Solar Payback & ROI Calculator
Find out when your PV system pays off, with break-even time and expected return on investment, entirely local and private. Runs in your browser, GDPR-compliant.
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Legal notice
Current as of: 11.08.2026.
The results reflect the legal and fiscal state as of the date stated above. They are provided for general information and initial guidance only. They are not individual financial, tax or legal advice, and no guarantee is given as to their accuracy, completeness or suitability for your circumstances. In particular, the results are not a substitute for an official or judicial assessment. Please check the information independently and seek qualified advice where appropriate, as you are solely responsible for any decision made in reliance on the result.
How to use this tool (video)
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Solar payback calculator: when your system pays off
When will I get my money back from a photovoltaic system? The answer depends above all on one number: how much of the power you produce you actually use yourself. Our payback calculator determines the break-even period of your PV investment over 25 years, accounting for your savings from self-consumption, income from grid feed-in, an assumed electricity price escalation, annual maintenance and the gradual degradation of the modules. So you see not just what the system costs but what it really returns over its lifetime.
How the calculator works
Every year the system generates electricity that splits into two parts. The self-consumed share replaces expensive grid power and is valued at the full household electricity price, in Germany currently averaging about 37 cents per kilowatt hour, between 35 and 40 cents depending on the tariff. The surplus power is fed into the grid and paid at the feed-in tariff, which is locked in for 20 years after commissioning and in 2026 sits at about 7.7 cents per kilowatt hour for small systems up to 10 kWp (partial feed-in). That gap between the power price and the feed-in tariff is exactly why self-consumption is the most important lever. The calculator deducts annual maintenance from both income shares. Break-even is reached once the cumulative benefits exceed the initial investment.
What the payback period tells you
The payback period is the point at which your savings and feed-in payments have covered the purchase cost. For modern German systems it usually lands between 8 and 15 years depending on location, orientation and self-consumption, and in favourable cases below that. Afterwards the system keeps earning, typically a return in the single-digit percentage range per year. The calculator also shows your cumulative benefit after 5, 10, 15, 20 and 25 years plus the total profit after 25 years.
Sample calculation
An 8 kWp system costing 9,600 euros produces around 8,000 kWh per year in Germany depending on the location. With a power price of 37 cents, 40 percent self-consumption, a 7.7 cent feed-in tariff and 100 euros of maintenance per year, the year-one benefit is about 1,450 euros. Assuming 3 percent annual price escalation, the system pays back after about 6 years and yields a clear profit over 25 years.
Frequently asked questions
What is the 2026 German feed-in tariff?
The statutory feed-in tariff is set by the German Federal Network Agency and decreases slightly with each registration. As of August 2026 it sits at about 7.7 cents per kWh for small systems up to 10 kWp (partial feed-in). This value is a good starting point and the calculator uses the value you enter. For the current binding tariff, check the Bundesnetzagentur website.
How high should the self-consumption share be?
The higher the better for profitability, because self-consumed power saves the full household electricity price. For a typical family system it is 30 to 50 percent, often higher with a battery. You can adjust the value directly in the calculator.
What is the payback period?
It shows after how many years your cumulative savings and feed-in payments cover the investment costs. Only then does the system make a profit in accounting terms. The calculator determines it year by year with all assumptions.
Why does the calculator use an electricity price escalation?
The German power price has historically risen. Because self-consumed power saves this rising price, your benefit grows over the years. The 3 percent per year default is adjustable; try 0 percent for a conservative view.
Is this a binding return calculation?
No. It is a transparent estimate based on your assumptions. Yield, price development, shading and maintenance are uncertain. The calculator is not a substitute for advice or tax advice. For binding planning, commission an energy advisor or installer.
Are my data stored?
No. All calculations run 100 % locally in your browser. Your entries are neither sent to a server nor stored.
Read more about this tool
How the calculator works in detail
The calculator works year by year in transparent steps. First it estimates your annual yield in kilowatt hours from the system size, typically around 800 to 1,000 kilowatt hours per kilowatt-peak per year in Germany. It then splits that yield into two streams according to your self-consumption share: power you use yourself, valued at your household power price, and power you feed in, paid at your tariff. Both figures run over 25 years. The power price rises each year by your assumed escalation, while the yield slowly declines with module degradation of about 0.4 percent per year. Each year maintenance is deducted. At the end the calculator finds the first year in which the sum of all benefits exceeds the initial investment and reports it as the payback period.
An example of how this works: with a benefit of about 1,450 euros in the first year and a purchase price of 9,600 euros, the system reaches the point where it has paid for itself after about six years and keeps earning from then on.
Why self-consumption decides your return
Today the decisive lever is self-consumption, not the feed-in tariff. A kilowatt hour you use yourself saves you the full household power price of often 35 to 40 cents, while feeding in brings only about 7.7 cents in 2026. Self-used power is worth roughly five times as much as power you feed in. Typical households without a battery reach a self-consumption share of 30 to 40 percent, and with a well-sized battery often 60 to 80 percent. That makes it more worthwhile to shift high-power devices such as a washing machine or heat pump into the middle of the day, or to plan a battery, than to chase a few extra cents of tariff.
Costs, taxes and realistic figures
A realistic frame of reference helps with the numbers. Turnkey systems in Germany currently cost roughly 1,400 to 1,800 euros per kilowatt-peak net, with smaller systems tending to cost more per kilowatt-peak than larger ones. Since 2023 the delivery and installation of photovoltaic systems and batteries has been exempt from value added tax, and this can already be reflected in the price. You can find the inputs for the calculator in your own documents: the power price on your annual bill and the current feed-in tariff from the Federal Network Agency. A realistic self-consumption share has the biggest influence on the result.
Does the calculation really run locally?
Yes. All calculations run 100 % in your browser, with no server and no account. Your entries are neither transmitted nor stored. You can vary assumptions freely and compare scenarios safely, your data stays on your device.