How the UK electricity grid works

Electricity is the only commodity that must be manufactured at the moment you use it. Great Britain’s grid is the machine that makes that work: a synchronised network where every generator - from Hinkley Point B’s successors to a hillside wind farm in Scotland - spins in lockstep, and where supply has to match demand every second of every day.

The three layers

Generation happens at around 3,400 power stations, from gigawatt nuclear plants to farm-scale solar. Only about 113 of them are large enough to be wired straight into the high-voltage transmission network and metered in real time - the rest connect to the local distribution networks and are what the industry calls embedded generation.

The transmission system - the pylons - moves bulk power across the country at up to 400,000 volts. It is run by the National Energy System Operator (NESO), which forecasts demand, instructs power stations, and keeps the whole machine at 50 hertz.

The fourteen regional distribution networks (DNOs) step that power down and carry it the last miles to homes and businesses. Each has its own patch - you can browse the fleet inside every one, from North Scotland to London.

Balancing, every second

Demand swings from under 20 GW on a mild summer night to nearly 50 GW on a cold winter evening - see what it is right now. NESO balances it with a stack of tools: flexible gas plants that ramp in minutes, pumped storage that can go from zero to full power in seconds, batteries, paying wind farms to reduce output (curtailment), and trading with neighbouring countries over interconnectors.

The market side runs on half-hour settlement periods: generators submit plans, Elexon meters what actually happened, and the Balancing Mechanism prices the difference. The Grid pulse view shows that machinery live.

Where this site’s numbers come from

Everything on Trydan is public open data: the official Carbon Intensity API for the generation mix and carbon, Elexon BMRS for metered output and interconnector flows, NESO for embedded wind estimates and the historic record back to 2009. No API keys, no paid feeds - and where a number has a caveat (a plan rather than a meter reading, an estimate rather than a measurement), the label says so.