In Australia, when a state’s power grid becomes overwhelmed there is an eleventh-hour practice that’s employed in an effort to keep the lights on. This process is known as load shedding.
If a state needs to implement load shedding it’s a surefire sign that the system is struggling to cope. When there isn’t enough power supply to match electricity demand the grid can become unstable, potentially damaging essential infrastructure and leaving customers without power for lengthy periods. Load shedding eases imbalances in the National Electricity Market (NEM).
All of Australia’s states and territories, aside from Western Australia and the Northern Territory, are connected to the NEM. This wholesale market allows generators and retailers to trade electricity, delivering around 80% of the country’s entire electricity consumption.
How does load shedding work?
Load shedding is the controlled reduction of electricity supply to parts of the power system servicing homes and businesses, according to the Australian Energy Market Operator (AEMO).
Although it’s a rare occurrence it can take place at any time as a result of various factors. For example, prolonged storms and heatwaves or sustained infrastructure outages. Load shedding is a completely different action to both planned and unplanned local outages.
AEMO will only resort to load shedding after exhausting all other options, including importing more power from other states and tapping into emergency energy reserves. If all other measures fail load shedding will be authorised as a last-ditch effort to prevent a major collapse.
However, AEMO doesn’t decide which particular areas are shed. They figure out how much electricity consumption needs to be reduced and distribution companies and government determine how this will be carried out on a local level. Approaches vary from state to state and, where possible, load shedding is executed on a rotational basis.
The primary concern is to minimise the impact on crucial community services, particularly major health facilities and hospitals, emergency services and public transport systems.
What might trigger load shedding in Australia?
Fossil fuel sources - such as coal, oil and natural gas - made up almost three quarters (71%) of the country’s total electricity generation in 2021, according to the latest Australian energy statistics.
Although this figure is down 5% year-on-year, natural resources remain the dominant form of electricity generation compared with renewable sources - such as solar, wind and hydro - which comprise less than a third (29%) of the nation’s total energy generation.
This means that we’re heavily reliant on coal-fired power stations. When these facilities experience malfunctions and incidents that cause shut-downs it can have a huge impact on the NEM.
Australia's east coast endured a power squeeze from mid-May to mid-June when around one quarter of the market's coal-fired capacity had been offline for maintenance or unplanned outages. Further pressures were applied as a result of disruptions in the coal supply chain and skyrocketing global coal and gas prices.
The immediate crisis was averted after the AEMO stepped in and suspended the NEM, seizing control of the nation’s power supply and pricing. Shortly thereafter, around one third of the coal-fired plants that had been offline returned to service.
"Challenges remain in the energy sector and AEMO will continue to monitor supply levels and risks across all regions," the national market operator said.
Over the past decade, there has been no major load shedding event in Australia, according to Ausgrid. In February 2011, power was switched off on a rotating basis to about 1,000 customers over one hour intervals during the evening peak periods in parts of Enfield in Sydney’s Inner West. This transpired after cable faults limited supply from the local Enfield Zone Substation at a time when demand for power hit record levels for consecutive days during extreme hot weather.
Although prime minister Anthony Albanese would not rule out the possibility of load shedding occurring in the future, energy minister Chris Bowen told a press conference last month, “We are confident we can avoid blackouts. We will work hard to avoid load shedding.”
What can you do?
In areas where load shedding is applied the power supply is switched off and customers will experience blackouts. There is often very little warning so it pays to always be prepared.
It’s handy to have torches, candles and backup generators on hand. If you have a gas barbecue, make sure that the gas bottle is full so you’ll be able to boil water and cook hot food. If shedding occurs at night leave a light turned on so you'll know when power has been restored.
As a preventative measure to avoid load shedding you can switch off non-essential household appliances such as dishwashers, washing machines, driers and pool pumps, or at least delay using them until after 8pm when electricity demands subside. Rather than pumping the air conditioner all summer, use a pedestal fan to cool your home.
Ensuring that your home is not solely reliant on fossil fuel resources as a means of electricity is also helpful. Consider renewable energy sources, such as solar power, as an alternative.
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