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Solar Savings Calculator
See exactly how much solar could save you. Enter your quarterly electricity bill, pick your state, choose a system size — and watch your 25-year savings projection update in real time. All calculations use current 2026 Australian electricity rates, sun hours, and rebate data.
UPDATED MARCH 2026 · RATES FROM AER & CER · INCLUDES 5% ANNUAL PRICE RISE ASSUMPTION
How the Solar Savings Calculator Works
Our calculator uses real Australian energy data to model your solar investment over 25 years — the typical warranty period for quality solar panels. Unlike simple "payback calculators" that only give you a single number, this tool models year-by-year savings with compounding electricity price increases, panel degradation, and the split between self-consumed power and grid exports.
The three inputs that matter most are your electricity bill (which tells us how much energy you use), your state (which determines sun hours, electricity rates, and feed-in tariffs), and your system size (which determines how much power you generate). From these, we calculate daily production, annual savings, cumulative returns, and your payback period — all in real time as you adjust the sliders.
What Affects Your Solar Savings?
Several factors determine how much you'll actually save. Electricity rates are the biggest driver — South Australia's high rates (36c/kWh+) mean faster payback compared to Tasmania (26c/kWh). Sun hours matter too: Darwin and Perth average over 5.4 peak sun hours daily, while Hobart sees around 3.6. Self-consumption is critical — every kilowatt-hour you use directly saves you the full retail rate, while exported energy only earns 5–8c/kWh in most states. This is why we model 55% self-consumption as a realistic baseline for households that are home during parts of the day.
We also factor in two often-overlooked variables. First, electricity price increases — Australian electricity has risen an average of 5% per year over the past decade, which means your solar savings grow over time even as your panels slowly degrade. Second, panel degradation at 0.5% per year means a 6.6kW system produces roughly 6.3kW-equivalent in year 25. Both factors are baked into every projection above.
Tips to Maximise Your Solar Savings
The single biggest lever is self-consumption. Shift energy-hungry appliances — dishwashers, washing machines, pool pumps, hot water — to run during daylight hours. Even moving from 40% to 60% self-consumption can add $300–$500/year to your savings. If you work from home, you'll naturally self-consume more, which improves your return.
Choosing the right system size matters too. Oversizing slightly (getting a 6.6kW instead of 5kW, for example) often makes sense because the marginal cost per kilowatt decreases with larger systems, and you future-proof against increasing consumption from EVs or home batteries. Speaking of batteries — adding one later with a hybrid inverter lets you store daytime excess for evening use, pushing self-consumption above 80% and dramatically cutting grid reliance.
Solar Savings by State
South Australia typically delivers the fastest payback thanks to the nation's highest electricity rates, despite mid-range sun hours. Queensland and Western Australia benefit from excellent sunshine (5.2–5.4 peak hours), while Victoria's Solar Homes rebate of $1,400 significantly reduces upfront costs. The ACT offers generous interest-free loans up to $15,000 through the Sustainable Household Scheme, and the Northern Territory's combination of Zone 1 STCs and the highest sun hours in Australia (5.8 peak hours) makes it surprisingly attractive.
| State | Sun Hours | Elec Rate | Feed-in | Avg Cost (6.6kW) |
|---|---|---|---|---|
| QLD | 5.2h/day | 28c/kWh | 5.0c/kWh | $5,500 |
| NSW | 4.6h/day | 30c/kWh | 5.0c/kWh | $5,500 |
| VIC | 4h/day | 27c/kWh | 4.5c/kWh | $4,100 |
| SA | 5h/day | 36c/kWh | 5.0c/kWh | $5,500 |
| WA | 5.4h/day | 31c/kWh | 2.5c/kWh | $5,500 |
| TAS | 3.6h/day | 26c/kWh | 6.0c/kWh | $5,500 |
| NT | 5.8h/day | 27c/kWh | 8.4c/kWh | $5,500 |
| ACT | 4.5h/day | 25c/kWh | 6.5c/kWh | $5,500 |
Frequently Asked Questions
How accurate is this solar savings calculator?
Our calculator provides a strong estimate based on real Australian data — state sun hours from the BOM, electricity rates from the AER, and system costs from industry sources. Actual results vary based on roof orientation, shading, specific tariff plans, and consumption patterns. For a more precise figure, use our Solar Score tool which factors in your postcode and roof details.
Why do savings increase each year?
We model a 5% annual electricity price increase, which aligns with the historical Australian average over the past decade. As grid electricity gets more expensive, the value of every kilowatt-hour your panels produce goes up — so year-10 savings are significantly higher than year-1 savings, even accounting for minor panel degradation.
Should I include a battery in my calculation?
This calculator estimates savings for a solar-only system. Adding a battery can increase self-consumption from ~55% to 80%+ but adds $7,000–$13,000 to costs. Batteries are most worthwhile if you have time-of-use tariffs, need backup power, or want maximum grid independence. Check our Battery Guide for a detailed cost-benefit analysis.
What does "self-consumption" mean?
Self-consumption is the percentage of solar energy you use directly in your home (rather than exporting to the grid). Higher self-consumption means bigger savings because you avoid buying electricity at 25–36c/kWh. We use 55% as a realistic baseline — you can improve this by running appliances during daylight hours.
Is the payback period really that short?
For most Australian homes, yes. A 6.6kW system costing $4,000–$5,500 after rebates and saving $1,500–$2,500 per year genuinely pays for itself in 3–5 years. After that, your electricity savings are essentially free money for the remaining 20+ years of panel life.