Electricity
Use this route when you need to understand where assets sit, how voltage falls through the system, who owns which layer, and why a connection that looks simple on paper can still end up in a long queue.
Click any stage to explore it. Electricity flows from generation through balancing and networks to consumers, with governance shaping every stage.
10.3 GW operational interconnector capacity
Generators convert primary energy into electricity and feed it onto the grid through either transmission or distribution connections, depending on project scale and system impact. Interconnectors also move electricity across GB's cross-border links. Licence and connection requirements vary by asset type, threshold, and where the project connects, so route-level descriptions should stay specific rather than universal.
Independent public corporation from 1 October 2024
The National Energy System Operator keeps supply and demand matched every second. If frequency drifts from 50 Hz, NESO instructs generators or storage to ramp up or down through the Balancing Mechanism and procures ancillary services such as response, reserve, and reactive power. Balancing costs remain sensitive to constraint management, forecast error, and late operational actions.
RIIO price controls set allowed revenue
Transmission carries bulk power at 275 kV and 400 kV, plus 132 kV in Scotland, across Great Britain. Three transmission owners maintain the transmission assets. Distribution networks then step voltage down through 14 licensed areas to deliver electricity to homes and businesses. Ofgem regulates these monopoly networks through RIIO price controls and licence obligations.
40.01 million smart meters installed
Around 30 million households and several million business premises draw power from the grid. The default tariff cap, supplier obligations, and market switching rules govern the retail experience. Smart metering is changing how consumption data flows through the settlement chain and eventually into MHHS.
CfD, Capacity Market, RIIO, default tariff cap
Ofgem sets licence conditions and price controls. DESNZ sets energy policy, clean power targets, and oversees levy control. Industry codes (Grid Code, BSC, CUSC, DCUSA, REC) provide the contractual and operational framework. The governance layer does not generate or consume power, but it shapes every commercial and operational decision across the system.
Follow electricity from the national backbone to the final consumer supply. The hierarchy is still the clearest mental model for understanding where capacity, ownership, and visibility change.
This is the backbone. Large generators, offshore wind, and interconnectors land here first. Three transmission owners keep those high-voltage corridors moving power from generation-heavy regions into major demand centres.
This is the bridge between the national backbone and local networks. In England and Wales, 132 kV is classed as distribution. In Scotland, it can still count as transmission. This is where constraints start to become visible to project developers.
Primary substations feed towns, business parks, storage sites, and medium-scale industrial loads. Feeder loading, transformer ratings, and voltage control matter far more here than political headlines about headline generation capacity.
This is the last step down to homes and businesses. It is also where EV charging, rooftop solar, and heat pumps create the most visible local stress. Visibility is still patchy at this level, which is why data quality matters so much.
Large strategic assets sit with the transmission owners. Most project developers, local authorities, and building owners hit the distribution layer first, so it matters to distinguish transmission owners, incumbent DNO licence areas, and the wider IDNO market.
National Grid Electricity Transmission
Carries power from central generation across England and Wales to Grid Supply Points where DNOs take over.
SP Transmission (ScottishPower)
Connects the Scottish lowland wind corridor and industrial demand in the central belt.
SSEN Transmission (SSE)
Operates the longest geography and handles the route from Highland and island generation back into the mainland grid.
Great Britain's incumbent distribution network is still arranged as 14 licence areas, but current Ofgem materials group those areas under six incumbent owners. Most local connection questions run into one of these operators first.
National Grid Electricity Distribution
East Midlands, West Midlands, South West, and South Wales. The largest DNO group by geographic spread in England and a major flexibility-market test bed.
UK Power Networks
London, South Eastern, and Eastern Power Networks. Dense demand, heavy distributed generation, and expensive underground reinforcement make this one of the hardest areas to expand quickly.
Northern Powergrid
Northern and Yorkshire distribution areas. A mix of industrial loads, rural overhead networks, and offshore wind connection activity along the east coast.
SP Electricity North West
North West England remains a single incumbent licence area. Current Ofgem consultations refer to the owner as SP Electricity North West, while the licensed entity remains Electricity North West Limited within the ScottishPower group.
SP Energy Networks
SP Distribution and SP Manweb. High wind penetration and cross-border operating context create a distinctive planning environment.
SSEN Distribution
Covers islanded and remote networks in Scotland plus dense southern England routes. The engineering mix ranges from subsea cable issues to rapid heat-pump and EV growth.
A constraint is the gap between the flow the market wants and the flow the physical network can carry. That is why the queue question is really a network question.
Much of the GB network was designed around large centralised power stations. New wind, solar, storage, and flexible demand are more geographically distributed and often land in places that do not yet have strong routes back to the main corridors. When the intended flow exceeds thermal rating, voltage margin, or fault level capability, the project runs into a constraint.
NESO can pay some generators to turn down and others to turn up so power can route around physical bottlenecks.
Substations, transformers, reconductoring, and planning consents usually make network reinforcement a long delivery task rather than a quick administrative fix.
A Grid Supply Point transformer is already operating at 95% of thermal rating. A new solar farm wants to connect downstream at 33 kV. The DNO cannot offer firm access without either curtailment conditions or a second transformer. That reinforcement can take five to ten years, which is why a site that looks viable on paper can still sit in the queue for a long time.
Site choice, headroom, offer terms, and energisation belong in one chain. Breaking them apart usually hides where the real delay enters.
Choose the substation and voltage level that fits the project.
Week 1The first choice is physical, not political. Pick the wrong substation or voltage level and you can spend months modelling a path that was never likely to work.
NESO or the DNO models whether spare capacity really exists.
Weeks 2 to 6If spare capacity exists, the route is straightforward. If not, the operator identifies reinforcement, curtailment conditions, and delivery risk. This is usually where project timelines widen materially.
Submit power factor, protection, fault contribution, and design assumptions.
6 weeks to 6 monthsThe formal application turns narrative interest into engineering scrutiny. Offer terms depend on real electrical characteristics, not just the headline megawatt figure on a development slide.
Deliver private works, shared reinforcement, and final commissioning checks.
1 to 15 yearsThis stage covers construction, metering, protection tests, compliance, and energisation. The queue exists because this delivery chain is long, physical, and hard to compress once upstream reinforcement is needed.
Last reviewed: 17 March 2026
The route keeps the live React map as the working source of truth, but the surrounding structure is now tied more explicitly to current Ofgem licence and ownership material. Operator cards distinguish transmission owners from the 14 incumbent distribution licence areas and from the six current owner organisations that operate those areas, avoiding the misleading shorthand claim that Great Britain simply has "six DNOs".
Next route
Continue into voltage management, transformer ratings, and the local planning rules that shape reinforcement spend.