A 6.6 kW rooftop solar system in NSW costs around $5,000-$6,000 after the federal STC rebate, saves a typical household roughly $1,200-$1,500 per year, and pays back in 4-5 years. This page has an instant payback estimator that adjusts for your state, usage, current electricity rate, and feed-in tariff.
Solar payback estimator
Indicative 2026 figures. Check energy.gov.au and solarquotes.com.au for current rebate values before signing a contract.
How solar payback actually works
Your solar panels save you money in two ways: self-consumption (electricity you generate and use yourself, avoiding the grid rate of 28-42c/kWh) and export (electricity you send to the grid, earning a feed-in tariff of 4-8c/kWh). The gap between those two numbers is huge, so payback is heavily driven by how much of your generation you use yourself.
A typical Australian household without a battery self-consumes about 25-40% of what their solar generates. If you’re home during the day (retired, working from home, EV charging during daylight), you can push this higher. If you’re at work 9-5 and the system is running to an empty house, you’ll be closer to 20-25%.
2026 state-by-state figures
| State | Avg grid rate (c/kWh) | Typical feed-in tariff (c/kWh) | Daily gen per kW (kWh) |
|---|---|---|---|
| NSW | 32 | 5 | 4.0 |
| VIC | 28 | 5 | 3.7 |
| QLD | 30 | 6 | 4.4 |
| WA | 32 | 8 (DEBS) | 4.5 |
| SA | 42 | 4 | 4.4 |
| TAS | 29 | 8 | 3.5 |
| ACT | 28 | 8 | 4.0 |
| NT | 30 | 8 | 4.9 |
Feed-in tariffs are dropping across every state in 2026 – what your retailer offers now may be lower than a year ago. Compare retailers.
The federal STC rebate explained
Every rooftop solar install in Australia gets Small-scale Technology Certificates (STCs) that the installer claims and passes back to you as a discount. The rebate is roughly:
- 5 kW: ~$1,200 rebate
- 6.6 kW: ~$1,600 rebate
- 10 kW: ~$2,400 rebate
- 13 kW: ~$3,100 rebate
The scheme is phased out at the end of 2030, and the “deeming period” (which sets how many years of certificates you can claim upfront) drops by 1 year each year. That means installing in 2026 gets less than 2025, which got less than 2024. Waiting doesn’t pay.
Typical prices by system size (2026 metro, quality installer)
| System size | Panels | Before STC | After STC |
|---|---|---|---|
| 5 kW | ~12 x 415W | $5,500 | $4,300 |
| 6.6 kW | ~16 x 415W | $6,800 | $5,200 |
| 8 kW | ~19 x 415W | $8,200 | $6,300 |
| 10 kW | ~24 x 415W | $10,500 | $8,100 |
| 13 kW | ~31 x 415W | $13,500 | $10,400 |
| 15 kW | ~36 x 415W | $15,500 | $11,900 |
Prices assume tier-1 panels + reputable inverter (Fronius, SMA, Sungrow) + CEC-accredited installer. Cheap installers can be 25-30% lower but come with real warranty and safety risk.
Should I get a battery?
For most households without electric vehicles or high daytime use, battery payback is slower than solar alone – typically 10-15 years vs 4-5 years for solar. That said, the federal Cheaper Home Batteries Program launched in July 2025 knocks 30% off battery cost, which dramatically improved the maths.
→ Use our battery payback calculator to see if adding a battery makes sense for your situation.
What affects your payback the most
- Self-consumption ratio: The single biggest lever. Every 10 percentage points of extra self-consumption typically shortens payback by 6-12 months.
- Roof orientation: North-facing is best. West-facing generates less at midday but more in the late afternoon – often better for households home in the evening. East-facing is worst for payback (peaks before you’re home).
- Shading: Even partial shade on a few panels can slash total generation by 20-30% if the system uses string inverters. Microinverters or DC optimisers mitigate this at extra cost.
- Feed-in tariff trajectory: Every major state is cutting FiT in 2026-2028. Longer term, exported solar will approach zero value – which is what makes batteries and EV charging strategies attractive.
- Installer quality: A 5% cheaper installer with a 12-month warranty vs a mid-range installer with a 10-year workmanship warranty is almost never worth it. Solar warranty claims are common by year 5-7.
Frequently asked questions
How long do solar panels actually last?
Modern panels come with 25-year performance warranties, typically guaranteeing at least 80-85% output at year 25. Real-world data suggests good panels degrade about 0.5% per year, so year 20 you’re still at ~90% output. Inverters last 10-15 years and usually need replacement once during the panel lifetime (add $1,500-3,000 to your 25-year total).
What size system should I get?
Rule of thumb: match daily generation to daily usage plus 30-50%. A household using 20 kWh/day in NSW (4 kWh/kW/day generation) matches at ~5-6.6 kW. Oversizing to 10 kW is worthwhile if you plan to add an EV or battery within 3 years, or if your roof has room and export tariff is decent.
Should I wait for cheaper panels / better rebates?
Panel prices have been flat since 2023 – the era of rapid price drops is over. STC rebates shrink every year until the scheme ends in 2030. Feed-in tariffs are dropping. Waiting almost always makes payback worse, not better.
How do I compare solar quotes?
The three things that matter: panel brand (tier 1 – LG, REC, Longi, Jinko, Trina), inverter brand (Fronius, SMA, Sungrow, Enphase), and installer warranty (10+ years workmanship, not just manufacturer warranty passed through). Whole-of-system price alone means nothing without those three.
→ Paste your solar quotes into our comparator to spot missing warranty terms, ambiguous inverter models, and unusually short payment terms.
Are cheap Chinese panels safe?
The tier-1 vs tier-3 divide isn’t country of origin – almost all panels are Chinese-manufactured. Tier-1 means the manufacturer has been bank-financed for 5+ years (a proxy for “will still exist to honour warranty”). LG (tier-1) and no-name tier-3 both come from similar factory locations – the difference is corporate stability, not build quality per se.
What if I’m renting or planning to sell within a few years?
Payback of 4-5 years means selling before then loses money on the panels but you may recover partial value in the sale price – Australian data suggests solar adds around 3-4% to property value. If you plan to sell in year 6+, the maths usually still works.
Related tools
- Battery Payback Calculator – should you add a battery to your solar?
- Renovation Quote Comparator – paste your solar quotes for red-flag analysis
- Electrician Cost Australia – what to expect for the electrical side
- Renovation Budget Tracker – track spend against category budgets
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