- Solar ROI Calculator
Solar ROI Calculator
Use our free solar ROI calculator to estimate your return on investment, solar payback period, and long-term electricity savings. Compare installation costs, energy production, and electricity rates to understand your potential solar investment.
- Free to use
- 25-Year Forecast
- Instant estimate
Solar project details
25-year forecastSolar investment results
Estimated outcomeTotal modeled net savings minus net upfront cost
25-year net cash-flow forecast
Cumulative modeled electricity savings, less maintenance and the initial investment. The horizontal line marks break-even.
Year-by-year savings and payback
Review annual net savings, cumulative net savings and balance after the upfront cost.
| Year | Net annual savings | Cumulative savings | Net cash flow | Status |
|---|
How to Use the Calculator
Estimate your solar investment returns in three simple steps.
STEP 01
Enter Project Details
Enter your solar installation cost, system capacity, and average monthly electricity bill. Use actual project quotes when available. These details help establish your upfront investment and estimated annual energy production.
STEP 02
Adjust Financial Assumptions
Set your electricity value, expected energy-price growth, and applicable incentives. You can also adjust solar yield, panel degradation, and maintenance costs to compare different long-term scenarios.
STEP 03
Review Your Solar Returns
Check your projected ROI, first-year savings, and simple payback period. Review the 25-year cash-flow chart to see when cumulative savings may recover your initial investment.
Understanding Your Results
Learn what each solar investment result means before making financial decisions.
25-Year Net Benefit
Shows total modeled net electricity savings over 25 years after subtracting your upfront solar investment. Positive results indicate projected gains under the selected assumptions, not guaranteed profit.
Net Upfront Cost
Displays your estimated solar installation expense after subtracting the selected percentage-based incentive. Include eligible equipment and installation costs when entering your original project budget.
Simple Payback Period
Estimates how long first-year net savings would take to recover your investment if they remained constant. It does not include future electricity-price increases.
25-Year Solar ROI
Shows the percentage return on your initial investment using projected 25-year net benefits. It is a simple, undiscounted ROI estimate, not an annual investment return.
Break-Even Year
Identifies the first modeled year when accumulated net savings equal or exceed your upfront solar investment. Unlike simple payback, this forecast accounts for electricity-price growth, panel-output decline, and your annual maintenance allowance. The calculator also displays first-year savings and annual solar generation, helping you understand the assumptions behind your estimated break-even point.
How Solar ROI Is Calculated
Solar return on investment compares your initial project cost with the estimated electricity savings generated over time.
The calculator models annual solar production, electricity value, applicable incentives, panel degradation, and maintenance expenses.
Solar ROI Formula
Net Investment = Installation Cost × (1 − Incentive Rate)
First-Year Electricity Savings = Lower of (Annual Electricity Bill) or (Annual Solar Production × Electricity Value)
Annual maintenance is deducted when calculating net savings.
25-Year ROI (%) = (25-Year Net Savings − Net Investment) ÷ Net Investment × 100
Practical Solar ROI Example
Suppose you install a 7 kW solar system costing $18,000.
With the calculator’s default assumptions:
Annual solar generation: 9,800 kWh
Electricity value: $0.15/kWh
First-year savings: $1,470
Electricity-price growth: 3% annually
Panel-output decline: 0.5% annually
Incentives and maintenance: $0
Estimated simple payback: 12.2 years
Estimated 25-year ROI: 178.4%
Estimated break-even: Year 11
The break-even year differs from simple payback because projected energy savings increase over time in this example.
Installation Cost: Higher upfront costs can extend your solar payback period. Compare complete solar quotes, including panels, inverter, mounting equipment, and installation expenses, before calculating returns.
Electricity Rates: Higher electricity value can increase the financial benefit of solar generation. Actual savings depend on household self-consumption, export compensation, utility rates, and billing rules.
Solar Energy Production: Annual photovoltaic output depends on system size, sunlight, panel orientation, shading, and equipment efficiency. Use location-specific production estimates when available for better financial planning.
Maintenance and Degradation: Solar panels gradually lose some output over time. Maintenance costs, inverter replacement, and other expenses may reduce long-term returns. Review these factors before relying on an ROI forecast.
Solar Investment: From Cost to Savings
Follow the main stages used to estimate solar payback.
1. Initial Investment
Enter your complete installed solar system cost.
2. Solar Generation
Estimate annual electricity produced by your panels.
3. Electricity Savings
Calculate the est. value of generated electricity.
4. Cost Recovery
Compare savings against your investment.
5. Long-Term Returns
Review projected net benefits over 25 years.
Frequently Asked Questions
How do you calculate solar ROI?
Subtract your initial net investment from projected total net savings. Divide the result by your net investment and multiply by 100. This calculator estimates returns over 25 years.
What is a good ROI for solar panels?
A good solar ROI depends on installation costs, local electricity prices, solar production, maintenance, and alternative investments. Compare different scenarios rather than relying on a single percentage.
How long does it take solar panels to pay for themselves?
Solar payback varies by project. Divide your net installation cost by first-year net savings for a simple estimate. The modeled break-even year may differ because future energy prices and system performance can change.
How much money can solar panels save each year?
Savings depend on annual solar production and the value of electricity generated. This calculator estimates first-year savings using energy output and electricity value, limited by your current annual electricity bill.
Is the 30% US federal solar tax credit available in 2026?
For new residential installations completed after December 31, 2025, the former federal Section 25D credit is no longer available. Other incentive programs may have different eligibility rules. See the IRS guidance.
Does this calculator include solar panel degradation?
Yes. The advanced settings include an annual output-decline assumption. You can also enter annual maintenance costs. The calculator does not separately model financing interest, major equipment replacements, or discounted cash flow.
How can I make my solar ROI estimate more accurate?
Use actual installation quotes, electricity bills, and local utility rates. For a more reliable solar production estimate, compare your assumptions with the PVWatts Calculator, then adjust the annual solar yield accordingly.
Related Solar Calculators
Explore these free tools to plan your solar energy system with more detailed estimates.
Estimate solar installation costs, equipment expenses, and monthly electricity savings before evaluating your investment return.
Estimate daily, monthly, and annual solar panel energy output to improve your solar ROI calculations.
Estimate battery storage capacity and backup requirements before including energy storage in your solar project budget.
Important: Solar ROI results are illustrative financial projections, not guaranteed investment returns. Actual outcomes depend on electricity rates, utility export policies, solar production, incentives, maintenance, financing, and equipment performance.