Solar Savings & Payback Calculator
Estimate simple solar payback using installed cost, incentives, annual production and the value of each kWh.
Solar Savings & Payback Calculator
*Simplified: assumes constant electricity value and excludes financing, maintenance, taxes, export-credit rules and inverter/battery replacement.
Simple solar payback
Simple payback = Net upfront cost ÷ First-year annual savings
A rigorous financial model should also include financing, tax treatment, electricity price escalation, panel degradation, inverter replacement, maintenance, export compensation and the household's self-consumption profile.
Frequently asked questions
Is simple payback the same as ROI?
No. Simple payback tells you how long it takes cumulative savings to recover upfront cost; ROI measures return relative to investment over a chosen period.
Should I use the retail electricity rate?
Only for energy that offsets retail purchases. Exported solar may be compensated at a different rate depending on local rules.
Estimates only. Actual energy use and costs vary by equipment, climate, tariffs, installation conditions and user behavior.