Electricity 101

Electricity is the flow of small particles known as electrons, which are found in atoms, the smallest part of an element that cannot be broken down by chemical means. Electrons in the atoms of metal such as copper and aluminum are easily moved together along a wire by revolving a metal coil, or turbine, near a magnet. The push of electrons by the turbine/magnet setup is measured in units called volts. The flow of electrons along wire makes an electric current, which is measured in amperes or Amps.

The production of electricity is called generation, and is measured in kilowatts (one kilowatt is equal to 1,000 watts). The electricity produced by a generation or power plant facility is sold in units called kilowatt-hours. Generation facilities are the first step in providing electricity to customers.

High-voltage electricity produced by generation facilities is moved through transmission lines. Tranmission lines move electricity long distances to substations. Large transformers at substations reduce, or step down, the high-voltage electricity so it can be moved along the distribution system.

The distribution lines are the everyday poles and wires you see on the streets or connected to your house. These wires deliver the electricity to the customers, either in the form of a three-phase (or three-wire) line or a single-phase (or one-wire) line. Three-phase lines are typically used by large commercial customers who run heavy machinery, while single-phase power serves the needs of smaller residential customers.

In either case, electricity is then stepped down again to reach the customers' home or businesses by a smaller distribution transformer, which can usually be seen on a utility pole outside your house. In some cases, these smaller transformers are mounted on the ground, and are called pad transformers. Electricity then passes through your meter and into your home's network of electrical wires and outlets.