Solar ROI calculator
Check your solar payback — enter net system cost and monthly savings, get payback years, 25-year cumulative savings and profit.
Quick answer: A $12,000 net system saving $150/month pays back in 6.7 years. With 3% annual price growth, 25-year cumulative savings reach $65,627 — about $53,627 of net profit after the system is paid off.
Investment details
| Year | Cumulative savings |
|---|---|
| 5 | |
| 10 | |
| 15 | |
| 20 | |
| 25 |
Ballpark, not gospel. Simple payback ignores panel degradation (~0.5%/yr) and one inverter replacement — treat the 25-year figure as an upper bound.
How $1,800/year of savings compounds at 3% growth
| Year | Cumulative savings | What's happening |
|---|---|---|
| 5 | $9,556 | Approaching payback on a $12,000 system |
| 10 | $20,635 | Pure profit territory begins |
| 15 | $33,478 | Budget an inverter replacement around here |
| 20 | $48,367 | Savings now exceed 4× the system cost |
| 25 | $65,627 | End of panel warranty — still generating ~88% |
Price escalation back-loads earnings: year 1 saves $1,800, but year 25 saves about $3,660. Switch currency above for your market.
Solar payback calculator
This page is a solar payback calculator: system cost divided by annual bill savings, with electricity price growth compounding the savings every year. The default $12,000 / $150-mo example pays back in 6.7 years — high-rate markets like the UK or Australia pay back faster, which is why the currency switcher above matters.
Solar savings calculator
It is also a solar savings calculator: the milestone table tracks cumulative savings at years 5, 10, 15, 20 and 25, and "Net profit" subtracts what you paid. At 3% annual price growth, $1,800/year of bill savings becomes $65,627 over 25 years.
Questions people actually ask
Straight answers, no fluff. Then run your own numbers above.
How do you calculate solar payback?
Divide net system cost by annual bill savings. A $12,000 net system saving $150/month ($1,800/year) pays back in 6.7 years. The calculator then compounds savings at your electricity price growth rate for the 25-year picture.
What are the 25-year savings on a typical US system?
With $1,800 a year of first-year savings and 3% annual price growth, cumulative 25-year savings reach about $65,627 — a net profit near $53,627 on a $12,000 net system.
Does electricity price growth really matter that much?
Yes — it back-loads the earnings. Year 1 saves $1,800 but year 25 saves about $3,660, so the second half of a panel's life produces most of the profit. The milestone table above shows it year by year.
What is a good solar payback period?
Under 8 years is strong in high-rate markets, 8–12 years is typical in the US and UK, and anything under the 25-year panel warranty is still technically profitable — shorter is just better.
Should I include panel degradation in ROI?
Panels lose ~0.5% output a year — over 25 years that shaves a few percent off lifetime savings. The calculator's simple compounding is slightly optimistic; treat it as an upper bound.
Does ROI include the inverter replacement?
The simple version here does not. Budget one inverter replacement around year 12–15 — a few thousand dollars — against the lifetime profit.
Is solar still worth it if I might move house?
Often yes: studies consistently show owned solar adds resale value close to its remaining payback value. Just confirm the system is fully owned, not leased.
How does financing change the payback math?
Loans stretch payback by the interest paid — a $12,000 system at typical solar-loan rates can cost $15,000–$18,000 all-in. Enter the total financed cost as the system cost above.
What is a solar payback calculator?
A tool that divides your net system cost by annual bill savings to find the break-even year, then compounds savings at electricity price growth for the lifetime picture. This page is one — the default example pays back in 6.7 years.
What does a solar savings calculator include?
Year-by-year cumulative savings with price escalation, total 25-year savings, and net profit after subtracting system cost. The milestone table above shows all three at years 5, 10, 15, 20 and 25.
Need the net cost first? The solar cost calculator prices any system size after credits. Sizing the array? The country calculators size panels from your bill, and the solar system calculator handles batteries and inverters.