Published by Australian Academy of Science
Australia’s low emission energy future Box 3 | Electricity generation

Most electricity today is generated using heat. In a coal-fired power station, for example, coal is burnt to heat water, which turns to steam, which is used to spin turbines.

© Oncor Corp. 2001

The shaft of a turbine is attached to a device for producing electricity called a generator; it consists of large magnets attached to the shaft inside a coil of copper wire. The rotating turbine turns the generator shaft and its attached magnets; as they rotate the magnets cause a flow of electrons – an electrical current – in the wire coil by a process known as electromagnetic induction. Electrical current can also be produced if, instead of moving the magnets in the coil, the coil is rotated inside large magnets. The coil is connected at both ends to an electrical circuit; the electrical current flows from the generator coil through the electricity grid to light and heat our houses, work our appliances and run factories.

Power plants that use uranium, natural gas or oil operate in a similar way to coal-fired power stations. These systems all rely on the use of steam or another gas to turn the blades of a turbine. (Wind and hydroelectricity also work by turning turbines.)

Related sites

• Coal fired power station (Queensland Resources Council, Australia)

• How electricity is made (CS Energy, Australia)

• So how does an electricity generator work? (ActewAGL, Australia)

• How generators work (Wisconsin Valley Improvement Company, USA)

Other boxes

Box 1. Reducing emissions by increasing energy efficiency