What Is This Report?
The ACCC has been monitoring Australia's National Electricity Market since 2018. This is their 14th report - and the last interim report before the inquiry wraps up in June 2026.
At Battery IQ, we read the full 60 pages so you don't have to. Below are the findings that matter most for anyone with rooftop solar, a home battery, or both.
Source: ACCC Inquiry into the National Electricity Market - December 2025
The Numbers That Matter
26.5%
on Time-of-Use plans
2.5M
paying above default caps
$221
extra/year on old plans
-27.7%
demand plan customers
Time-of-Use Plans Are Taking Over Australian Electricity
The biggest shift in the ACCC's report: Time-of-Use (ToU) electricity plans are surging. In 2024, 21% of Australian households were on ToU plans. By 2025, that jumped to 26.5% - a 26% increase in just one year.
Why This Matters for Battery Owners
ToU plans charge different rates at different times of day - typically 3-4x more during evening peak (4-9pm) than off-peak periods. This price gap is exactly what home batteries exploit: charge during cheap periods, discharge during expensive ones.
The more households on ToU plans, the more valuable batteries become. A battery on a flat-rate tariff might save you $400/year. The same battery on a well-structured ToU plan? Often $800-1,200/year.
The ACCC notes this shift is being driven by smart meter rollouts and retailer incentives. Victoria leads the nation with near-universal smart meter coverage, while other states are catching up under the AEMC's accelerated deployment rules.
2.5 Million Australians Are Overpaying. Are You?
One of the more damning findings: 36.5% of electricity customers - roughly 2.5 million households - are paying at or above the government's Default Market Offer (DMO) or Victorian Default Offer (VDO).
These "default offers" are meant to be safety nets - the maximum a retailer can charge customers who don't shop around. Yet more than a third of Australians are hitting or exceeding these caps.
Even Worse: 434,000 Are Paying 10%+ Above Default
The ACCC found 434,000 customers paying more than 10% above their reference price. These households are leaving hundreds of dollars on the table every year - before we even talk about batteries.
The report is clear: if you haven't compared energy plans in the last 12 months, you're probably overpaying. The government's Energy Made Easy comparison site is a good starting point - though it doesn't factor in battery optimisation.
The Loyalty Penalty: Old Plans Cost You $221 More Per Year
The ACCC quantified something many suspected: staying loyal to your energy retailer is expensive.
Customers who've been on the same plan for 3 or more years pay an average of $221 more annually than customers on newer plans. That's not a one-off - it compounds every year you stay put.
Loyal Customer (3+ Years)
Same plan since 2022
$221/year more
Over 10 years: $2,210+ extra
Active Switcher
Compares plans annually
Market rate
Over 10 years: Thousands saved
This reinforces what we've been saying at Battery IQ: your energy plan choice matters more than rebate timing. A battery installed on an outdated, overpriced plan won't deliver the savings you expect.
Demand Plans Are Dying - And That's a Problem
Here's an interesting trend: the number of customers on demand-based tariffs dropped 27.7% in one year, falling to just 279,000 households nationally.
Demand tariffs charge based on your peak power draw (in kW) rather than total energy use (kWh). In theory, they're ideal for battery owners - if you can manage your peaks, you slash your bills.
Why Are They Declining?
The ACCC suggests demand tariffs are simply too complex for most households to understand or manage. One accidental peak - running the air conditioner, oven, and pool pump simultaneously - can blow your monthly bill.
But batteries can solve this. Smart batteries automatically manage peaks, making demand tariffs far more attractive. This is one of the untapped opportunities for battery automation.
Meanwhile, "complex plans" (with multiple rate tiers or conditions) grew 37.7% to 462,000 customers. The electricity market is getting more complicated, not simpler.
What Does This Mean If You're Considering a Battery?
1. Your Energy Plan Is the Foundation
The ACCC data confirms what we see every day: the gap between a good and bad energy plan is often larger than the annual battery savings themselves. Get this right first - whether you buy a battery or not.
2. ToU Plans + Batteries = Best Combination
With 26.5% of households on ToU and rising, pricing structures increasingly favour those who can shift consumption. Batteries do this automatically.
3. Don't Assume Your Current Plan Is Good
If you haven't switched in 3+ years, you're statistically paying $221 more than you should - before adding battery savings. Compare first, then calculate battery ROI on your best available plan.
4. Demand Tariffs Are Underrated
While the market is abandoning demand tariffs, battery owners should investigate them. Smart batteries can manage peaks automatically - turning a "complex" tariff into a goldmine.
Why This Is Why Battery IQ Exists
Here's the uncomfortable truth: if your battery installer doesn't know anything about your retail energy plan, you're talking to the wrong people.
A battery that isn't configured for your specific tariff structure can't maximise your exports, can't time your charging properly, and can't unlock wholesale market access. You end up with an expensive box on the wall that delivers a fraction of its potential savings.
This ACCC report proves the point: millions of Australians don't understand how their bill works. Others don't believe $221/year is worth their time - but over 10 years, that's $2,200+ in unnecessary costs. And that's before the battery conversation even starts.
You need someone who looks at the whole picture: your solar, your battery, your energy plan, your hot water, your EV - all working together. That's what we do at Battery IQ.
What's Next: The ACCC Inquiry Wraps Up in June 2026
This December 2025 report is the 14th in a series that began in 2018. On 28 August 2025, the Treasurer extended the inquiry one final time.
The final report is due 30 June 2026. After 8 years of monitoring Australia's electricity market, we'll get the ACCC's concluding findings and recommendations. You can track the inquiry's progress on the ACCC's future reporting page.
Inquiry Timeline
- 2018: Inquiry begins after ACCC's Retail Electricity Pricing Inquiry
- 2018-2025: 13 reports monitoring competition, prices, and market conduct
- December 2025: 14th report (this one)
- June 2026: Final report due to the Treasurer
At Battery IQ, we'll continue to analyse these reports and translate the findings into practical advice for Australian households considering solar and battery systems.
Coming January 2026
Calculate Your Savings on the Right Plan
Share your bill and we'll show you realistic savings - factoring in your energy plan, not just battery-in-isolation numbers.
Don't have a battery yet? That's fine. We can help you decide whether a battery is right for you - and help you switch to a better energy plan even if you don't buy one.
Get Notified When We LaunchOfficial Sources
- ACCC Inquiry into the National Electricity Market - December 2025 Report
- ACCC Electricity Market Monitoring Inquiry - Future Reporting
- Australian Energy Regulator - Default Market Offer Prices
- Essential Services Commission Victoria - Victorian Default Offer
- Energy Made Easy - Australian Government Energy Comparison
- AEMC - Accelerating Smart Meter Deployment
Analysed by Battery IQ Energy Team
Published: 12 January 2026