Managing electricity supply requires coordination across a range of different electricity governing bodies, product and service suppliers.

At its highest level, that includes those who support the operation of the National Electricity Market (NEM) such as energy ministers, policy and market rule makers, and those who support the day-to-day operation of the electricity market.

How is electricity made?

The point at which electricity is made is known as generation. Electricity can be generated from renewable and non-renewable sources. Different energy sources include coal, hydroelectricity, solar panels (including solar farms and rooftop solar), wind turbines and gas-powered generation.

How does electricity get to you?

Once electricity has been generated, supply is fed through electricity assets and equipment from those who generate energy (known as generators), through to those who convert energy into voltages fit for delivery to customer supply points. This includes transmission and distribution businesses; and involves coordination between the different electricity governing bodies, product and service suppliers.

How is electricity transported?

Electricity is transported from generation sources using transmission and distribution powerlines and infrastructure. You will often hear these referred to as “poles and wires”; however, there are many different types of assets that carry and store energy. These also vary in size, shape and function depending on if they are transmission or distribution assets.

To move electricity safely requires keeping the energy at specific frequencies and managing voltage changes as the energy moves through this electricity infrastructure. As an electricity distributor, Essential Energy’s distribution network delivers electricity at voltages to enable safe use by end-use customers.

Distribution transformers transform the distribution voltage to the service level voltage directly used in households and industrial plants.

How is supply managed?

We work with the Australian Energy Market Operator (AEMO) and Transgrid to actively manage the network to ensure stable and reliable power supply.

The AEMO is responsible for operating the National Electricity Market (NEM), which includes our network. Transgrid is responsible for operating and managing the main high voltage transmission network in New South Wales, to which our distribution network connects.

What happens if there are electricity supply constraints?

AEMO must keep the power system operating securely and reliably; that means keeping supply and demand in balance all of the time, and keeping the power system operating within its technical limits.

When electricity supply is constrained or there is an incident and this means that the power system will not operate securely, AEMO issues directions to power generators, transmission network operators like Transgrid and distribution network operators including Essential Energy.

This can include directions to proactively manage access to off-peak power when demand is high. Off-peak power is usually available when demand is lower mid-morning, mid-afternoon and overnight. Customers use it for hot water systems and irrigation pumps.

In extreme conditions, to help keep the overall network operating securely, access to off-peak power may be temporarily removed. Access is restored when demand returns to lower levels.

In circumstances where there is a lack of supply in the power system, lack of reserve actions can be implemented by the AEMO. As a last resort, these may result in unplanned power outages for short periods of time for Essential Energy customers. They are designed to maintain a safe, secure and reliable power system by preventing longer lasting outages from impacting large parts of the network.

What is load shedding?

Load shedding is a controlled process where the electricity supply is temporarily turned off in certain areas to maintain the broader security of the electricity network.

Load shedding may occur during times of peak demand, or when the amount of electricity being generated is reduced.

The role of load shedding is to ensure that key infrastructure services such as emergency services, sewerage systems and telecommunications networks can remain connected.

Other times when load shedding may occur include unexpected power failures or maintenance, transmission events such as damage to powerlines or other infrastructure, and extreme weather events such as storms, bushfires or floods that can damage the power grid and reduce supply.

Load shedding is a last resort measure to protect the power grid and ensure electricity can be restored as quickly as possible. Understanding its causes and impacts can help in finding solutions to minimise its occurrence. 

How does load shedding occur?

AEMO is responsible for issuing load shedding directions to transmission operators such as Transgrid and distribution network operators including Essential Energy.

Load shedding occurs under the NSW Jurisdictional Load Shedding Guidelines.

When load shedding is expected to last more than two hours, identified areas are rotated to share the load being shed and the inconvenience of a power outage - this helps to reduce the impact on individual customers under the guidelines.

Load rotation is generally completed between one and two hours, with a maximum outage time of four hours, where practical, for any individual customer.

Why is hot water impacted when managing the electricity supply?

Many people use electric hot water services to heat their water.

When there are electricity supply constraints, some customers who have an off-peak water heating system may have this turned off.

When this occurs, hot water services are restored once Essential Energy receives a direction that it is safe to do so.

In extreme conditions, to help keep the overall network operating securely, access to off-peak power may be temporarily removed. Access is restored when demand returns to lower levels.

How to mitigate load shedding

By reducing the demand on the electricity network, you can help reduce the need for load shedding.

Use energy-efficient appliances and practices, especially when there is a higher electricity demand.

Consider investing in renewable energy sources like solar and batteries to store the energy you capture.

Adopt energy-efficient habits, such as unplugging devices when not in use or turning the lights off when you leave a room.

Further information

• Read more about heatwaves and power supply.
• Find out more about energy efficiency for your home.
• Information about AEMO can be obtained from their website.