Top 10 biggest energy companies in Australia

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The largest energy companies in Australia are AGL, EnergyAustralia and Origin Energy; aka the Big 3.
Origin Energy has Australia’s largest market share.
ActewAGL, Aurora Energy, Ergon Energy, Momentum Energy, Red Energy and Lumo Energy are all government-owned companies.

In this guide, we’ll break down what you need to know about the big energy companies in Australia, plus list other information that may help you find a deal best suited to your household’s power needs.

You’ve probably heard about the ‘big four’ banks when it comes to finance, but what about the ‘big three’ in energy? We’re referring to Origin Energy, AGL and EnergyAustralia, which currently have the largest retail market share across the deregulated states.

There are numerous reasons why Australians are more likely to trust a household name – such as a wide selection of products or longer call centre hours. But just how many Australians choose the big energy companies? Find out with Canstar Blue below.

What are the largest energy companies in Australia?
What is a tier 1 energy retailer?
What are tier 2 energy retailers?
Biggest electricity companies in Australia by market share
What are the biggest gas retailers in Australia?
Which electricity retailers are government-owned?
What about small business energy?
Does a bigger energy company mean better energy deals?

What are the largest energy companies in Australia?

Origin Energy, AGL and EnergyAustralia are the biggest energy companies in Australia. Known as the ‘big three’, each has a significant share in the residential electricity and gas markets of New South Wales and South Australia. While they also hold a huge combined chunk of the Victorian and South East Queensland market, their dominance has been notably reduced in recent years.

The total market share of the big three energy providers in each state can be found below.

State	Big three market share
NSW	73.7%
VIC	55.79%
QLD	49.1%
SA	73%

Source: Australian Energy Regulator (AER) Retail Energy Market Performance Update for Quarter 2, 2024-25. Essential Services Commission (ESC), Victorian Energy Market Report 2022-23.

AGL

Founded back in 1837, AGL Energy is Australia’s oldest energy company and services around 4.3 million accounts – both residential and business. AGL retails electricity and gas in NSW, VIC, SEQ and SA, as well as gas only in WA. AGL tends to market three products in each state, including solar offers, all with variable rates.

AGL electricity prices

Here are the AGL Energy plans on our database for NSW. These are products from a referral partner†. These costs are based on the Ausgrid network in Sydney but prices may vary depending on your circumstances. This comparison assumes general energy usage of 3,900kWh/year for a residential customer on a single rate tariff. Please use our comparison tool for a specific comparison in your area. Our database may not cover all deals in your area. As always, check all details of any plan directly with the retailer before making a purchase decision.

Here are the AGL Energy plans on our database for Victoria. These are products from a referral partner†. These costs are based on the Citipower network in Melbourne but prices may vary depending on your circumstances. This comparison assumes general energy usage of 4,000kWh/year for a residential customer on a single rate tariff. Please use our comparison tool for a specific comparison in your area. Our database may not cover all deals in your area. As always, check all details of any plan directly with the retailer before making a purchase decision.

Here are the AGL Energy plans on our database for SE QLD. These are products from a referral partner†. These costs are based on the Energex energy network in Brisbane but prices may vary depending on your circumstances. This comparison assumes general energy usage of 4,600kWh/year for a residential customer on a single rate tariff. Please use our comparison tool for a specific comparison in your area. Our database may not cover all deals in your area. As always, check all details of any plan directly with the retailer before making a purchase decision.

Here are the AGL Energy plans on our database for South Australia. These are products from a referral partner†. These costs are based on the SA Power network in Adelaide but prices may vary depending on your circumstances. This comparison assumes general energy usage of 4,000kWh/year for a residential customer on a single rate tariff. Please use our comparison tool for a specific comparison in your area. Our database may not cover all deals in your area. As always, check all details of any plan directly with the retailer before making a purchase decision.

EnergyAustralia

EnergyAustralia has a portfolio of roughly 2.4 million customers throughout Australia, and has proven to be a serious contender to Origin Energy and AGL over the years. The energy retailer operates in NSW, VIC, SEQ, SA and the ACT. EnergyAustralia currently offers variable rate plans and one fixed rate plan, including solar offers in those states.

EnergyAustralia electricity prices

Here are the EnergyAustralia plans on our database for NSW. These are products from referral partners†. These costs are based on the Ausgrid network in Sydney but prices may vary depending on your circumstances. This comparison assumes general energy usage of 3900kWh/year for a residential customer on a single rate tariff. Please use our comparison tool for a specific comparison in your area. Our database may not cover all deals in your area. As always, check all details of any plan directly with the retailer before making a purchase decision.

Here are the EnergyAustralia plans on our database for Victoria. These are products from referral partners†. These costs are based on the Citipower network in Melbourne but prices may vary depending on your circumstances. This comparison assumes general energy usage of 4000kWh/year for a residential customer on a single rate tariff. Please use our comparison tool for a specific comparison in your area. Our database may not cover all deals in your area. As always, check all details of any plan directly with the retailer before making a purchase decision.

Here are the EnergyAustralia plans on our database for SE QLD. These are products from referral partners†. These costs are based on the Energex network in Brisbane but prices may vary depending on your circumstances. This comparison assumes general energy usage of 4600kWh/year for a residential customer on a single rate tariff. Please use our comparison tool for a specific comparison in your area. Our database may not cover all deals in your area. As always, check all details of any plan directly with the retailer before making a purchase decision.

Here are the EnergyAustralia plans on our database for South Australia. These are products from referral partners†. These costs are based on the SA Power network in Adelaide but prices may vary depending on your circumstances. This comparison assumes general energy usage of 4000kWh/year for a residential customer on a single rate tariff. Please use our comparison tool for a specific comparison in your area. Our database may not cover all deals in your area. As always, check all details of any plan directly with the retailer before making a purchase decision.

">Origin Energy

Origin Energy retails electricity and gas to over 4.7 million customers, making it Australia’s largest energy retailer. Origin sells electricity in New South Wales, Victoria, South East Queensland, South Australia and the Australian Capital Territory, as well as natural gas in these states plus Western Australia. The energy giant usually has a few market offers to choose from, all of which vary according to customers’ needs.

Origin electricity prices

Origin Energy Prices NSW

Here are the Origin Energy plans on our database for NSW. These are products from a referral partner†. These costs are based on the Ausgrid network in Sydney but prices may vary depending on your circumstances. This comparison assumes general energy usage of 3900kWh/year for a residential customer on a single rate tariff. Please use our comparison tool for a specific comparison in your area. Our database may not cover all deals in your area. As always, check all details of any plan directly with the retailer before making a purchase decision.

Origin Energy Prices VIC

Here are the Origin Energy plans on our database for Victoria. These are products from a referral partner†. These costs are based on the Citipower network in Melbourne but prices may vary depending on your circumstances. This comparison assumes general energy usage of 4000kWh/year for a residential customer on a single rate tariff. Please use our comparison tool for a specific comparison in your area. Our database may not cover all deals in your area. As always, check all details of any plan directly with the retailer before making a purchase decision.

Origin Energy Prices QLD

Here are the Origin Energy plans on our database for SE QLD. These are products from a referral partner†. These costs are based on the Energex network in Brisbane but prices may vary depending on your circumstances. This comparison assumes general energy usage of 4600kWh/year for a residential customer on a single rate tariff. Please use our comparison tool for a specific comparison in your area. Our database may not cover all deals in your area. As always, check all details of any plan directly with the retailer before making a purchase decision.

Origin Energy Prices SA

Here are the Origin Energy plans on our database for South Australia. These are products from a referral partner†. These costs are based on the SA Power network in Adelaide but prices may vary depending on your circumstances. This comparison assumes general energy usage of 4000kWh/year for a residential customer on a single rate tariff. Please use our comparison tool for a specific comparison in your area. Our database may not cover all deals in your area. As always, check all details of any plan directly with the retailer before making a purchase decision.

What is a tier 1 energy retailer?

A Tier 1 retailer is an energy provider that has more than 10% of the market share in a network region (i.e. Ausgrid or Essential Energy), which include the big three. Tier 1 retailers also include the likes of Alinta Energy, Engie (formerly known as Simply Energy) and the dual ownership of Red Energy and Lumo Energy in some network areas.

What are tier 2 energy retailers?

According to the AEMC, a Tier 2 retailer is an energy provider that holds less than 10% of the market share in a network region. A decade ago, Tier 2 retailers were almost non-existent in most states. However, there are more than 15 of these smaller companies operating today, helping increase the level of competition across Australia.

Cheap electricity deals

Compare the prices of the top energy companies in your state:

Here are some of the cheapest published deals from the retailers on our database that include a link to the retailer’s website for further details. These are products from referral partners†. These costs are based on the Ausgrid network in Sydney but prices may vary depending on your circumstances. This comparison assumes general energy usage of 3900kWh/year for a residential customer on a single rate tariff. Please use our comparison tool for a specific comparison in your area. Our database may not cover all deals in your area. As always, check all details of any plan directly with the retailer before making a purchase decision.

Here are some of the cheapest published deals from the retailers on our database that include a link to the retailer’s website for further details. These are products from referral partners†. These costs are based on the Citipower network in Melbourne but prices may vary depending on your circumstances. This comparison assumes general energy usage of 4000kWh/year for a residential customer on a single rate tariff. Please use our comparison tool for a specific comparison in your area. Our database may not cover all deals in your area. As always, check all details of any plan directly with the retailer before making a purchase decision.

Here are some of the cheapest published deals from the retailers on our database that include a link to the retailer’s website for further details. These are products from referral partners†. These costs are based on the Energex network in Brisbane but prices may vary depending on your circumstances. This comparison assumes general energy usage of 4600kWh/year for a residential customer on a single rate tariff. Please use our comparison tool for a specific comparison in your area. Our database may not cover all deals in your area. As always, check all details of any plan directly with the retailer before making a purchase decision.

Here are some of the cheapest published deals from the retailers on our database that include a link to the retailer’s website for further details. These are products from referral partners†. These costs are based on the SA Power network in Adelaide but prices may vary depending on your circumstances. This comparison assumes general energy usage of 4000kWh/year for a residential customer on a single rate tariff. Please use our comparison tool for a specific comparison in your area. Our database may not cover all deals in your area. As always, check all details of any plan directly with the retailer before making a purchase decision.

Here is a list of other electricity retailers and their residential market share in Australia:

ActewAGL: 2.6%
AGL: 21.7%
Alinta Energy: 4.7%
Aurora Energy: 3.5%
Dodo: 1.1%
EnergyAustralia: 13.6%
Energy Locals: 0.9%
Engie (formerly Simply Energy): 2.0%
Ergon Energy: 9.3%
Origin Energy: 26.2%
Powershop: 0.9%
Red Energy: 7.5%

The above figures have been sourced from the Australian Energy Regulator (AER) Retail Energy Market Performance Update, 2024-25.

What are the biggest gas retailers in Australia?

According to the Australian Energy Regulator (AER), AGL, Origin Energy and EnergyAustralia represent almost 77.1% of the residential gas market. AGL maintains the largest market share at 34.6%, Origin Energy with 25.6% and EnergyAustralia at 16.9%. Following behind the big 3 gas suppliers is ActewAGL (4.8%), Red Energy (6.5%) and Alinta Energy (3.4%).

Which energy retailers are government-owned?

The following energy companies in Australia are owned by the government:

ActewAGL: Operating in the ACT and regional parts of New South Wales, ActewAGL is jointly owned by Icon Water Limited (an ACT government owned corporation) and AGL via subsidiary companies
Aurora Energy: A government-owned electricity and gas retailer operating in Tasmania
Ergon Energy: Regional Queensland customers in cities like Cairns, Mackay, Rockhampton and Townsville will likely be connected to the government-owned electricity distributor and retailer, Ergon Energy
Momentum Energy: Owned and operated by Hydro Tasmania – a Tasmanian government business enterprise and generator – Momentum Energy retails electricity to homes and businesses in New South Wales, Victoria, South East Queensland and South Australia
Red Energy and Lumo Energy: Red Energy and Lumo Energy are both retail subsidiaries of Snowy Hydro – a federal government-owned energy generation company

What about small business energy?

The retail market share within small business energy is dominated by the big 3, who service nearly 58.2% of customers across the National Electricity Market (NEM). For gas, it’s a similar situation, with Origin claiming over half of the market share (55.2%), AGL holding 20.7% and EnergyAustralia coming in with 12.1%.

Does a bigger energy company mean better energy deals?

Finding a great deal on energy is certainly achievable with the big three power companies, although being larger in size doesn’t automatically mean the ‘best’ or cheapest deals. It may come down to browsing a range of energy deals from multiple energy retailers, particularly as the industry continues to evolve and new offers enter the market. To see how the biggest energy providers compare in your area, click the link below.

Original reporting by Jared Mullane
Image Source: arturnichiporenko/Shutterstock

Katrina Hasdell

Energy Content Producer

Katrina Hasdell is an Energy Content Producer at Canstar Blue, where she covers Australia’s retail energy market. Katrina is dedicated to providing consumers with easy-to-read information on their energy options so they can get better deals on electricity, solar power and more.