What is Transmission?
Transmission lines and transmission substations carry power at high voltage from where it is generated to substations. There it is transformed to lower voltage so it can flow across subtransmission and distribution lines to substations and, ultimately, across the lines that supply local customers. Transmission lines use larger poles, or structures, and longer wire spans between poles than local distribution lines. Transmission voltages are those above 100 kV. The Vermont transmission voltages include 345 kV, 230 kV and 115 kV lines.
The parts of Vermont’s electric grid: power supply, transmission, subtransmission & distribution
Diagram shows a very simplified picture of the grid without showing how it is interconnected, or networked, nor the role of smart metering and other technological innovation.