South Australia has the first power system in the world where rooftop solar can, at certain times, exceed the entire state’s electricity demand.
While this is a valuable part of the transformation to a low carbon energy supply, when combined with our other power sources, sudden variations are causing technical and safety issues to our traditional electricity grid.
To improve our system’s stability and security moving forward, South Australia is in the process of transforming to a modern energy system
Where does South Australia's electricity come from?
South Australia generates almost 70% of its electricity from renewable sources.
By 2024, this is projected to reach 80%, with a target of 100% net renewable energy by 2030.
The remainder is generated from non-renewable sources and from interconnection with other states through the National Electricity Market (NEM).
Renewable energy in South Australia is made up of the wind and solar sources below.
A range of additional renewable energy sources are also being investigated or developed, including geothermal, pumped hydro, renewable hydrogen, and bioenergy.
Distributed Energy Resources / Customer Energy Resources
The term ‘Distributed Energy Resources’ (DER) refers to smaller electricity generation sources such as rooftop solar, home batteries and electric vehicles. These sources are spread out (geographically distributed) across various properties (like homes and businesses), rather than being in one central location or farm. While a rooftop solar system might seem small in the grand scheme of things, when combined across the state, rooftop solar is one of South Australia’s largest power generators. At certain times of the year, it is the largest.
In most cases, DER sources first power the facility (the home or business) they’re installed in. If this facility also has a battery storage system, any excess electricity generated would then be stored into the battery. If this battery was full, or if there wasn’t a battery system, the excess electricity would then be fed into the grid.
To take advantage and to reduce costs, homeowners should use key appliances during the day to soak up the electricity their rooftop solar is generating. Washing machines, dishwashers, clothes dryers, or pool pumps for example, should aim to be used between 11am and 3pm. Unless you have a home battery system installed, electricity you use at night will then come from the grid, at a cost.
These farms use turbines to convert wind to electricity, and supply a significant amount of energy to South Australia, as they can operate day and night, in cloudy, rain or sunny conditions. Major wind farms in South Australia are located in Hornsdale, Lake Bonney, Hallett, and Cape Jervis.
Solar photovoltaic (PV) farms
These are large-scale solar facilities that use PV technology to convert sunlight to electricity. Major solar farms in South Australia are located in Port Augusta, Mannum, Tailem Bend, Coonalpyn and Streaky Bay.
Solar thermal farms
These farms are concentrated solar thermal (CST) plants that use mirrors and lenses to concentrate the sun’s energy. In South Australia we have a solar thermal plant in Port Augusta that utilises the captured heat to operate a major commercial horticulture operation.
Big batteries and large scale energy storage
South Australia has a number of ‘big battery’ and large scale energy storage installations. These are used to support the electricity grid in times of both high and low demand. When demand is high and additional electricity is required, these storage facilities can be used to supply stored electricity. Conversely, at times when more electricity is being generated than the grid requires, these storage facilities can soak up some of the excess electricity.
Another emerging technology for large scale energy storage in South Australia is the production of hydrogen from excess renewable energy.
The above facilities provide support measures known as power system security services. For more information, visit our transforming to a modern energy system page.
South Australia is quickly transitioning from the use of fossil fuels toward clean, renewable sources of power. Our last coal station shut down in 2016.
While renewable energy is now the main source of electricity generated in South Australia, natural gas-fired generation also makes up some of the remaining electricity needed to meet demand.
A relatively small amount of the state's electricity can also come from diesel-fired power stations, but these stations are generally minor stations that operate during rare peak demand periods.
Interconnectors allow the import and export of electricity to and from other states, when required. South Australia currently has two interconnections with Victoria, the Heywood and the Murraylink.
The Heywood interconnector, which began operation in 1989, is part of South Australia’s 275 kV alternating current (AC) transmission network and connects with the Victorian transmission network at Heywood. The capacity of the interconnector was upgraded in 2016 to 650 MW.
The 220 MW Murraylink interconnector is a direct current (DC) 150 kV underground system which began operating in 2002. Converter stations are located at each end of the interconnector, with the Victorian end of the interconnector is in Red Cliffs while the South Australian end is near Berri. At 180 km in length, it is one of the world’s longest underground electricity systems.
Project EnergyConnect is an 800 MW interconnector currently under construction which will connect South Australia to New South Wales and provide an additional connection to Victoria. It’s a new 330 kV system between Robertstown in South Australia and Wagga Wagga in New South Wales. It also contains a 220 KV spur from Buronga in NSW to Red Cliffs in Victoria. In total, the transmission line will be approximately 900 km in length.
The electricity grids of six Australian states and territories are linked though these and other interconnectors. Together these grids are regulated by the National Energy Market (NEM).
Off-grid energy systems enable rural and remote households, businesses, communities and towns to become self-sufficient. They are particularly valuable in remote areas where establishing a standalone or mini-grid system may be cheaper than connecting to a large-scale grid.
In South Australia, most off-grid power is provided by diesel generators. However, the high costs of diesel fuel and transportation are making renewable energy options appealing. The South Australian Government supports off-grid renewable energy systems in areas such as Coober Pedy and the Anangu Pitjantjatjara Yankunytjatjara Lands, and at remote mine sites.
Find out more about our off-grid energy sources and projects.
How is electricity transported to my home or business?
South Australia’s electricity system was originally built to send electricity one-way, from power stations to the end user. This system is changing as electricity is now operating two-ways, with end users sending electricity back into the system.
To improve our system’s stability and security moving forward, South Australia is in the process of transforming to a modern energy system.
When electricity leaves large scale generating sources, like conventional power stations and wind/solar energy farms, it enters the high voltage transmission network. Currently the South Australian network operates in the range of 66,000 Volts to 275,000 Volts.
High voltages allow the electricity to efficiently travel large distances to bulk supply substations, where transformers then reduce it to lower voltages for the distribution network.
The transmission network also links South Australia’s power system to other states, using interconnectors to the National Energy Market (NEM).
South Australia’s transmission network is owned and operated by ElectraNet. They manage transmission lines operating at 275,000, 132,000 and 66,000 volts (275kV, 132kV and 66kV).
From transmission substations, electricity is transported at reduced voltages of 33,000 or 11,000 volts to local substations within the distribution network. This electricity is then distributed to localised transformers, which reduce the voltage even further to supply electricity to homes and businesses, typically at 230/400 volts.
South Australia’s distribution network is leased to and managed by SA Power Networks (SAPN)
If you have a solar system, electricity generated from your solar panels will first power your home or business.
If you have a home battery system also, any excess electricity generated would then be stored into the battery. If this battery was full, or if you didn’t have a battery, the excess electricity would then be fed into the distribution network.
For more information, see Distributed Energy Resources above.
The National Electricity Market (NEM)
The NEM interconnects six states and territories across Australia - Queensland, New South Wales, Australian Capital Territory, Victoria, Tasmania, and South Australia.
The NEM includes a wholesale market to coordinate the dispatch of electricity across the interconnected grids, managed by the independent Australian Energy Market Operator (AEMO).
The electricity market works as a “pool”, or spot market, where power supply by generators and demand from retailers is matched instantaneously through a central, coordinated approach.
You can view the electricity currently being shared across the NEM, and the mix of various electricity generation sources being used.
As a customer, what you are finally charged for your electricity is made up of a range of items. Depending on your circumstances (if you own a solar system for example), a combination of the below makes up your final electricity costs:
- Wholesale costs: the cost the retailer incurs when contracting for and purchasing electricity, generally for a period of time, from the National Electricity Market.
- Network supply costs: the costs associated with transmitting and distributing the electricity to you.
- Retail costs: the costs associated with the retailer running their business and includes items like administration fees and managing accounts.
- Green costs: the costs associated with the state-based energy efficiency and solar feed-in schemes, and the Australian Government’s Renewable Energy Target
- Tariff plan charges: The billing plan you have selected with your retailer also contributes to your electricity costs. Customers on a flat rate plan are charged at the same rate for electricity all day. Customers on a time of use plan (ToU) will have a smart meter on their home and can be charged a different rate for their electricity depending on the time of the day in which it is used.
- Feed in tariffs: If you own a solar system, any excess electricity that’s not being used or stored at your property may be exported back into the grid. When this occurs, your retailer will then pay you for the electricity you ‘feed-in’. There are two types of feed-in payments, the Distributer feed-in tariff (DFIT) and the Retailer Feed-in tariff (RFIT).
The DFIT was a tariff system set up prior to October 2011 and has now closed to new customers.
RFIT is available to anyone with an eligible solar system, which your retailer has agreed to purchase your excess electricity as part of their retail contract. Different retailers offer different rates for RFIT, so it is worth shopping around for a retail deal that most suits your needs.
The DMO was introduced in 2019 to help consumers who don’t often shop around for new electricity deals. The DMO sets a maximum price on how much electricity retailers can charge consumers who are on default plans, known as standing offer contracts. These are the base level contracts customers will find themselves on if they haven't actively shopped around or switched to a new plan.
This price cap set by the DMO also acts as a benchmark across the market, known as the reference price. Energy retailers must use this when advertising their offers to customers, so customers can then use the reference price to compare different electricity plans when shopping around for a new offer.
The Australian Energy Regulator (AER) sets and enforces the DMO.
Regulation of the electricity market and industry
The electricity industry across Australia is governed by electrical acts, regulations, and standards.
- The independent Australian Energy Market Commission (AEMC) make and revise the energy rules and regulations, and provide energy advice to Australian governments.
- The independent Australian Energy Market Operator (AEMO) operates the National Electricity Market’s wholesale market and undertakes national transmission planner functions, to ensure Australians have access to affordable, secure, and reliable energy.
- The Australian Energy Regulator (AER) monitors and enforces the compliance of energy market participants, energy service providers and the AEMO with national energy legislation and rules. The AER also determines the network costs that can be fairly passed on to customers, as well as a maximum price on the rate electricity retailers can charge, known as the Default Market Offer (DMO).
- The Essential Services Commission of South Australia (ESCOSA) is responsible for electricity entity licensing, reporting on the performance of licenced entities , and setting the standards for network reliability.
- Electrical safety and technical regulation in South Australia is the responsibility of the Office of the Technical Regulator (OTR).
Real-time graph of Australia’s supply and demand
This bar graph is updated every few minutes, and shows:
- How much electricity is being generated in each state.
- How much electricity is being used by each state.
- Which energy source is being used to generate the electricity.
Hover over the bars for more information.
You can view a legend for the graph and the data in a table on the Renew Economy website.