The Australian electricty grid spans over 5,000 kilometers, further than the journey from Sydney to Perth by car. It’s one of the largest interconnected power systems in the world.
What is ‘the grid’?
‘The grid’ is how we refer to the complex transmission and distribution network that carries electricity from power stations across Australia to your home or business. A basic overview of how the grid works is shown in points 1 – 6 below.
Australia’s eastern and southern states have one of the largest interconnected ‘grids’ or power systems in the world, spanning 4,500 kilometres. This grid services Queensland, New South Wales, the Australian Capital Territory, Victoria, South Australia and Tasmania. The wholesale market for electricity supplied via this grid is managed through the National Electricity Market (NEM).
In Western Australia, the Northern Territory and Mount Isa in Queensland the transmission and distribution networks operate separately from the NEM and from each other.
How energy gets to your home
The role of transmission and distribution networks
Power stations generate electricity. the stations themselves are huge, and are usually located near energy sources such as coal mines, natural gas production plants, or hydro-electric plants. Once generated, the electricity needs to be delivered to where most of its end users are located, which tends to be in cities and major towns – this is where the grid comes in. Steps 2 – 6.
The first substation transformer raises the voltage of the electricity so it can be transported efficienly through the transmission networks to smaller distribution networks (commonly knows as the poles and wires system).
Transmission networks move the electricity from the power stations to the distribution networks so it can be passed into your home or business. The electricity is transmitted at high voltages so that large amounts can travel efficiently over long distances.
Lowers the voltage of the electricity ready to deliver for everyday use. When the electricity reaches the distribution networks, it passes through substations, which use transformers to lower the voltage of the electricity ready to deliver for everyday use.
Carry electricity to its final destination, such as your home or business. Powerlines are often visible along the sides of roads, and sometimes they’re underground.
Home and businesses
Electricity is used by most of us everyday. We charge our phones, power or appliances, lighting and heating. Every building that uses electricity has a meter for measuring consumption and a switchboard for dividing the electricity up into circuits for each area of the building.
“The 209km transmission line between Victoria and Tasmania is one of the longest submarine power cables in the world.”
Electricity meters and circuits in your home or business
Every building that uses electricity has a meter for measuring consumption and a switchboard for dividing the electricity up into circuits for each area of the building.
A circuit is a closed path that an electric current flows through to perform a function, such as making a light work or powering a motor. Wires inside the walls carry the electricity from the circuit to outlets and switches throughout the building.
Circuit breakers or fuses protect circuits from overloading. Circuit breakers act like a switch that automatically turns off the circuit when too much electricity flows through it. Fuses do a similar job, but they contain wires that melt in order to break the circuit.