How to use the Solar Payback Period (ROI) Calculator
The Formula
Net cost = system cost × (1 − incentive %). Annual savings = annual kWh × $/kWh. Payback years = net cost ÷ annual savings.
Practical Example
We also show rough 25-year net savings (no rate escalation or degradation). Use Solar Degradation or the 20-Year Degradation ROI tool for long-term output and payback.
About Solar Payback Period (ROI) Calculator
Payback formula
Net cost = system cost × (1 − incentive %). Annual savings = annual kWh × $/kWh. Payback years = net cost ÷ annual savings.
ROI note
We also show rough 25-year net savings (no rate escalation or degradation). Use Solar Degradation or the 20-Year Degradation ROI tool for long-term output and payback.
Frequently asked questions
Q: Does this include financing? A: No—cash purchase only. Q: Are incentives guaranteed? A: Check local programs; this is a planning estimate.