Skip to Main Content
The electric distribution system in the United States is celebrating over 125 years of design, development, expansion, and evolution. During that time, thousands of utilities that sprung up across the country met their customer's needs with many different types of system configurations, frequencies, and line voltages. Today, these systems serve nearly 138 million customers that use 3.66 trillion kWh. This article provides a brief synopsis of the prevalent distribution systems in use today. Of necessity, it must omit discussion of many of the types of systems that remain from those historical beginnings. In no way is this meant to diminish the importance, efficacy, or adequacy of those systems that currently satisfy customers' needs that are not described herein.