GENERATION: After the power plant generates the electricity, it is sent through a transformer. Transformers are critical to electrical transmission because they can change the voltage of the electrical current, making it more efficient, economical and practical to transmit. Prior to transmission through power lines, the transformer “steps up” the voltage, which means the generated voltage is changed to a higher voltage. This way, lower currents can transmit the same energy, thus reducing resistive loss.

TRANSMISSION: The transmission system consists of large, high-voltage power lines. The lines are ever-present around the country, often near roadways. Sometimes, they travel underground or under the sea. This system can carry electricity over long distances, sometimes greater than 400 miles. In North America, there are three major transmission systems: The Western Interconnect, The Eastern Interconnect and the Electric Reliability Council of Texas.

DISTRIBUTION: The local distribution system consists of substations and smaller, lower-voltage distribution lines. The transformer at the substation “steps down” the voltage to a lower voltage. Then, the system distributes the electricity from substations and transformers to households. One final transformer steps down the voltage to 120V which is what people use in their homes.