Power for the 21st century

As the 20th century progressed, the human population increased dramatically. Rapid advances in science, and our ever increasing knowledge and understanding of the nature of energy and matter, saw the development of an array of labour saving devices and new technologies. The mass supply of electricity was a key ingredient in allowing this technological progress. We are all used to flicking the electrical switch and having a reliable source of energy available instantly.

Explore an interactive resource that shows how electricity is generated and is transferred from the power station to the consumer. Use the resource on the interactive learning guide “energy supply to homes.”

The method for generating and supplying large amounts of electricity generally involves the following components to produce an electric circuit;



An Energy Source to supply the energy to operate a turbine or generator (e.g. coal, gas, hydro, wind, solar, thermal, biomass and nuclear in some countries that can be transformed into electrical energy. Find out more about Energy sources.



A Generator - uses energy from the source, often to spin a turbine first, which then rotates coils of conductors in the generator to produce the changing magnetic fields required to produce electrical energy. Find out more about Generators.


Transformers - the transformer changes the voltage of the electrical energy. Very high voltages are used to transmit the electrical energy over long distances efficiently and then another transformer close to where the electricity will be converted to other energy forms by consumers, lowers the voltage to a safer value for use by consumers. Find out more about transformers


Transmission lines - conducting wires to carry the electrical energy. They attach the different components together in an electric circuit. Transmission lines are made from highly conductive aluminium with a stainless steel core to make them strong. 


A Load - this is where the electrical energy is to be used, e.g. the television, the refrigerator, the lights in the city or a house.


This process is very similar to the electric circuits you studied in Years 7 and 8 Science, i.e. the circuits you studied had a source of energy (battery or power pack), transmission wires (the metal conducting wires you used to attach the circuit components together), the Load (the light globe or Resistor you used in the circuit).

The power pack you use in class at school to power electrical circuits or devices in science is really a transformer that converts the 240 volt supply from the power point to lower voltages for you to do experiments (2 to 12 volts).

The power packs you use to charge electronic devices such as game consoles and mobile phones are also transformers.

Electrical cord