About electricity

Most of the electricity we use each day comes from a power station. Large fan-like machines called turbines turn to create electricity. The electricity reaches us by travelling along wires strung from power poles or towers or run underground. This allows us to switch on our lights, heat and cool our homes and use our appliances.

The most common way of producing electricity is by using fossil fuels. There are three main forms of fossil fuels: coal, oil and natural gas. These fuels were formed millions of years ago, long before the dinosaurs. The remains of plants and animals settled to the bottom of lakes and oceans and were covered by sand and mud.

Over millions of years, the earth's pressure and heat turned the layers of earth into a hard rock-like substance called coal, a thick liquid called petroleum, or an invisible substance called natural gas.

To begin the process of converting fossil fuels into electricity these substances need to be taken out of the ground. Coal mines bring the coal up from underground, while massive drills collect the oil and gas. Coal produces around 64% of the world's electricity, with the remainder coming from water, gas, nuclear and green sources. Most developed countries rely heavily on coal for power.

Coal is a non-renewable resource (which means it will eventually run out), but at current usage there is enough coal in Australia to last for another 700 years or more. Despite this, it is important we preserve it and look for more environmentally friendly ways of producing electricity.

Electricity is always there when you flick a switch or plug something in, but electricity has to travel a long way to get to your home. It is fed through cables, which are either hung from poles or run underground. It is initially sent at very high voltages but this decreases as it gets closer to you, making it safe to use.

1. inside the power plant, coal, oil or gas is burned in a big boiler to create steam. If the plant is hydro-electric, water is used.
2. the steam is used to spin a big fan, known as a turbine. The turbine turns a big magnet inside a generator – like an electric motor that works in reverse - to create an electrical current.
3. the electricity is sent through a transformer to make it the right voltage. This gives the electricity enough pressure to travel long distances.
4. big high-voltage transmission lines carry the electricity to your city or suburb.
5. it passes through sub-stations, where the voltage is lowered to make it safe to use in our homes.
6. it travels through smaller power lines to your house.
7. it passes through an electricity meter that measures how much your family uses.
8. the electricity goes to the switchboard in your home, where it is divided into different circuits for each area of your house.
9. the electricity travels through wires inside the walls to outlets and switches all over your house.
10. you can use the electricity to switch on lights, watch TV, listen to music and cook dinner!

The process of creating electricity is the same in most cases. A turbine is used to create the energy. A turbine spins like a fan, converting the energy from water, wind or steam into mechanical power. There are a number of ways to make a turbine spin.

Most of the electricity used in Australia is made from power plants that burn fossil fuels to create steam. The main type of fuel used is coal, because it allows large amounts of electricity to be produced in one place.

Once the fossil fuels are out of the ground, they are transported to the power plants. Many of Australia's power plants are located close to coal mines, so the fuel does not have far to travel.

If oil is being used it usually first arrives in big tanker ships and then is transported to the plant along huge pipelines.

In Australia, coal fired power stations are built adjacent to coalfields and the coal is transported by conveyor belt. Gas is transported by pipelines.

Another popular way to make electricity is with hydro power – created from water stored in huge dams. The energy created by the water released from these dams is transformed into electricity by hydro-electric turbines and generators. The most famous source of hydroelectric power is the Snowy Mountains Hydro-Electric Scheme.

To make hydroelectric power, water from rain or melting snow is collected and stored in a dam. The flow of this water can be controlled with the opening and closing of the gates or pipes. A dam wall can also create a high water level, which creates more force when the water drops towards the turbine. A large pipe carries the water from the dam to the turbine. The force of the water pushes against the blades and turns the turbines. The rotating turbine is connected to a generator, which makes the electricity.

Volts, amps, and watts measure electricity. Volts measure the "pressure" under which electricity flows. Amps measure the flow or amount of electrons that go past a particular point each second. Watts measure the amount of work done by a certain amount of current or flow rate at a certain pressure or voltage.

To understand how volts, amps and watts are related, think of water in a pipe:

• The water in the pipe has a pressure (voltage) and a flow rate (current).
• Turning on the tap is like turning on a switch - it lets the electrical pressure push electrons through an appliance - just like water being pushed through a pipe.
• You would use lots of water - that comes out really hard (like a lot of watts) - to wash off a muddy car. You would use less water that comes out more slowly - (like less watts) - to fill a glass.

Electricity is not free. To get it into your home and schools costs money. Not everyone uses the same amount. Large families might tend to use a lot of electricity. Small families would use less.

To ensure that Ausgrid charges the right amount for its electricity, electrical retailers read the electricity meter in your home or school.