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How Electricity Reaches You

Trace the journey of electricity from generation through transmission and distribution to the end consumer, so learners have a concrete mental model before any architecture discussion begins.

PreliminaryDerived from TOGAF

Voltage tiers from generation to your wall socket

Five voltage tiers form a step-down ladder from 400/275 kV transmission at the top to the 230 V customer outlet at the bottom. A downward axis tracks the falling voltage and a red bracket marks the DNO licence boundary over the lower tiers.

Every voltage step is a handover between operators with different licence obligations. The grid supply point is the formal interface where NESO releases bulk transmission into the local distribution network the DNO is licensed to run.

Voltage tiers from generation to your wall socket A vertical step-down ladder of five voltage tiers with a left-hand axis pointing down, labelled voltage steps down. A left gutter shows the falling voltage band beside each panel, and each panel names the stage and its operator. From the top: Transmission at 400/275 kV run by NESO; Grid supply point at 132 kV, the formal handover from transmission to local distribution, shared and marked in amber; Primary distribution at 33 kV; Secondary distribution at 11 kV; Customer outlet at 230 V. A red bracket on the right and a red note below state that the DNO licence boundary starts at the grid supply point, so everything from 132 kV down to 230 V is licensed to the distribution network operator. Voltage steps down 400/275 kVTransmissionBulk power from generation across the country on overhead linesNESO 132 kVGrid supply pointThe formal handover from transmission to local distributionNESO / DNO 33 kVPrimary distributionBulk feeders out to primary substations that step voltage downDNO 11 kVSecondary distributionLocal feeders along streets to the substation by each estateDNO 230 VCustomer outletService cable into the meter cabinet at the customer premisesDNO / Customer DNO licence boundary Transmission (NESO)Grid supply point handoverDistribution (DNO) The DNO licence boundary starts at the grid supply point.Everything from 132 kV down to 230 V at the wall socket is licensed to the distribution network operator.