A substation is a crucial component of the electrical power grid, serving as a connection point between the transmission network, electricity generators, large load customers, and the lower voltage distribution network. Substations are strategically located around the region to move high-voltage power over long distances to where it’s needed most.
Contrary to what some may think, substations do not generate power. Instead, they transform the voltage of the electricity produced by the generator, increasing it from an average of between 12,000 and 22,000 Volts, up to transmission voltages of 132,000 and 275,000 Volts. This high voltage electricity is then transported over long distances via transmission lines. Upon reaching its destination, the voltage is transformed back down to 66,000, 33,000 or 11,000 Volts to enter the distribution network, making it safe for use in homes and businesses.
Substations house a variety of equipment, the largest being transformers. They also include small buildings for staff facilities and technology for protection and control systems. This technology allows the site to be remotely monitored and operated from a central control room.
Some substations, known as switchyards, do not house transformers. These switchyards are remotely operated to re-route power supplies where there is an immediate or critical need.