Pathway of Power: Plant

Electricity & Generation

Electricity is the flow of electrons, tiny particles found in all atoms. Atoms of some metals such as copper and aluminum have electrons that are easily pushed and guided into a stream. When a coil of metal wire is turned near a magnet, electricity will flow in the wire (see diagram #1). This same principle is used in power plants to make large amounts of of electricity.

To produce commercial electricity, a fossil fuel is ignited in the furnace section of the boiler. Water, which is piped through the boiler in large tubes, is superheated and converted to steam. The steam turns turbine blades that are connected by a shaft to a generator. The generator, a huge electromagnet surrounded by coils of wire, produces electricity when it rotates. (see diagram #2).

The push, or pressure, forcing electricity from the generator is measured in volts. The flow of electricity is called current and is similar to water flowing in a stream. Electrical current is measured in amperes (amps).

If you multiply amps and volts, you get watts. A watt is a measure of the amount of work electricity can do. Electrical appliances, light bulbs and motors have certain watt requirements depending on the task they are expected to perform. For convenience, we usually use kilowatts (one kilowatt is 1,000 watts) when speaking about electricity.

Kilowatts of electricity generated in a power plant are sold in units called kilowatt-hours (kwh). For example, a 100-watt light bulb left on for ten hours uses one kilowatt-hour of electricity. A typical residential consumer uses about 15,000 kwh during the year.

Electricity is generated at voltages ranging from 13,000 to 24,000 volts. After electricity is made, devices called transformers increase the voltage to hundreds of thousands of volts for transmission – 345 kilovolts(kv) – an economical way of shipping large amounts of electricity from the plant to key locations within the system.

Once the electricity is given enough push (voltage) to go a long distance, it's ready to begin its journey along conductors. Conductors are cables made up of many strands of wire. A continuous system of conductors through which electricity flows is called a circuit.