A comprehensive diagram of a power transmission system typically illustrates the journey of electricity from its source to the consumer. The key components include:

• Generating Station: Where electricity is produced (e.g., thermal, hydro, or wind power plants).

• Step-up Substation: Located near the power plant, this substation uses transformers to increase the voltage to an extremely high level (e.g., 230 kV to 1000 kV) for efficient long-distance transmission.

• Primary transmission lines: These are the long-distance, high-voltage lines that carry the bulk power across vast distances, often supported by large steel towers.

• Step-down Substation: Located closer to populated areas, this substation reduces the transmission voltage to a lower, more manageable level for sub-transmission.

• Sub-transmission and Distribution System: This network carries power at medium voltages to smaller substations and eventually to local distribution transformers, which then reduce the voltage to levels usable by homes and businesses.