National Electricity Market

Most electricity in Australia is generated, bought, sold and transported in markets that need to match supply and demand in real time. The National Electricity Market (NEM) fills this role for the east coast and southern states.

What is the NEM?

The NEM is one of the largest interconnected electricity systems in the world. It covers around 40,000 km of transmission lines and cables, supplying around 9 million customers.

The NEM is a wholesale market through which generators and retailers trade electricity in Australia. It interconnects the six eastern and southern states and territories and delivers around 80% of all electricity consumption in Australia.

Western Australia and the Northern Territory are not connected to the NEM. They have their own electricity systems and separate regulatory arrangements.

How does the NEM work?

The NEM facilitates the exchange of electricity between generators and retailers. Retailers resell the electricity to businesses and households. High voltage transmission lines transport the electricity from the generators to electricity distributors, who deliver it to homes and businesses on lower voltage ‘poles and wires’.

The wholesale market is where generators sell electricity and retailers buy it to on-sell to you. There are lots of generators and retailers participating, so it’s highly competitive. The wholesale market operates around a common pool, or spot market, for wholesale trading in physical electricity. This process determines an electricity spot price which reflects physical supply and demand across the NEM. This spot price is an important price signal for investors.

Financial markets sit alongside the wholesale market and involve retailers and generators entering into contracts to buy and sell electricity at an agreed price. The financial markets enable retailers to manage the risk of volatile wholesale prices for their customers. 

Who manages the NEM?

The COAG Energy Council is the key decision maker with policy and governance responsibility. The Australian Energy Market Commission (AEMC) develops the rules by which the market must operate. The Australian Energy Market Operator (AEMO) handles the day-to-day operations of the electricity and gas markets. The Australian Energy Regulator (AER) enforces the rules and makes judgements on the regulatory proposals of monopoly network operators.

The Energy Security Board (ESB) has been established by the COAG Energy Council to coordinate the implementation of the reform blueprint produced by Australia's Chief Scientist. Part of the role is to report to the Energy Council on the health of the NEM. The health report will track the performance of the system, the risks it faces, opportunities for improvement and affordability issues.

Is the NEM changing?

The NEM needs to be modernised to accommodate and respond to changes in electricity generation, emerging technologies, such as batteries, and shifting consumer preferences. The government’s long-term energy policies are being informed by recommendations of the Australian Competition and Consumer Commission (ACCC) in its Retail Electricity Pricing Inquiry Report, and recommendations in the Independent Review into the Future Security of the NEM, which provides a blueprint for ensuring Australia’s energy systems remain affordable, reliable, sustainable and secure while transitioning to low emission forms of generation.  

The ACCC Retail Electricity Pricing Inquiry

On 27 March 2017, the Treasurer issued a notice requiring the ACCC to hold a public inquiry into the supply of retail electricity and the competitiveness of retail electricity prices in the NEM. The inquiry formally commenced on this date.

The Final Report, released on 11 July 2018, sought to identify the root causes of high electricity prices across the entire electricity supply chain, and made 56 recommendations aimed at improving electricity affordability for Australian consumers and businesses.

The government continues to work with State and Territory colleagues through the COAG Energy Council in progressing many of these recommendations, and has already taken action to drive down prices through implementation of the ACCC recommended default offer price safety net.

The government has also tasked the ACCC to continue to monitor prices, profits and margins in the supply of electricity in the NEM. As part of this ongoing inquiry, the ACCC is required to report to the government at least every 6 months until the conclusion of the inquiry on 31 August 2025.

More information

About the COAG Energy Council

About the Australian Energy Market Commission (AEMC) Australian Government

About the Australian Energy Market Operator—video (AEMO) Australian Government

Introduction to the NEM factsheet (PDF 893KB) (AEMO) Australian Government

National Electricity Market overview (AEMO) Australian Government

State of the energy market reports (AER) Australian Government

About the Australian Energy Regulator (AER) Australian Government

Final Report - Independent Review into the Future Security of the National Electricity Market 

Final Report - Retail Electricity Pricing Inquiry (ACCC) Australian Government

Ongoing Electricity Market Monitoring (ACCC) Australian Government

Energy supply

Energy basics for business

Energy basics for households 

Consumer rights (AER) Australian Government