How the Electric Grid Fits Together

Where this fits

Generation, high-voltage transmission, substations, distribution, loads and controls viewed as one connected system.

Core system ideas

Generating resources inject electrical power into a network that moves it across transmission and distribution systems.

Substations transform voltage levels, switch circuits, measure conditions and connect different parts of the network.

Control centres, protection systems, communications and field crews keep the physical network coordinated and recover service after disturbances.

Interfaces and tradeoffs

The most useful way to understand this topic is to place it in the chain from energy conversion to customer service. Definitions, units and system boundaries should be explicit before comparing technologies.

What organizations measure

Demand, generation, frequency, voltage, flows, outages and restoration status.