The short answer
What actually decides whether solar panels pay off
Australia has some of the cheapest solar panels and the highest rooftop uptake on earth, yet most homeowners still choose a system the wrong way. They compare panel brands and price-per-watt, when the number that actually decides whether the system pays for itself is how much of its output they use themselves. With feed-in tariffs collapsed to a few cents, a kilowatt-hour you consume during the day is worth about six times one you export. This page explains how the solar market really prices that gap, and how to size a system around it.
Here is the core takeaway in one line: in 2026 the panels are a cheap commodity, and your payback is decided by how much of your own generation you use rather than export. A kilowatt-hour you self-consume offsets your full usage rate, around 30 c, while the same kilowatt-hour exported to the grid now earns roughly 5 c, because the network is flooded with midday solar. That six-to-one gap reframes every other decision: it makes oversizing the panel array sensible (the panels are cheap), it makes a battery, pool pump, hot-water timer or EV charger the real upgrades, and it makes a high feed-in headline rate a trap if it comes with a worse usage rate. The right question is not "which panel?" but "how much of this can I use myself?"
Reframe the assumption: most buyers optimise the wrong variable. Panel efficiency and price-per-watt vary only a little between quality systems; self-consumption can vary from 20% to 80% depending on your habits and hardware, and it is the single biggest lever on payback. Get that right and an average panel pays back fast; get it wrong and a premium panel still disappoints.
Interactive explainer
How much would solar make on your actual roof?
Enter your address. We read your real rooftop (how many panels fit, your local sunshine) and model the yearly generation, then show how self-consumption, not exports, drives the savings.
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Illustrative only. Generation uses Google Solar API rooftop modelling (or the capital-city yield if your roof is not imaged), derated 0.85 for AC and system losses. Self-consumed kWh are valued at your usage rate; exports at your feed-in tariff. System cost assumes ~$0.95/W after the STC rebate. Real results depend on orientation, shading, your tariff and habits. Sources: Google Solar API, Clean Energy Regulator, AER DMO 2025-26.
The blind spot
Why most solar panel guides lead you to the wrong system
Most articles about solar panels do three unhelpful things, and each one quietly costs buyers money.
First, they obsess over the panel. Page after page compares monocrystalline against polycrystalline, brand against brand, and the last percentage of efficiency. In 2026 the panel is the most commoditised part of the system. Two quality panels on the same roof produce within a few percent of each other. The decision that moves your bill by hundreds of dollars is system size and self-consumption, not the cell chemistry.
Second, they quote a feed-in tariff as if it were income. Older guides still talk about "earning" from exports. The mandated minimum has been scrapped in Victoria and New South Wales, and midday export rates have fallen toward zero because the grid is awash with rooftop solar at lunchtime. Treating exports as the payoff leads people to undersize for self-use and oversize for a sale that no longer pays.
Third, they quote a stale rebate. The STC discount shrinks every January as the deeming period counts down to the scheme's 2030 close. A guide written two years ago overstates today's rebate by hundreds of dollars. Numbers like these belong in a dated box, which is why every figure on this page is stamped with the date it was checked.
How the solar market actually prices your roof
Expert analysis: the machinery behind the payback
The pricing logic: a cheap asset against an expensive grid
Solar economics is a spread, not a sale. You pay roughly $0.90 to $0.95 per watt installed, after the STC rebate, for hardware that runs for 25 years. Against that, every kilowatt-hour your system makes either replaces grid power you would have bought at about 30 c, or is exported for about 5 c. The whole return lives in that difference. Because the panels are cheap and the self-use saving is large, the winning move is to install enough capacity to cover your daytime load with room to spare, then push as much of your consumption as possible into daylight hours.
The STC rebate, and why it is really a federal subsidy that shrinks
The Small-scale Technology Certificate (STC) is a tradeable certificate created when you install solar. Your installer takes them in exchange for an upfront discount, so you rarely touch them. The count is set by a simple formula: system size in kilowatts, times a regional zone factor (Zone 3 covers most capital cities at 1.382), times a deeming period that falls by one year every January. In 2026 the deeming is 5 years, so a 6.6 kW Zone 3 system earns about 45 certificates, worth roughly $1,710 at a $38 spot price. The unintended consequence is a countdown: the same system installed next year is worth a step less, and the rebate hits zero in 2030.
The 133% rule: why installers fit more panels than the inverter
Here is a structural quirk worth understanding. Accreditation rules let you connect a panel array up to 133% of the inverter's rated capacity and still claim the full rebate. So a 5 kW inverter is routinely paired with up to 6.6 kW of panels. It sounds like waste, but it is deliberate: panels only hit their rated output for a few hours around noon, so the "extra" panels fill in the mornings and afternoons, flattening the generation curve and lifting the kilowatt-hours you can actually use. The cheap part of the system is used to squeeze more value from the expensive part.
The reference price, and why it differs by state
Your usage rate, the number that sets the value of self-consumption, is anchored to a regulated reference price. In New South Wales, south-east Queensland and South Australia that is the Australian Energy Regulator's Default Market Offer (DMO). Victoria sets its own Victorian Default Offer (VDO) through the Essential Services Commission. Western Australia (Synergy) and the Northern Territory (Power and Water) sit outside the National Electricity Market entirely, with state-set tariffs and no retail competition. The higher your usage rate, the more each self-consumed solar kilowatt-hour is worth, which is why the same system pays back faster in a high-tariff network.
What this costs real households
How good systems end up underperforming
The mechanism above is not theory. It is exactly how well-meaning buyers leave money on the table.
They buy a premium panel and an undersized system
A household spends the budget on a top-tier panel badge, then keeps the array small to "match" their bill. They have optimised the variable that barely moves and skimped on the one that matters. A larger array of mainstream panels would have generated far more self-consumable power for the same money.
They size for export, then watch the tariff collapse
A buyer fits a big system expecting to "sell back" the surplus. Two tariff resets later the feed-in rate is near zero at midday, and most of that surplus now earns almost nothing. The system still makes sense, but only because of the power they use, not the power they sell.
They never shift their usage into daylight
The panels work perfectly, but the dishwasher, the pool pump and the washing run at night out of habit. Self-consumption sits at 20%, so 80% of the generation is exported for cents. A few timers and a changed routine would have doubled the saving with no extra hardware.
They forget to re-shop the plan
After install they stay on the plan they had before solar. In the competitive states a solar-specific plan, balancing a fair usage rate against the feed-in rate, would have paid more than the panels' first-year difference. The plan is part of the system.
The insider insight
The feed-in tariff is now a marketing number, not a payout
Here is the part the panel reviews never mention. Retailers in the competitive states advertise eye-catching feed-in tariffs, 10 or 12 c a kilowatt-hour, because they know it sells solar plans. But a retailer pays you for exports out of the same margin it earns on your usage. So a high feed-in rate is almost always paired with a higher usage rate or a lower discount. The headline you are drawn to is funded by the rate you actually pay on the much larger number of kilowatt-hours you import at night.
The non-obvious truth: for most homes the feed-in tariff is close to irrelevant to the result, because you export far less than you think once self-consumption is decent. The plan with the best feed-in rate is rarely the cheapest plan overall. Compare the whole bill, with your real import and a realistic export volume, not the feed-in number on the ad. The households that win treat exports as a small bonus and build everything around using their own power.
The practical consequence: a battery, an EV or a hot-water timer that lifts self-consumption is usually worth more than any feed-in rate you could chase, because it converts 5 c exports into 30 c savings.
Grounded in the analysis
What you should actually do
Specific moves that follow from how solar is priced, not generic advice.
Size for daylight, then go bigger
Cover your daytime load first, then add capacity, because the panels are the cheap part. A 6.6 to 10 kW array of mainstream panels beats a small premium system. Use the estimator above to see what your roof actually fits.
Buy self-consumption, not feed-in
Spend on the things that let you use your own power: a hot-water timer, a pool-pump schedule, daytime appliance runs, an EV charger, or a battery. Each one turns a 5 c export into a ~30 c saving. Treat the feed-in rate as a minor bonus.
Claim the rebate now, re-shop the plan
The STC rebate shrinks every January, so waiting costs you. After install, compare solar plans in VIC, NSW, SA, QLD or the ACT. In WA and NT the buyback is set by the state scheme, so the lever is sizing and timing, not switching.
See how feed-in tariffs really work by state, or whether a battery pays to lift your self-consumption.
Current figures, last updated 2026-06-15
Australian solar figures for 2026. Sources: the Clean Energy Regulator (STC scheme and zone ratings), the Solar Choice price index, IPART (NSW), the Essential Services Commission (VIC), the Queensland Competition Authority, Synergy (WA DEBS) and the Australian Energy Regulator (DMO 2025-26). Confirm current figures before purchase, as the rebate and tariffs are reviewed regularly.
The bottom line
Why this matters right now
Two trends are moving in opposite directions. Panels keep getting cheaper, while the value of exporting keeps falling as the grid fills with daytime solar and networks move toward charging for midday exports. That widens the gap between self-consumed and exported power, and it rewards a very different system from the one most guides describe. Buy a generously sized array of mainstream panels, claim the STC rebate before it steps down again, spend on the hardware and habits that lift self-consumption, and in the competitive states put it all on a solar-specific plan. Do that and the panels become almost an afterthought, which, in 2026, is exactly what they are.
Common questions
A Selectra expert answers your solar panel questions
After the federal STC rebate, installed prices sit at roughly $0.90 to $0.95 per watt for a quality system. That puts a common 6.6 kW system around $5,000 to $6,500 and a 10 kW system around $8,000 to $10,000, fully installed. Premium panels and microinverters add 20 to 30%. The panel is now the cheapest line on the quote, which is exactly why oversizing the array is standard practice.
It depends on your roof and your daytime usage, not a fixed rule. A typical home installs a 6.6 to 10 kW system, which is about 15 to 25 panels at 400 watts each. The smarter question is how much you can use during daylight: because exports earn so little, fitting more panels only pays if you can lift self-consumption with a battery, a pool, hot water on a timer or an EV. The estimator above reads your actual rooftop to show how many panels fit.
The Small-scale Technology Certificate (STC) rebate is a federal discount applied upfront by your installer. In 2026 the deeming period dropped to 5 years, so a 6.6 kW system in Zone 3 (most capital cities) earns about 45 certificates worth roughly $1,710 at a $38 spot price. The value falls a step every January as the scheme winds down to zero in 2030, so each year you wait the rebate shrinks.
Less and less. There is no longer a mandated minimum in Victoria or New South Wales, and many retailers pay close to 0 c/kWh for midday exports because the grid is flooded with cheap solar. A few offer 8 to 12 c in the evening peak. The lesson is structural: build your system to use power, not to sell it. A high feed-in headline rate often hides a worse usage rate, so always compare the whole plan.
For almost everyone, a mainstream Tier-1 monocrystalline panel from a financially stable manufacturer, paired with a quality inverter and a Clean Energy Council accredited installer, is the right call. Chasing the last 1 to 2% of efficiency rarely changes the payback, because output is dominated by roof orientation, shading and how much you self-consume. Spend your money on a bigger array and a good installer, not on a premium panel badge.
Yes, and you should review your plan the moment solar is switched on. In Victoria, New South Wales, South Australia, Queensland and the ACT you can choose your retailer and compare solar-specific plans. In Western Australia (Synergy) and the Northern Territory (Power and Water) there is no retail competition, so the buyback is set by the state scheme rather than chosen. Wherever you are, the plan that looks best without solar is rarely the best one with it.
