The electricity that’s powering your computer is being produced and transmitted to your machine as you read this. Electricity cannot be made and stored for future use — and that’s why planning for energy needs is a complex undertaking. Here’s a brief overview of how electricity is produced and delivered.

Illustration reprinted with permission from the Edison Electric Institute

1. Electricity is generated by the power plant. 2. Electricity leaves the power plant and travels to a “step-up” substation, where its voltage is increased to make long-distance transmission more efficient. 3. Next, the energy travels along a transmission line to the area where power is needed, such as a town or city. 4. Once electricity reaches the town or city, voltage is decreased, or “stepped-down,” at another substation to voltages that can be used by homes and businesses. 5. A distribution power line carries the electricity to a home or business.

The Grid

The U.S. electric system is made up of three major components:

• Generating plants that produce electricity, such as the Canal Generating Station;
• Transmission lines (high-capacity cables) that carry electricity at high voltages from generating plants to load centers (e.g., communities); and
• Distribution facilities that lower the voltage and send the current to homes and businesses via power lines.

Roughly 12 percent of the electrical lines you see along the highway are high-voltage transmission lines; the rest are distribution lines. An interlocking system of transmission lines is called a grid.