Solar Panel Savings Calculator
Estimate annual bill savings and the payback period for a rooftop solar system based on system size, self-consumption rate and feed-in tariff.
Varies by location, orientation, shading and season — 4.0 is a common illustrative average.
Portion of solar used at home rather than exported.
Illustrative default — your plan's rate varies by retailer and state.
Illustrative default — feed-in rates vary by retailer, state and time.
Your results
Actual prices, usage, efficiency and savings vary by provider, equipment, location and behaviour.
Calculation breakdown
- Annual production
- 6.6 kW × 4 kWh/kW/day × 365 = 9,636 kWh
- Total annual benefit
- $1,156.32 self-consumption + $346.90 export credits = $1,503.22
- Simple payback
- $6,500.00 ÷ $1,503.22/yr = 4.3 years
Assumptions
- Daily production per kW is an illustrative estimate — real output depends on your location, roof orientation, shading and time of year.
- Electricity and feed-in tariffs are user-entered illustrative defaults, not official or retailer-guaranteed rates.
- Panel degradation is applied evenly across the projection period; real degradation curves vary by manufacturer.
- Simple payback ignores financing costs, inflation and any rebates already reflected in your install cost.
How this calculator works
Enter your system size in kilowatts, local sun hours, how much generation you use in the home, your electricity rate and feed-in tariff. The calculator estimates annual generation, savings from self-consumption, feed-in credits and the simple payback period on the installed price.
Frequently asked questions
How many sun hours should I use?
Australian capitals typically average between 3.5 and 4.5 peak sun hours per day, with northern cities at the higher end.
Why does self-consumption matter so much?
Power you use yourself avoids the full retail rate, while exported power only earns the much lower feed-in tariff.
Is the rebate included?
Enter the price after any small-scale technology certificate discount, which most installers already apply to their quoted price.
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.