Solar Payback Calculator
Estimate the payback period and long-term savings of a rooftop solar system in Australia after rebates, feed-in tariffs and annual panel degradation.
Your results
| Years | Cumulative saving |
|---|---|
| 10 | $11,882.48 |
| 20 | $23,135.14 |
| 25 | $28,534.97 |
Calculation breakdown
- Net system cost
- $9,000.00 − $0.00 = $9,000.00
- Annual benefit
- (2,975 kWh × $0.35/kWh) + (5,525 kWh × $0.05/kWh) − $100.00 = $1,217.50
- Payback period
- Years until cumulative annual benefits (adjusted for panel degradation) equal the net system cost.
Assumptions
- Future electricity prices, feed-in tariffs and your household usage pattern are not guaranteed to stay the same.
- Solar panel output is assumed to degrade steadily each year at the rate entered.
- Self-consumption percentage is assumed constant across the analysis period.
- Maintenance costs are assumed constant in nominal dollars each year.
How this calculator works
Solar saves you the import tariff on energy you use yourself and earns the feed-in tariff on what you export. This calculator combines both, subtracts maintenance, applies annual panel degradation and finds the year your net system cost is recovered.
Frequently asked questions
What self-consumption rate is realistic?
Typically 20–40% without a battery, and considerably higher if you shift usage into daylight hours or add storage.
Are rebates included?
Enter your rebate or discount as an amount. Federal STC discounts are usually already deducted from quoted prices.
How long do panels last?
Most carry a 25-year performance warranty with a roughly 0.5% annual degradation rate.
Actual prices, usage, efficiency and savings vary by provider, equipment, location and behaviour.
Results are estimates only and are not financial, tax, legal or credit advice.