When does solar pay for itself?
The page opens on a worked example: a 6 kWp rooftop system with typical European figures. Change the cost, your tariff or how much of the power you use at home, and the payback year moves with it.
The answer
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Year by year
| Year | Output (kWh) | Savings | Running total |
|---|
Nothing to calculate yet
Enter your system cost, electricity price, yield and the share you use at home.
Questions
Simple payback is the year in which the money the panels have saved you adds up to what the system cost.
Each year counts the electricity you no longer buy at the import price, plus what you are paid for the rest at the export price. The page adds those years up and stops where the running total crosses zero - the marked point on the chart.
It does not discount future money, so it reads a little shorter than an investor's figure.
Financing cost, taxes, subsidies and batteries. Feed-in schemes count only as the flat export price you enter, and inverter replacement and maintenance are left out.
A loan, a grant or a battery changes the answer, sometimes by years, so treat the figure as the system on its own, paid in cash.
The panel price is the median shop price per watt for modules in the largest market quoting in your currency, from the offers we track; the note under the field names the market and the number of offers. It covers the modules only, not an installed system.
The yield is the pitched-roof baseline our panel comparison calculator uses, and the annual degradation is the median of the modules in our catalogue that state one.
Other costs (inverter, mounting, labour), electricity prices, self-consumption and price growth are assumptions for a European home without a battery, marked as such beside each field. Replace them with your quote and your tariff.