Solar savings and payback calculator
Enter your consumption and roof, and see production, annual benefit and payback. Every constant used is listed with its source below the result.
Data set
These are reference values for Europe. Our country sites carry verified local data: myosolar.de, myosolar.at, myosolar.ch, myosolar.it, myosolar.es, myosolar.fr
Your inputs
kWh
kWp
A battery raises self-consumption and the investment at the same time.
PVGIS was not reachable, so this result uses the market average yield and is an estimate rather than a location specific calculation.
Result
after that, around 17 years of practically free electricity
around 24.1 kWh on an average day
covers around 58.7% of your electricity demand
that is €102 less on the electricity bill every month
Average per year over 25 years, including the assumed electricity price increase.
VAT is not included in this figure, because the rate is set nationally and ranges from 0 percent to 27 percent across Europe. Select your country to see the rate that applies.
Cumulative savings over 25 years
Text summary of the chart: Cumulative benefit €34,244 (25 year)
Show the result as a table
| Year | Cumulative benefit |
|---|---|
| 5 | €5,807 |
| 10 | €12,096 |
| 15 | €18,905 |
| 20 | €26,274 |
| 25 | €34,244 |
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Assumptions and sources
The market data behind the calculation above, with source, date and quality, followed by the modelling assumptions the result depends on.
Change our assumptions
These are estimates for your market. Enter your real rates and every result recalculates immediately.
Market data with sources
- Household electricity price0.2896 EUR/kWh
European reference value. Choose your country site for local figures.
- Feed-in remuneration0.08 EUR/kWh
Illustrative only. Never print in an article. Use the market specific constant instead.
- Specific yield1,100 kWh/kWp
Illustrative only. Never print in an article. Use the market specific constant instead.
- System cost per kWp, lower end900 EUR/kWpreference valueFraunhofer ISE Photovoltaics Report, German rooftop 10 kWp, used as the European reference2026-07-14
German price level used as a European reference.
- System cost per kWp, upper end1,500 EUR/kWpreference valueFraunhofer ISE Photovoltaics Report, German rooftop 10 kWp, used as the European reference2026-07-14
German figure used as a European reference. Verified national ranges in August 2026 are materially wider: AT 1800 to 2500 EUR/kWp, ES 800 to 1400 EUR/kWp, CH 2400 to 3200 CHF/kWp, IT 1300 to 3500 EUR/kWp.
- Battery cost per kWh, lower end400 EUR/kWh
- Battery cost per kWh, upper end900 EUR/kWh
Modelling assumptions
These are modelling choices, not measurements. They shape the result, so we name each one and what it does to it.
- Self-consumption share12 to 90 percent, derived
We derive the share of your production that you use yourself from the ratio of annual production to annual consumption: the larger the system compared with your demand, the smaller the share. A battery raises it, in proportion to how much of a day of consumption it can store. A higher share raises the saving, because power used at home avoids the full electricity price.
- Annual operating cost1% of the investment
Insurance, metering, cleaning and repairs. Subtracted from the benefit every year, so it moves the payback date later.
- Module degradation0.5% per year
Panels lose a little output each year, so the annual benefit falls slowly across the projection.
- Electricity price increase2% per year
Assumed rise in the price of grid electricity. Every kilowatt-hour used at home is worth more over time, which shortens the payback.
- Projection horizon25 years
Cash flows are added up over this many years. Nothing beyond it is counted.
Rules that apply in your market
- These figures are European reference values, not the rules of a single country. Our country sites carry verified local data.
Frequently asked questions
- How reliable is a payback figure?
- It depends mostly on the electricity price and on how much of your production you use yourself. We show both values, so you can judge how sensitive the result is.
- Are subsidies included?
- Capital subsidies are included where they exist as a fixed rate per kWp, for example the Swiss one off payment. Tax deductions are shown as a note because they depend on your personal situation.
- Why does my installer quote a different figure?
- Quotes use site specific yield, shading and component choice. Our model uses verified market averages, so treat the result as a range rather than a promise.
Related tools
- Solar cost calculatorCost range with a component breakdown, plus a check whether an offer is fair.
- Solar yield calculatorAnnual and monthly production for your location, orientation and tilt.
- Self-consumption and battery size calculatorSelf-consumption with and without a battery, plus the size that pays back.
Matching guides
This is a transparent model for orientation, not an offer, not a yield guarantee and not financial advice. Binding figures need a site survey.