Electricity and 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 turns near a magnet, electricity flows in the wire (see diagram 1). This same principle occurs in power plants and power stations to make large amounts of electricity.
Most of the power plants and power stations in the TXU system are known as fossil fuel plants. Fossil fuels -- lignite or coal, natural gas and oil -- come from the decayed plant and animal life buried in the earth millions of years ago.
To produce commercial electricity, a fossil fuel is ignited in the furnace section of a boiler. Water, which flows through the boiler in large tubes, gets superheated and converted to steam. The steam turns turbine blades connected by a shaft to a generator. The generator, a huge electromagnet surrounded by coils of wire, then 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 what we call a current and it is similar to water flowing in a stream. We measure electrical current 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 perform. Because power plants and power stations produce -- and appliances use -- large amounts of watts, we often speak in kilowatts (one kilowatt is 1,000 watts) to avoid very large numbers when talking about electricity.
Customers purchase kilowatts of electricity generated in a power plant in units of kilowatt-hours. For example, a 100-watt light bulb left on for 10 hours uses one kilowatt-hour of electricity.
Electricity is generated at voltages ranging from 11,000 to 24,000 volts. After electricity occurs, devices called transformers increase the voltage to hundreds of thousands of volts for transmission. This is an economical way to ship large amounts of electricity from the power station to key locations in an electricity retailer's system.
Once the electricity receives 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. Now, follow the path of power to the transmission lines.