Solar ROI & Payback Calculator
Calculate solar panel payback period and return on investment. Instantly see annual savings, net system cost after incentives, and simple payback years.
How It Works
Estimates the payback period and total savings of installing solar panels. It compares the upfront cost (minus tax credits) against the projected annual electricity savings.
Formula
Payback Period (Years) = Net System Cost / Annual Electricity Savings
Net System Cost = Total Cost - Government Tax Incentives
Electricity savings are calculated by taking the percentage of your bill offset by solar, multiplied by your annual electricity spend.
Worked Example
Calculating a 5kW Solar System Payback
- Gross System Cost: $15,000
- Federal Tax Credit (30%): -$4,500
- Net Cost: $10,500
- Current Monthly Electric Bill: $150 ($1,800/yr)
- Solar offsets 100% of bill: Saves $1,800/yr
- Payback Period = $10,500 / $1,800 = 5.8 years.
Common Mistakes
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Assuming the tax credit is a refund
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The federal ITC is a non-refundable tax credit. It reduces the tax you owe. If you owe $0 in taxes, you cannot claim the credit (though it can roll over).
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Forgetting panel degradation
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Solar panels lose about 0.5% efficiency per year. Over 25 years, they will produce slightly less power than in year one.
Frequently Asked Questions
Related Guide & Instructions
2026-07-06
Is Solar Worth It? How to Calculate Solar Panel ROI and Payback Period
Discover if solar panels make financial sense for your home, how to calculate payback years, and estimate long-term savings.
Read full guide →Related Calculators
DisclaimerThe results provided by this calculator are estimates and for informational purposes only. They do not constitute financial, legal, or professional advice. Please consult with a qualified professional for your specific needs.