Quick Answer:
The “Big 3” energy retailers in Australia are Origin Energy, AGL, and EnergyAustralia. Together, they account for over 65% of the electricity retail market in the National Electricity Market (NEM), which services most states except WA and the NT. These three providers have shaped the Australian energy landscape for decades—but that doesn’t mean they’re always the cheapest or most flexible option for everyone.
Why are these companies called the ‘Big 3’?
It’s a term that sticks because of market share, infrastructure control, and customer reach. These three energy giants have long dominated electricity and gas retailing across Australia’s east and south.
They own or control parts of the energy generation and retail supply chain, giving them a stronghold in both production and delivery.
Here’s a breakdown:
| Company | Approximate Market Share (Residential, NEM) | Notable Features |
|---|---|---|
| Origin Energy | ~27% | Owns generation assets (gas, solar, hydro) + extensive retail |
| AGL | ~23% | One of the oldest and largest integrated energy firms |
| EnergyAustralia | ~15% | Backed by China Light & Power, services 1.6 million+ customers |
Source: AER State of the Energy Market Report (2024)
What does each Big 3 retailer actually do?
1. Origin Energy
- Founded in 2000, based in Sydney
- Offers electricity, gas, solar systems, and broadband
- Owns generation assets like the Eraring Power Station (Australia’s largest coal-fired plant, scheduled to close by 2025)
- Has expanded into cleaner energy, including large-scale solar farms and hydrogen projects
Interesting fact:
Origin has partnered with Tesla to roll out virtual power plants—essentially turning home batteries into a collective energy resource.
2. AGL Energy
- Established in 1837 (yes, the 1800s!)
- Offers electricity, gas, solar, and energy storage
- Owns significant coal, gas, and renewable generation assets
- Recently split into AGL Australia (retail and small-scale renewables) and Accel Energy (big power stations)
Social proof in action:
AGL has over 4 million customer accounts, making it one of the most recognised energy brands in the country.
3. EnergyAustralia
- Owned by Hong Kong-based CLP Group
- Supplies electricity and gas to homes and businesses
- Operates Mt Piper coal station and several gas-fired plants
- Promotes carbon-neutral plans and is investing in pumped hydro storage and green hydrogen
Anecdote-worthy detail:
Anyone who’s dealt with Energy Australia customer service during a blackout knows—responses can be quick, but resolution varies by postcode!
Are they better than smaller retailers?
Not necessarily. Bigger doesn’t always mean better for your hip pocket or values.
While the Big 3 have the scale to offer stability and infrastructure support, many smaller retailers offer sharper rates, green energy, or better service.
Here’s what you should weigh up:
Pros of Big 3:
- Established infrastructure
- Often offer bundling (e.g. broadband + energy)
- More likely to have long-term fixed rate plans
Cons:
- Pricing can be higher, especially post-discount
- Less flexible with niche or custom setups
- Lower GreenPower and renewable scores compared to some independents
For comparison, retailers like Powershop, Amber, or ReAmped have gained attention for transparency, carbon-neutral plans, and innovative tech-driven pricing models.
How does an energy broker fit into all of this?
Let’s say you’re running a restaurant group in Melbourne. One site is with Origin, another with AGL. You’re too busy juggling rosters and inventory to comb through electricity bills. That’s where an energy broker comes in.
An energy broker helps you:
- Compare rates from multiple suppliers, including (but not limited to) the Big 3
- Find contract terms that match your usage (like peak/off-peak timing)
- Manage contract renewals, group discounts, and site-specific tariffs
- Cut through sales language to understand true costs
In essence, brokers give you more choice without the time sink.
How dominant are the Big 3 really?
According to the Australian Energy Regulator (AER), the Big 3 still hold the majority share across NSW, VIC, SA, and QLD. But their market control is slowly decreasing as newer, tech-savvy players enter the field.
Here’s a look at current trends:
- In Victoria, their combined share dropped from 75% in 2010 to ~50% in 2024
- In Queensland, the government-run Ergon still dominates regional areas, but Big 3 compete heavily in SEQ
- In South Australia, fierce competition from newer retailers has carved out notable market space
So, while the Big 3 aren’t going anywhere soon, customer migration is shifting the landscape.
FAQ: Common Questions About the Big 3
Q: Are the Big 3 energy retailers government owned?
A: No. All three are privately owned, although some like AGL and Origin started as public utilities.
Q: Do all three offer green energy plans?
A: Yes—but the level of investment in renewables varies. For example, Origin is increasing its clean energy spend, while AGL has faced criticism for slower coal exit timelines.
Q: Can I switch between them easily?
A: Absolutely. In most areas, switching is as simple as filling in an online form. But always check exit fees and billing cycles.
Final Thought
Australia’s energy market is big, noisy, and shifting fast. The Big 3—AGL, Origin, and EnergyAustralia—still have the size and reach to dominate. But their dominance doesn’t guarantee the best fit for your needs.
Whether you’re managing a commercial portfolio or just tired of fluctuating bills, working with an energy broker might offer the clarity and cost efficiency you’re after—without locking you into the same big-name contract year after year.