem funds through the price controls.

   Lead: NESO with Ofgem
5. 5
   Asset model: the Long Term Development Statement (LTDS)

   The validated, machine-readable record of the network that actually exists, against which every plan is checked. Now published as a common data model rather than spreadsheets.

   Lead: the distribution network operators, under Ofgem direction
6. 6
   Connections: a firm place on the grid

   Individual projects apply and are assessed against the layers above through the Gate 2 process, which progressed 283 GW of generation and storage and 99 GW of demand in April 2026.

   Lead: NESO and the network operators; see the connections page

National scenarios: FES, and how areas turn it into DFES

The Future Energy Scenarios are NESO's long-running set of plausible system futures, describing demand, generation, storage, hydrogen, heat and transport out to 2050. They are not a single forecast: each scenario is an internally consistent world built on different assumptions about how fast consumers adopt new technology, how quickly policy moves and how costs fall. Read together, the scenarios give the range of futures that the rest of the stack has to be able to handle. A single scenario carries the demand projection by sector and region, the generation mix by technology, the flexibility and storage stack, the hydrogen system, and the carbon trajectory; a costs annex carries the price and capital-cost trajectories that feed every scenario. The Electricity Ten Year Statement is the transmission-network companion that works out what each scenario implies for the high-voltage network.⁴⁵

National scenarios are too coarse for a local decision, so each distribution network operator runs a Distribution Future Energy Scenarios cycle that breaks the national pathways down by primary substation and by year. The DFES feeds the operator's network development plan and its capacity heatmap, which in turn shape connection offers and reinforcement decisions. Where the local data is good, applications can be routed faster; where it is thin, the operator assumes the cautious case and connection-cost estimates rise. The DFES, the per-operator Embedded Capacity Register of connected and contracted plant, and the LTDS together are the local data that the regional and spatial plans read upward, all published under Ofgem's presumed-open Data Best Practice expectation.¹⁶

Regional plans: RESP and the transitional tRESP

Between the national scenarios and the local network sits a regional layer. NESO's Regional Energy Strategic Planning divides Great Britain into eleven regions, one for Scotland, one for Wales and nine for England, and produces a plan for each. The geography follows administrative boundaries rather than network licence areas, which adds a reconciliation step but lets the plans engage local authorities and combined authorities in the geography they already work in. A transitional version, the tRESP, has been published as a first baseline while the full method is finalised, with the full regional plans following.¹³

Each region carries a distinct energy character that the plans read into the work: major onshore and offshore wind and the Scotland-to-England boundary constraint in Scotland; Celtic Sea floating wind and the South Wales industrial cluster in Wales; offshore wind and the Humber and HyNet carbon-capture and hydrogen clusters across the north; high urban demand and heat networks in London and the West Midlands. The regional layer is where the national envelope becomes a regional allocation that the spatial plan can then place precisely.⁶

Where it goes (SSEP) and what gets built (CSNP)

The Strategic Spatial Energy Plan answers where. NESO prepares it with DESNZ under the Part 5 strategic-planning functions of the Energy Act 2023 (the Independent System Operator and Planning provisions), which is a stronger legal footing than any earlier GB planning artefact: the plan is laid before Parliament and is a material consideration that planning authorities must weigh. The first iteration covers electricity generation, electricity storage, hydrogen production and carbon-capture infrastructure across Great Britain, mapping where each should sit by reconciling the national scenarios against network capacity, demand, land use and environmental constraints. The methodology was approved in 2025, the first iteration is due in late 2026, consultation runs in early 2027 and the final plan lands in autumn 2027.⁶ What it is not is a planning consent or a connection offer: it locates good regions, but each project still needs its own consent and still applies to connect.⁹

The Centralised Strategic Network Plan answers what to build. It is the network-investment counterpart to the spatial plan: NESO computes, with Ofgem, the reinforcements needed to connect what the spatial plan places, across transmission and distribution together, and sets the investment envelope that Ofgem funds through the price controls. Ofgem approved the methodology in April 2026; a transitional plan follows in June 2026 using the existing scenarios, and the first full plan is due by the end of 2028, reading the final spatial plan as an input.⁸ Ofgem has directed that the first full plan be submitted by September 2028 and published by December 2028.¹⁰ The shift here is that one integrated plan now covers both transmission and distribution, so an offshore wind farm in the North Sea and the distribution reinforcement that absorbs its export can be planned in one document, on one methodology, with one funding envelope.⁷

The data substrate that carries the stack

The six layers only work as a stack if their data can move between them. Three pieces make that possible. The Energy Digitalisation Framework, published jointly by DESNZ and Ofgem in March 2026, sets a shared five-layer model that any energy data programme must align to, from the user-facing applications at the top to the physical assets at the bottom.¹⁴ The Data Sharing Infrastructure is the shared exchange that the framework asks NESO to build, so a planner can discover and receive the scenarios, the spatial plan, the network plan and the asset models through one accredited route instead of many separate data deals; it is treated in full on the digital infrastructure page.¹² NESO's Sector Digitalisation Plan sets out how the sector delivers against the framework.¹⁵

The piece that makes publication an obligation rather than a favour is the GC0139 Grid Code change. It would require the network companies to publish the planning data that the spatial and network plans consume, in the common data model, at the cadence those plans need, so NESO can ingest it without negotiating with each company every cycle.³ The framework supplies the model, the infrastructure supplies the exchange, and GC0139 supplies the duty to publish. Together they turn the planning stack from a set of separately published documents into a connected production line.

Worked example: a 49 MVA battery through the stack

A developer planning a 49 megavolt-ampere battery in the East Midlands reads the stack in order, and each layer narrows the decision.

Reading each artefact at its published date, rather than only when the connection is needed, makes the case stronger at each step: the spatial iteration confirms the regional signal, the network plan confirms the reinforcement, the LTDS Stage 3 publication later in 2026 adds the planning and connection data to the Stage 2 model, and the full network plan in 2028 integrates the final spatial plan. The cadence is now settled, even as the content of each artefact keeps evolving.