ATC

How transmission works

Electricity is delivered to homes, schools, hospitals, businesses and industries through an integrated system of generating plants, power lines and substations. Transmission lines, which consist of heavy cables strung between tall towers, carry power from where it is generated to areas where it is needed. The transmission network allows the movement of large amounts of power over long distances.

How power is delivered to your home:

Electricity is generated by utilities and other energy producers at various types of power plants, wind and solar farms. Electricity is “stepped up” or transformed to higher voltages at substations before it enters the network of high-voltage transmission lines. Electricity from the transmission network is reduced to lower voltages at substations, and electric distribution companies then bring the power to homes and businesses.

Interconnections ensure reliability

Because electricity cannot be stored, it must be generated, transmitted and distributed at the moment it is needed. The high-voltage transmission grid is the vital link between power plants that generate electricity and the people who need it.

In the early days of electrification, power plants were small and generated electricity for immediate areas. As demand for electricity increased, utilities built larger, more efficient power plants and developed transmission systems to carry the energy over longer distances to larger numbers of customers over wider areas.

To increase efficiency and reliability, regional transmission systems were connected to allow power to flow from one region to another, which also lowered costs by providing more paths over which the bulk electricity supply could flow. Today’s electric transmission “grid” reflects this regional approach to bulk electricity transportation.