Solar payback calculator
Explore undiscounted solar electricity value and payback from your generation, self-consumption, import/export prices, degradation and tariff-change assumptions.
Installed cost 0 to 1 trillion in one currency; first-year generation 0 to 1 billion kWh; self-consumption 0 to 100%; prices explicitly entered from 0 to 100,000 per kWh. Degradation 0 to 99%; annual price change -99 to 100%; horizon 1 to 100 whole years. Extreme combinations outside the shared finite-output limit are rejected. JSON report, results CSV and full year-zero-through-horizon cash-flow CSV. Enter installation cost, generation, prices and scenario assumptions in the settings. No text input is needed. Up to 1,000,000 characters. Review the settings before running.
Your result
How to use Solar payback calculator
- Enter installed cost and estimated first-year generation.
- Enter the self-consumption share and your import and export prices; use an explicit 0 for a price you exclude.
- Choose annual degradation, a common import/export price-change assumption and the horizon.
- Review year-zero outlay, annual value, cumulative cash flow and nullable payback, then export JSON and CSV.
Useful next steps
Value of generated electricity
Self-consumed generation avoids your marginal import energy price. The remainder earns the export payment you enter. Standing charges are not automatically avoided. Prices use one currency, with no tariff, subsidy or tax database.
A scenario, not a financial promise
Degradation and price changes compound from year two. The self-consumption share remains fixed, and both import and export prices use the same escalation rate. Costs for finance, maintenance, replacements and tax are excluded; cash flows are not discounted.
Two payback measures
Simple payback divides installation cost by positive first-year electricity value. Cumulative payback finds the first cost crossing in the horizon and interpolates evenly within that year. No crossing is reported as not defined. Zero installation cost has payback zero. The year-zero row records the installation outflow; display rounding occurs after calculations.