The solar payback period is how long it takes for your electricity-bill savings to cover the cost of the system. In Australia in 2026, a typical 6.6 kW system pays back in 3 to 5 years, among the fastest in the world, thanks to high power prices and the federal rebate.
How to calculate solar payback
Payback (years) = net system cost ÷ annual bill savings
Example: a 6.6 kW system at $5,500 net, saving $1,400 a year → a 3.9-year payback. After that, the savings are yours for another 20+ years.
What changes your payback
- Daytime self-consumption, the biggest lever. Power you use yourself avoids the full ~30c/kWh import rate; exported power earns only the feed-in tariff (4–10c).
- Your state's rebates, VIC, NSW, WA and ACT stacks shorten payback; see your state rebate page.
- System size vs your bill, an oversized system with low self-consumption pays back more slowly.
What about battery payback?
Batteries take longer, typically 5–8 years in states that stack the federal + state battery rebate, and 8–11 years elsewhere. Joining a Virtual Power Plant shortens it. Run your numbers for an estimate.
Common questions
What is a good solar payback period?
In Australia, anything under 5 years is good and very common for panels. Under 4 years is excellent and typical in high-rebate states like Victoria.
How is solar payback calculated?
Net system cost (after rebates) divided by your annual electricity-bill savings. A $5,500 system saving $1,400/year pays back in about 3.9 years.
Why is my solar payback longer than 5 years?
Usually low daytime self-consumption (you export most of your solar for a small feed-in tariff), an oversized system, or a shaded/poor-orientation roof. Shifting usage to daytime or adding a battery improves it.