Kōkiri Learn

Background reading · Science

Where our power comes from, and how to stay safe

Most of Aotearoa's electricity comes from moving water, heat from the ground and wind. The same power that runs your home can hurt you, so respect it.

Flick a switch and a light comes on instantly. But that electricity may have started its journey hundreds of kilometres away, in a lake in Fiordland or a steaming valley near Taupō.

Making electricity

Electricity is generated by turning other kinds of energy into electrical energy. In most power stations, something spins a turbine, and the turbine turns a generator full of magnets and coils of wire.

  • Hydro: water falling from a lake or dam spins the turbines, as at Manapōuri and Clyde.
  • Geothermal: steam from hot rock deep underground spins them, in places like the central North Island.
  • Wind: moving air spins giant blades, as at Te Āpiti in the Manawatū.
  • Solar: panels turn sunlight straight into electricity with no moving parts.

    • In most years, well over three-quarters of New Zealand's electricity comes from these renewable sources, mostly hydro. Using less electricity, especially on cold winter evenings when demand peaks, means less needs to come from burning gas or coal.

    Mains power is different

    The batteries in your class circuits give a few volts. The sockets at home give about 230 volts, enough to stop a heart. Keep these rules:

  • Never poke anything into a socket or open an appliance.
  • Keep water away from anything plugged in, and never touch switches with wet hands.
  • Look up for power lines before flying kites or climbing trees, and stay well away from any fallen line.
  • If a plug, cord or appliance is damaged, hot or smells like burning, tell an adult straight away.

    • Small changes add up

    Turning off lights in empty rooms, switching screens off at the wall and using LED bulbs all cut power use. An energy audit helps you find which changes save the most.

    Sources and further reading

    Written for Kōkiri Learn students in our own words. Check facts against the sources.

    Used in: Spark: Static and Circuits