Electricity Plan vs Rooftop Solar vs Battery: Australia Breakeven 2026

Would you take a guaranteed return of around 15 percent a year, tax free, on A$6,500? That is roughly what a 6.6 kW rooftop system in Sydney pays an owner-occupier family in 2026 on the assumptions set out below, even with feed-in tariffs down at 3 to 4 cents per kilowatt-hour and AGL removing them from standing offers entirely. And yet the question most households are still asking is a different one: which electricity retailer is cheapest? That question is worth answering, and the Australian Energy Regulator's data says the answer is worth A$350 to A$500 a year. But it is the smaller question.

This article does the arithmetic for both. It takes the AER's 2026-27 Default Market Offer, effective 1 July 2026, as the baseline bill; IPART's 2026-27 feed-in benchmark and the retailers' published rates as the export price; 2026 solar and battery pricing from SolarQuotes and the industry guides; and four stated self-consumption scenarios, a working family, a retiree couple, a small household and an EV owner. Every assumption is written down so you can swap in your own numbers. The conclusion, in short: switch retailer this week, put panels on the roof this winter, and only buy the battery if you are on a time-of-use tariff or want the resilience.

The four options at a glance

Persona for the table: an owner-occupier family of four in the Ausgrid zone (Sydney), using 5,500 kWh a year, north-facing roof, currently on a flat-rate market plan.

	Stay on a market electricity plan	Add 6.6 kW solar	Add 10 kW solar	Add 6.6 kW solar plus 13.5 kWh battery
Upfront cost	A$0	About A$6,500 after STC discount (2026 guides: A$4,800 to A$7,900)	About A$10,000 after STC discount (SolarQuotes, August 2026 average; range A$7,000 to A$20,000)	About A$16,500 (A$6,500 solar plus Tesla Powerwall 3 at about A$10,000 after federal rebate, SolarQuotes May 2026)
What is included	Usage, supply charge, metering	Panels (25-year warranty), inverter (10-year), installation, STC discount	Same, larger array	Same plus battery (10-year warranty), gateway, Cheaper Home Batteries discount
Annual bill before any change (DMO reference)	A$1,899 at AER usage assumption; higher at 5,500 kWh
Annual saving on the assumptions below	A$350 to A$500 by moving from DMO to a market plan	About A$952 (flat tariff, 40 percent self-consumption, 4-cent feed-in)	About A$1,148 (same, with surplus exported at 4 cents)	About A$1,596 (85 percent self-consumption, flat tariff)
Simple payback	Immediate	6.8 years	8.7 years	10.3 years on the combined spend; 15.5 years on the battery increment alone
Exit or lock-in	Benefit period may expire; no exit fee on most plans	None; system stays with the house and adds to resale	None	None
The catch	Saving is one-off and shrinks when the benefit period ends	Low feed-in means you must use it, not sell it	Extra panels only pay if you have daytime load	Battery pays only on time-of-use pricing or with a VPP

Sources: AER DMO 2026-27 final determination; IPART feed-in benchmark fact sheet 2026-27; Energy Matters' July 2026 NSW retailer round-up; SolarQuotes cost pages (28 August 2026 and 12 May 2026); the whysolar and solarxenergy 2026 price guides. All read in September 2026. The self-consumption and usage-rate assumptions are the author's and are set out in the next section.

What is the actual baseline bill in 2026?

The Default Market Offer is the regulated cap on standing offers in New South Wales, south-east Queensland and South Australia, and the reference price every market plan must quote against. The AER's final determination for 2026-27, in force since 1 July 2026, set residential flat-rate prices at A$1,899 in the Ausgrid zone (down A$66, or 3.4 percent), A$2,328 in Endeavour (down A$83), A$2,604 in Essential Energy (down A$137, or 5 percent), A$1,988 in Energex (down A$155, or 7.2 percent) and A$2,334 in SA Power Networks (up A$33, or 1.4 percent). Each is calculated on the AER's standard annual usage assumption for the zone, which for Ausgrid is lower than the 5,500 kWh family in this article uses. Victoria's Essential Services Commission set the 2026-27 Victorian Default Offer at A$1,481 to A$1,748 for a 4,000 kWh household depending on the distribution zone, about 5 percent lower than the year before.

Almost nobody should be paying the DMO. The AER reports market offers 18 to 27 percent below it, which in the Ausgrid zone means the best plans on Energy Made Easy land around A$1,400 to A$1,550 for the reference household. That gap is the first saving, it needs no installer, and it is the one every renter and apartment dweller can take.

The assumptions behind every number in this article

Usage rate: 30 cents per kWh. Derivation: the Ausgrid DMO of A$1,899 on the AER's usage assumption implies an all-in rate in the high 30s of cents once a daily supply charge of roughly A$1.20 is stripped out; a market plan 20 percent below the DMO brings the usage component to about 30 cents. Supply charge: unchanged by solar, so it is left out of the savings maths.

Feed-in tariff: 4 cents per kWh, the lower-middle of IPART's 3.4 to 6.5 cent 2026-27 benchmark. EnergyAustralia's flat NSW rate was 3 cents and Alinta and GloBird were at 10 cents in July 2026, so a 10-cent sensitivity is shown where it matters.

Generation: 26 kWh a day for a 6.6 kW system in New South Wales, about 9,500 kWh a year, per the 2026 industry guides (Queensland and Western Australia about 30, Victoria about 22, Tasmania about 20). A 10 kW system scales to about 14,400 kWh.

System prices: A$6,500 for 6.6 kW, A$10,000 for 10 kW, A$10,000 for a 13.5 kWh Tesla Powerwall 3 installed with gateway after the federal rebate, A$8,800 for a 12.8 kWh Sungrow (SolarQuotes, May and August 2026).

Self-consumption: the share of the household's own consumption that solar covers directly. 40 percent for a working family, 60 percent for a retiree couple at home, 45 percent for a small household with low use, 55 percent for an EV household charging by day, 85 percent with a battery.

Payback is simple, undiscounted, and ignores both panel degradation (about 0.5 percent a year) and electricity price inflation; those two roughly offset.

Is solar worth it for a family of four that is out all day?

The persona from the table: 5,500 kWh a year, out on weekdays, home on weekends, 40 percent self-consumption once the dishwasher and washing machine are on daytime timers.

6.6 kW: solar covers 2,200 kWh at 30 cents, A$660; exports 7,300 kWh at 4 cents, A$292. Saving A$952 a year, payback 6.8 years on A$6,500. At a 10-cent feed-in tariff the export line becomes A$730 and the saving A$1,390, a 4.7-year payback.

10 kW: solar covers the same 2,200 kWh (the house cannot use more by day), A$660; exports 12,200 kWh at 4 cents, A$488. Saving A$1,148, payback 8.7 years on A$10,000. The extra A$3,500 of panels earns A$196 a year. Not worth it for this family unless they are about to buy an EV or a heat pump.

The market-plan switch, by contrast, is worth A$350 to A$500 once. Both. Do both.

Is solar worth it for a retiree couple who are home all day?

A couple in their seventies in the Endeavour zone (western Sydney), 4,500 kWh a year, home most days, ducted air conditioning in summer afternoons, 60 percent self-consumption.

6.6 kW: covers 2,700 kWh at 30 cents, A$810; exports 6,800 kWh at 4 cents, A$272. Saving A$1,082, payback 6.0 years. On the Endeavour DMO of A$2,328 the solar system removes close to half the bill, and because the couple is home, the self-consumption number is real rather than aspirational.

This is the best-case household for solar without a battery, and the worst case for a battery: there is little evening load left to shift, so the battery would mostly be storing energy for a 4-cent export in the morning.

Is solar worth it for a small household using 2,500 kWh a year?

A single owner in a two-bedroom townhouse in the Energex zone (Brisbane), 2,500 kWh a year, 45 percent self-consumption.

6.6 kW generates about 11,000 kWh a year in Brisbane (30 kWh a day). It covers 1,125 kWh at 30 cents, A$338; exports 9,875 kWh at 4 cents, A$395. Saving A$733, payback 8.9 years on A$6,500. Still positive, but the system is oversized for the house. Because inverter and labour costs are largely fixed, a smaller array saves less than it looks on a quote; the better lever for this household is a 10-cent feed-in retailer, which lifts the export line to A$988 and the saving to A$1,326 (4.9 years). This is the one persona where the feed-in tariff, not self-consumption, decides the answer, and it is worth shopping retailers for it.

Is solar worth it for an EV owner?

A family in the SA Power Networks zone (Adelaide) with a BYD Atto 3, 9,000 kWh a year including about 2,500 kWh of car charging, able to charge on weekends and one work-from-home day, 55 percent self-consumption.

10 kW generates about 14,000 kWh a year in Adelaide. It covers 4,950 kWh at 30 cents, A$1,485; exports 9,050 kWh at 4 cents, A$362. Saving A$1,847, payback 5.4 years on A$10,000. South Australia's DMO rose 1.4 percent to A$2,334 this year, the only region to go up, which widens the gap further. The EV is what turns the 10 kW system from a vanity array into the right size: every 1,000 kWh of charging moved from the grid to the roof is worth A$260 a year at these rates.

When does a battery pay?

Take the family of four again and add a 13.5 kWh battery at A$10,000. Self-consumption rises from 40 to 85 percent of 5,500 kWh, moving 2,475 kWh a year from 4-cent export to 30-cent self-use. Net gain 26 cents per kWh, A$644 a year, 15.5-year payback. The battery warranty is 10 years. On a flat tariff this does not work.

On a time-of-use tariff with a 50-cent evening peak (which is roughly where the IPART time-of-day benchmark suggests the grid values 4pm to 9pm electricity, at 17 to 19 cents on the export side alone), the shifted 2,475 kWh is worth 46 cents net, A$1,139 a year, an 8.8-year payback. Add a virtual power plant payment and it tightens again. The Cheaper Home Batteries Program still discounts the battery, but since 1 May 2026 the discount is tiered and the STC factor fell from 8.4 to 6.8, so the effective May to December 2026 rate of about A$272 per kWh is A$600 to A$800 less generous on a 10 to 13 kWh unit than it was in April.

So the battery decision is a tariff decision first. If your retailer offers a time-of-use plan with a real evening peak and you can shift load, the battery is close to paying inside its warranty. If you are on a flat tariff and home all day, it is a blackout-resilience purchase, and that is a fine reason, just not a financial one.

What actually moves the bill

Self-consumption. The single biggest lever. Every 1,000 kWh moved from evening grid use to midday solar use is worth A$260 a year at a 30-cent usage rate and a 4-cent feed-in. Timers on the dishwasher, washing machine, pool pump and hot water system are the cheapest solar upgrade you can buy.

The feed-in tariff. Matters for small households and oversized systems, not for families. The spread between EnergyAustralia's 3 cents and Alinta's or GloBird's 10 cents is worth A$511 a year to a household exporting 7,300 kWh.

The usage rate. Flat versus time-of-use. Time-of-use punishes evening use and rewards solar plus battery; flat rewards daytime-home households and makes a battery hard to justify.

The DMO gap. Moving from a standing offer to the best market plan is worth 18 to 27 percent, on the AER's figures, before any panel goes up.

System size versus load. A 6.6 kW array is the floor because fixed costs dominate; every kilowatt above it pays only if daytime load exists to absorb it.

Roof orientation. North is best for total yield; west-facing panels generate later in the afternoon, which lifts self-consumption for working households and is often the better choice at a 4-cent feed-in.

The rebates. The STC discount steps down each January; the battery discount stepped down on 1 May 2026 and is tiered above 14 kWh.

When should you switch plans, and when should you install?

Switch retailer now, and again whenever a benefit period ends; Energy Made Easy lists every generally available plan and the AER requires retailers to show the percentage difference from the reference price. Install solar in winter, when installers are quiet and the commissioning date lands before the spring generation peak. Buy the battery when you have a time-of-use tariff to arbitrage, a VPP offer in hand, or a resilience need, and not before.

Verdict by buyer type

Renter or apartment owner: switch to the best market plan on Energy Made Easy; A$350 to A$500 a year in the Ausgrid zone. Ask strata about shared solar.

Family of four, out by day: market plan plus 6.6 kW solar with appliance timers; 6.8-year payback, 4.7 years with a 10-cent feed-in retailer.

Retiree couple, home by day: 6.6 kW solar, flat tariff, no battery; 6-year payback and close to half the bill gone.

Small household under 3,000 kWh: 6.6 kW only with a 10-cent feed-in retailer; otherwise the plan switch alone.

EV or heat pump household: 10 kW solar sized to the daytime load; 5.4-year payback in Adelaide on the assumptions above.

Time-of-use household with evening load, or anyone who needs power through outages: solar plus battery; 8.8-year payback on a 50-cent peak, longer on flat.

Where cashback fits

The solar quote is the one purchase in this article where cashback via ShopBack applies directly. Solar Sumo, an Australian marketplace that matches homeowners with accredited installers for rooftop solar, batteries and energy consultations, is a ShopBack Australia merchant as of September 2026. Open the ShopBack app or the Cashback Buddy browser extension, go to the Solar Sumo page on ShopBack, click through, and complete the quote request in that same session; cashback via ShopBack tracks at the rate shown on the merchant page that day and is confirmed once Solar Sumo reports the qualifying action, which for lead-based merchants can take several weeks.

The electricity retailers compared here are discussed editorially. Whether AGL, Origin, EnergyAustralia, Red Energy or any other retailer is a ShopBack merchant on a given day is shown in the app, and where one is, the same click-through mechanism applies to a new connection or a switch. Cashback does not change the tariff, the feed-in rate or the quote; it is a rebate paid on top, so it belongs at the end of the decision as a tiebreaker between two installers or two plans that are already close.

FAQ

What is the Default Market Offer and how does it relate to the plan I am actually on?

The Default Market Offer (DMO) is the capped standing-offer price the Australian Energy Regulator sets each July for households in New South Wales, south-east Queensland and South Australia who have never chosen a market plan, and it doubles as the reference price every market plan must be quoted against. For 2026-27, effective 1 July 2026, the AER's final determination put the residential flat-rate DMO at A$1,899 a year in the Ausgrid zone, A$2,328 in Endeavour, A$2,604 in Essential Energy, A$1,988 in Energex and A$2,334 in SA Power Networks, each on the AER's standard usage assumption for that zone. Victoria's equivalent, the Victorian Default Offer set by the Essential Services Commission, ranges from A$1,481 to A$1,748 for a 4,000 kWh household in 2026-27. Market plans typically sit 18 to 27 percent below the DMO according to the AER, so the plan you are on, if you ever switched, is almost certainly cheaper than these figures, and the gap between the DMO and the best market offer on Energy Made Easy is the first and cheapest saving in this whole article.

How much does a 6.6 kW solar system cost in Australia in 2026?

Between roughly A$4,800 and A$7,900 fully installed after the federal small-scale technology certificate (STC) discount, based on 2026 industry pricing guides, with most metropolitan quotes for a quality tier-one panel and inverter package landing between A$5,500 and A$7,500. The STC discount is applied at the point of sale and for a 6.6 kW system in 2026 is worth roughly A$1,500 to A$2,200 depending on your postcode zone and the certificate price. A 10 kW system averaged around A$10,000 installed on SolarQuotes' August 2026 data, with a wide A$7,000 to A$20,000 range driven by panel brand, inverter and roof complexity. Queensland and Western Australia tend to be cheapest; Tasmania and the Northern Territory dearest. The breakeven maths in this article uses A$6,500 for 6.6 kW and A$10,000 for 10 kW in Sydney.

How does the feed-in tariff work and why is it so low now?

The feed-in tariff is what your retailer pays you per kilowatt-hour of solar you export to the grid instead of using. It is low because midday wholesale electricity is now close to worthless on sunny days: with more than 4 million Australian homes on solar and 1 GW of rooftop capacity added in the June 2026 quarter alone, according to the Clean Energy Regulator, the grid is flooded at noon. IPART's all-day benchmark for New South Wales in 2026-27 is 3.4 to 6.5 cents per kWh, down from 4.8 to 7.3 cents the year before, and it is a voluntary guide, not a floor. Retailers set their own rates: EnergyAustralia cut its flat NSW rate to 3 cents, AGL removed feed-in tariffs from its standard retail contracts, and Alinta and GloBird were advertising 10 cents in mid-2026, per Energy Matters' July 2026 round-up. Victoria stopped setting a minimum feed-in tariff altogether from 1 July 2025. IPART's time-of-day benchmark pays 17.2 to 18.7 cents in the Ausgrid 4pm to 9pm window, which is the only export rate that moves the maths, and that window is exactly when a battery, not a panel, is doing the exporting.

Is rooftop solar cheaper than staying on the best electricity plan in 2026?

For an owner-occupier with a north- or west-facing roof and daytime consumption, yes, and comfortably. Take a Sydney family using 5,500 kWh a year on a market plan at an assumed 30 cents per kWh usage rate. A 6.6 kW system generating about 26 kWh a day, or roughly 9,500 kWh a year, that covers 40 percent of the household's use saves 2,200 kWh at 30 cents, or A$660, and exports the remaining 7,300 kWh at 4 cents for A$292, a total of A$952 a year. On a A$6,500 system that is a 6.8-year simple payback, and at a 10-cent feed-in tariff it drops to 4.7 years. The system is warranted for 25 years on the panels and 10 on the inverter, so even the slow case returns the capital more than three times over. The best electricity plan, by contrast, saves a one-off 18 to 27 percent against the DMO and then stops; the two are not rivals, they stack, and the right answer is to do both.

Is a battery cheaper than exporting solar at 4 cents?

On a flat tariff, not yet; on a time-of-use tariff, often. A 13.5 kWh Tesla Powerwall 3 installed with its gateway cost about A$10,000 after the federal rebate in SolarQuotes' May 2026 pricing, and a 12.8 kWh Sungrow around A$8,800. For the Sydney family above, a battery lifts the share of household use covered by solar from about 40 to about 85 percent, which shifts roughly 2,475 kWh a year from 4-cent export to 30-cent self-use, a gain of 26 cents per kWh or about A$644 a year. That is a 15.5-year payback on A$10,000, longer than the 10-year warranty. On a time-of-use plan with an evening peak around 50 cents, the same 2,475 kWh is worth 46 cents net, or about A$1,139 a year, and the payback falls to 8.8 years. Add a virtual power plant payment or the Ausgrid time-of-day feed-in benchmark of 17 to 19 cents for evening export and it falls further. So the battery is a time-of-use decision: without a peak tariff to arbitrage it is a resilience purchase, not a financial one.

When is the best time of year to install solar?

Winter, for two reasons. Installers are quieter between May and August, which is when quotes are keenest and lead times shortest, and a system commissioned in July captures the full spring and summer generation peak from the first month. The STC discount also declines slightly each 1 January as the scheme winds toward 2030, so a system installed in December earns marginally more certificate value than the same system in January. For batteries, the Cheaper Home Batteries Program changed on 1 May 2026: the STC factor fell from 8.4 to 6.8, the discount became tiered (full rate on the first 14 kWh of usable capacity, 60 percent of the rate from 14 to 28 kWh, 15 percent from 28 to 50 kWh), and the effective discount for May to December 2026 is around A$272 per kWh, which for a 10 to 13 kWh battery cut the rebate by roughly A$600 to A$800 against the pre-May rate. The program continues, so there is no cliff, but every scheduled step-down makes the same battery slightly dearer than the quarter before.

When does a 10 kW system make more sense than 6.6 kW?

When the household can use the extra generation, which in 2026 means an electric vehicle charged in daytime, a heat pump hot water system on a daytime timer, or a battery. At a 4-cent feed-in tariff, the extra 3.4 kW of panels on a 10 kW system generates about 4,900 kWh more a year in Sydney and, if all of it is exported, earns only A$196 a year for roughly A$3,500 of extra cost, an 18-year payback that is not worth it. Put a BYD Atto 3 or a Tesla Model Y on a daytime charger and absorb 3,000 of those kilowatt-hours at 30 cents instead and the extra panels earn A$900 a year, a 3.9-year payback on the increment. The rule of thumb: size the system to the daytime load you can create, not the roof you have. A 6.6 kW system is the floor because inverter and installation costs are largely fixed; going bigger only pays if you can self-consume.

Can I get cashback via ShopBack on solar or on my electricity plan?

On the solar side, yes: Solar Sumo, an Australian solar and battery quotes marketplace that connects homeowners with accredited installers, is a ShopBack Australia merchant as of September 2026, so starting your quote process through the Solar Sumo page on ShopBack earns cashback via ShopBack at the rate published on that page at the time, once the qualifying action is confirmed. The electricity retailers compared here (AGL, Origin, EnergyAustralia, Red Energy, Alinta, GloBird) are discussed editorially; whether any retailer is a ShopBack merchant on a given day is shown on the ShopBack app, and if one is, the same click-through mechanism applies. Cashback never changes the quote, the tariff or the feed-in rate; it is a rebate on top, confirmed after the merchant reports the sale.

Does solar still save money if nobody is home during the day?

Yes, but less, and this is the case where the assumptions matter most. A household that is out from 8am to 6pm might self-consume only 20 to 25 percent of a 6.6 kW system's output: on 5,500 kWh of annual use that is around 1,200 kWh saved at 30 cents, or A$360, plus roughly 8,300 kWh exported at 4 cents, or A$332, a total of A$692 and a 9.4-year payback on A$6,500. Still positive, but the fix is cheap: run the dishwasher, washing machine and pool pump on timers between 10am and 3pm, set the hot water system to heat at midday, and pre-cool the house at 2pm in summer. Each 1,000 kWh you move from evening to midday is worth A$260 a year at a 30-cent usage rate and a 4-cent feed-in. Two or three appliance timers routinely take a working household from 25 percent to 40 percent self-consumption, which is the difference between a nine-year and a seven-year payback.

What if I rent or live in an apartment and cannot install solar?

Then the comparison collapses to the electricity plan, and that is still worth a few hundred dollars a year. The AER's data shows market offers 18 to 27 percent below the DMO, so a renter in the Ausgrid zone on a standing offer at A$1,899 can usually find a market plan around A$1,400 to A$1,550 on Energy Made Easy, a saving of A$350 to A$500 for twenty minutes of work and no installer. Check three things: whether the plan is flat or time-of-use (time-of-use suits people who are out in the evening peak, flat suits people who are home), whether there is a benefit period after which the discount expires, and whether a GreenPower or carbon-neutral option costs extra. Apartment owners in strata should also ask whether the building is in an embedded network, which changes who they can buy from, and whether the owners corporation has looked at a shared solar system with allocation to individual lots, which several Australian suppliers now offer.

Key takeaways

The electricity plan and the roof are not competing answers. The plan switch is worth 18 to 27 percent of the DMO once and takes twenty minutes; a 6.6 kW system is worth A$700 to A$1,100 a year for 25 years on a A$6,500 outlay, paying back in six to nine years depending on how much of it you use at home. Feed-in tariffs at 3 to 4 cents mean the game is self-consumption, so size the array to the daytime load you can create and put timers on everything. A battery pays inside its warranty only on a time-of-use tariff with a real evening peak or with a VPP income; on a flat tariff it is resilience, not return. Start the solar quote through Solar Sumo on ShopBack for cashback via ShopBack on top, then pick the installer on the warranty and the panel, not the rebate.