What the Distribution Grid Does

6 min · difficulty 1/10

The power system has three jobs in sequence. Generation makes the power. Transmission moves it long distances at high voltage. Distribution carries it the last stretch to homes and businesses.

The distribution grid starts at the distribution substation. There, a power transformer steps the transmission voltage down to a level the local lines can use. From the substation, feeders branch out along streets. Smaller transformers near each group of customers step the voltage down again, this time to the level that runs lights and motors.

The Last Stretch: Substation to Meter Horizontal chain of five power-system stages from left to right: Generation, Transmission, Distribution substation, Feeder with Service transformer, and Customer Meter. A gold bracket labeled Distribution grid spans from the Distribution substation to the Meter, excluding Generation and Transmission. Gold arrows label Power flow moving left to right through every stage. The Distribution substation holds a large power transformer; the Feeder box holds a smaller Service transformer. Generation and Transmission are rendered in muted gray to signal they are upstream and outside the distribution grid. The Last Stretch: Substation to Meter Distribution grid Generation Transmission Distribution substation Power transformer Steps down to distribution voltage Feeder Service transformer Steps down to utilization voltage M kWh Meter Power flow Left to right, generation through meter Generation + Transmission (upstream, outside distribution grid) Distribution grid conductor Power flow direction (left to right only) Distribution grid bracket (substation to meter, not generation or transmission) Distribution begins at the substation and ends at the customer meter.
The distribution grid is the last segment of a three-stage chain: it starts where transmission voltage steps down at the substation and ends at the customer meter.

When you size equipment or read a procurement spec, you are almost always working somewhere on this last stretch. Knowing where a piece of gear sits between the substation and the meter tells you most of what you need to ask about it.

How a utility builds and protects its distribution grid sets the baseline for every equipment order that follows. The Feeder tracks the infrastructure investment and modernization programs reshaping that baseline, free, every week.

Question 1 of 2

Where does the distribution system begin?

Educational material only. This is not engineering, safety, or procurement advice. Confirm any value against manufacturer documentation and a licensed professional before specifying equipment.