Electricity enhances your life, from lights and entertainment to your home’s comfort level. But electricity must travel long distances to reach your doorstep. The process needed to deliver power from Point A (power plant) to Point B (your home) combines several key components, including substations.
Energy can’t be stored, so moving electricity requires packing power as heavily as possible onto transmission lines. By increasing electricity’s voltage—a force that acts like water pressure—it moves more efficiently.
Highways of energy
Substations serve as essential “transit” points in this system. They raise, or “step up,” and lower, or “step down,” voltage. While high voltage may be great for speeding power along transmission highways, if electricity enters your home at too high a level, electronics could be damaged.
As power gets closer to its destination, substations decrease it to a safe level. Substations also keep voltages constant, preventing harmful fluctuations.
Several types of substations are found between power plants and homes. Initially, step-up substations at power plants increase voltage to various levels (between 115,000 volts and 765,000 volts) so it can be shipped through high-voltage transmission lines.
Lowering the voltage
Once electricity gets closer to its destination, transmission substations typically reduce voltage to between 23,000 and 69,000 volts.
From there, power moves over smaller transmission facilities to electric co-op distribution systems, where more substations slash voltage even lower, normally to 12,500 volts.
At this point, the distribution lines you see running along rural roads bring power to you. To make it safe for household use, a transformer, usually mounted on a utility pole near your house, cuts the voltage once more, to between 120 and 240 volts.