Solar Payback Calculator — South Australia (2026)
South Australia has the highest retail electricity prices in the country — and the fastest solar payback. This calculator is pre-set with Adelaide's 2026 install prices, tariffs and feed-in rates. Adjust any input and the result updates instantly. Figures are for South Australia, Australia, in 2026.
In South Australia, a 6.6 kW solar system pays back in about 2.8 years — the fastest mainland state: it costs about $6,270 after the $1,801 STC rebate, generates about 10,230 kWh a year, and saves about $2,251 a year — roughly a 36% annual return and about $38,742 net over 20 years. Change your system size, power price and daytime usage below to recompute for your home.
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Your estimated payback
In South Australia, a 6.6 kW system pays back in about 2.8 years, saving about $2,251 a year for a net cost of about $6,270 after rebates.
Estimate only — not financial advice. Figures are indicative and depend on your retailer, usage pattern and final install quote.
Why solar pays back fastest in South Australia
South Australia is the best-case state for rooftop solar payback in 2026, and the reason is simple: it has the highest retail electricity prices in the country, around 34 cents per kilowatt-hour. Because solar payback in 2026 is driven almost entirely by self-consumption — the power you generate and use yourself instead of buying from your retailer — every kilowatt-hour an Adelaide household consumes from its own panels is worth more than in any other state. A 6.6 kW system pays for itself in roughly 2.8 years here, near the front of the national pack alongside Queensland and Western Australia.
The flip side of SA's solar story is its feed-in tariff, which is effectively gone. South Australia never mandated a minimum FiT, and retailer offers for exported power now sit at just 2 to 5 cents per kilowatt-hour. SA pioneered "solar sponge" pricing — cheap or even negative wholesale prices in the middle of the day when rooftop solar floods the grid — and the state is rolling out midday export charges through its smarter-homes and flexible-export rules, meaning exporting at noon can soon cost you rather than pay you. This makes the lesson blunt: in SA you win by using your solar, not selling it. Running the pool pump, dishwasher, washing machine and hot-water system during daylight, and shifting as much load as possible into the middle of the day, is the single biggest lever on your payback.
Install prices and generation in Adelaide
SA install prices are competitive — roughly $870 to $1,030 per kilowatt fully installed after the STC rebate, so a quality 6.6 kW system lands around $6,000 to $6,500 net. Adelaide receives about 4.7 peak-sun-hours a day, giving a yield near 1,550 kWh per installed kW per year — higher than Melbourne, a little below Brisbane and Perth. Paired with the high tariff, that healthy generation is what compresses payback below three years.
The battery case is strong in SA
Because daytime exports earn almost nothing while evening grid power costs the most in the nation, a battery has an unusually strong case in South Australia. The federal Cheaper Home Batteries rebate (about $252 per usable kWh at the full rate from 1 May 2026) stacks with South Australia's VPP battery incentive of up to about $2,050, cutting the upfront cost meaningfully. A battery stores midday solar — energy that would otherwise be exported for a few cents or even charged for — and discharges it against the ~34c evening tariff, the most valuable arbitrage available anywhere in Australia. Toggle the battery on in the calculator to see how it reshapes your numbers.
The bottom line for an Adelaide household: high tariffs plus respectable sun make South Australia the fastest mainland payback, the feed-in tariff is no longer part of the equation, and a battery is more worthwhile here than in any other state.
South Australia solar figures — 2026
These are the indicative Adelaide-metro defaults this calculator uses for South Australia. You can override any of them above.
| Install price (after STC) | ~$950/kW ($870–$1,030 band) |
|---|---|
| Retail electricity price | ~34 c/kWh (highest in Australia) |
| Feed-in tariff | ~2–5 c/kWh (no mandated minimum; solar-sponge) |
| Generation yield (Adelaide) | ~1,550 kWh per kW per year |
| STC zone rating | Zone 3 (1.382) |
| Battery help | Federal ~$252/kWh + SA VPP up to ~$2,050 |
| Typical payback (6.6 kW, 60% self-use) | ~2.8 years |
South Australia solar FAQ
How fast does solar pay back in South Australia?
A 6.6 kW system in Adelaide costs about $6,270 after the $1,801 STC rebate and saves roughly $2,251 a year at SA's ~34c/kWh tariff with 60% daytime self-use, paying back in about 2.8 years. SA's high retail prices make every self-consumed kilowatt-hour worth more than anywhere else.
What is the solar feed-in tariff in SA in 2026?
South Australia has no mandated minimum feed-in tariff, and retailer offers are low — typically 2 to 5 cents per kilowatt-hour. Under "solar sponge" pricing midday exports are worth almost nothing, and some networks are introducing charges for exporting in the middle of the day.
Is there a battery rebate in South Australia?
Yes. The federal Cheaper Home Batteries rebate (about $252 per usable kWh from 1 May 2026) applies, and SA's virtual power plant battery incentive can add up to about $2,050. A battery is especially valuable in SA because it shifts low-value midday export into high-value evening self-consumption against the country's highest tariffs.
Why is SA payback faster than Victoria's?
SA pays back in about 2.8 years versus roughly 4.4 years in Victoria. SA's tariff is ~34c/kWh against Victoria's ~27c, Adelaide gets more sun than Melbourne, and install prices are lower — and because payback is now driven by avoided retail cost, the high tariff is decisive.
Compare with other states
Compare payback across every state on the hub. Victoria →
The wedge contrast: VIC scrapped its feed-in floor in 2025 and pays back in ~4.4 years. Western Australia →
The other high-tariff, high-yield state — payback ~2.8 years. Queensland →
The other fast-payback state — cheapest installs, ~2.7 years.
Methodology & sources
Data last verified: · formula_version 2026.1
This calculator uses the self-consumption-dominant model that reflects 2026 conditions. The formula is:
- STC rebate = system kW × zone rating (1.382) × deeming years (5) × STC price ($39.50)
- Net cost = system kW × install $/kW (your after-STC price); a battery adds its capex net of the Cheaper Home Batteries rebate
- Annual generation = system kW × generation per kW per year (Adelaide ~1,550)
- Annual savings = self-used kWh × power price + exported kWh × feed-in tariff (+ battery arbitrage value)
- Payback = net cost ÷ annual savings
Worked example (South Australia default): 6.6 kW × 1.382 × 5 × $39.50 ≈ $1,801 rebate. Generation ≈ 6.6 × 1,550 = 10,230 kWh/yr. At 60% self-use and 34c/kWh, plus 40% export at 4c, annual savings ≈ $2,251. Net cost ≈ $6,270 → payback ≈ 2.8 years.
Key solar terms, defined
- Solar payback period
- The number of years it takes for the money a system saves to add up to its net cost — net cost divided by annual savings.
- Self-consumption
- The share of the power your panels generate that you use on-site instead of exporting; in high-tariff SA it is where almost all the value sits.
- STC rebate
- The federal small-scale technology certificate discount, claimed by your installer as an upfront price cut on the panels.
- Deeming period
- The number of future years of generation the STC scheme credits you for upfront — 5 years in 2026, dropping by one each year to 2030.
- Solar-sponge pricing
- SA's midday tariff structure that makes exported solar near-worthless when rooftop generation floods the grid — and can even charge for it.
Sources
- STC price & deeming — Clean Energy Regulator (clearing-house $40 ex-GST; deeming 5 yr in 2026), pulled 2026-06-27.
- Install prices — SolarChoice Price Index, June 2026 (SA $870–$1,030/kW).
- Electricity price — Canstar / Finder average price per kWh (SA highest ~34c).
- Feed-in tariff — no mandated SA minimum; daytime 2–5c under solar-sponge pricing, per Solar feed-in tariffs by state, 2026.
- Generation yield — SolarChoice / Bureau of Meteorology peak-sun-hours (Adelaide ~4.7 PSH).
- Battery rebate — DCCEEW Cheaper Home Batteries Program (~$252/kWh from 1 May 2026) + SA VPP incentive up to ~$2,050.
We re-check these figures on a regular schedule and update the verified date only when a value genuinely changes. Estimate only — not financial advice.