Solar Panel ROI Calculator
Calculate whether solar panels are worth it for your home. Model the 30% federal tax credit, state incentives, payback period, 25-year savings with rate escalation, financing options, net metering, and battery storage.
| Year | Rate/kWh | Annual Savings | Maintenance | Net Savings | Cumulative |
|---|---|---|---|---|---|
| 1 | $0.150 | $1,500 | $300 | $1,200 | $1,200 |
| 6 | $0.178 | $1,737 | $300 | $1,437 | $7,898 |
| 11 | $0.212 | $2,012 | $300 | $1,712 | $15,894 |
| 16 | $0.251 | $2,331 | $300 | $2,031 | $23,394 |
| 21 | $0.298 | $2,700 | $300 | $2,400 | $34,634 |
| 25 | $0.342 | $3,037 | $300 | $2,737 | $45,063 |
Complete 25-year financial model including panel degradation, maintenance, and inverter replacement.
| Year | Savings | Rate/kWh | Costs | Net | Cumulative Return |
|---|---|---|---|---|---|
| 1 | $1,500 | $0.150 | $300 | $1,200 | -$14,300 |
| 2 | $1,545 | $0.155 | $300 | $1,245 | -$13,055 |
| 3 | $1,591 | $0.161 | $300 | $1,291 | -$11,764 |
| 4 | $1,638 | $0.166 | $300 | $1,338 | -$10,426 |
| 5 | $1,687 | $0.172 | $300 | $1,387 | -$9,039 |
| 6 | $1,737 | $0.178 | $300 | $1,437 | -$7,602 |
| 7 | $1,789 | $0.184 | $300 | $1,489 | -$6,112 |
| 8 | $1,843 | $0.191 | $300 | $1,543 | -$4,570 |
| 9 | $1,898 | $0.198 | $300 | $1,598 | -$2,972 |
| 10 | $1,954 | $0.204 | $300 | $1,654 | -$1,318 |
| 11 | $2,012 | $0.212 | $300 | $1,712 | $394 |
| 12 | $2,072 | $0.219 | $300 | $1,772 | $2,167 |
| 13 (inverter) | $2,134 | $0.227 | $2,300 | -$166 | $2,001 |
| 14 | $2,198 | $0.235 | $300 | $1,898 | $3,899 |
| 15 | $2,263 | $0.243 | $300 | $1,963 | $5,863 |
| 16 | $2,331 | $0.251 | $300 | $2,031 | $7,894 |
| 17 | $2,401 | $0.260 | $300 | $2,101 | $9,994 |
| 18 | $2,472 | $0.269 | $300 | $2,172 | $12,166 |
| 19 | $2,546 | $0.279 | $300 | $2,246 | $14,412 |
| 20 | $2,622 | $0.288 | $300 | $2,322 | $16,734 |
| 21 | $2,700 | $0.298 | $300 | $2,400 | $19,134 |
| 22 | $2,781 | $0.309 | $300 | $2,481 | $21,614 |
| 23 | $2,863 | $0.320 | $300 | $2,563 | $24,178 |
| 24 | $2,949 | $0.331 | $300 | $2,649 | $26,827 |
| 25 | $3,037 | $0.342 | $300 | $2,737 | $29,563 |
How to Use This Solar Panel ROI Calculator
This calculator helps you determine whether solar panels make financial sense for your home by modeling the full cost, incentives, savings, and return on investment over 25 years.
Quick Calculator
Enter your System Cost (get quotes from 3+ installers), the Federal Tax Credit (currently 30% through 2032), any State/Local Incentives, your Current Monthly Bill, your Electricity Rate (from your bill), and estimated System Size and Annual Production (your installer will model this). The result shows your net cost after credits, monthly savings, payback period, and 25-year savings.
Advanced Analysis
The Savings Timeline shows year-by-year savings with electricity rate escalation. The Home Value Impact tab shows how solar affects your home's resale value per NREL research. The Financing Options tab compares cash purchase, solar loan, and lease.
Professional Simulator
The Full 25-Year Model includes panel degradation, annual maintenance, and inverter replacement — the true complete picture. Net Metering models your export credit for excess production. Battery Storage models the ROI of adding a battery.
Solar ROI Formula
Annual Savings = Annual kWh Production × Electricity Rate
Payback Period = Net System Cost / Annual Savings
25-Year Savings = Sum of Annual Savings with Rate Escalation and Panel Degradation
ROI = (25-Year Savings − Net Cost) / Net Cost × 100
The 30% federal solar Investment Tax Credit (ITC) is a dollar-for-dollar reduction in your federal income tax bill — not a deduction. On a $25,000 system, you get $7,500 off your taxes. You must have sufficient tax liability to claim the full credit; unused credit can be carried forward.
Example: 8kW System in Phoenix, AZ
The Rodriguez Family's Solar Installation
The Rodriguez family in Phoenix pays $220/month in electricity ($0.12/kWh). They installed an 8kW system for $24,000.
| System cost | $24,000 |
| Federal tax credit (30%) | −$7,200 |
| Arizona state incentive | −$1,000 |
| Net cost | $15,800 |
| Annual production | 12,000 kWh |
| Annual savings (year 1) | $1,440 |
| Payback period | ~11 years |
| 25-year savings (with 3.5% rate increase) | ~$54,000 |
| Home value increase (4%) | +$960 |
Phoenix's high sun exposure (300+ sunny days/year) makes it one of the best solar markets in the US. With Arizona's net metering program and state tax credits, the Rodriguez family breaks even in 11 years and saves over $38,000 net over 25 years.