Solar Panel ROI Calculator

Estimate solar payback, 25-year savings, and ROI using current 2026 federal rules plus only the state, local, or utility incentives you enter.
System details
System size (kW)
kW
Example size — replace with your proposed system
Cost per watt installed
$
Example estimate — replace with an installer quote
Annual electricity use
kWh
Example usage — replace with your utility bills
Location & utility rate
Illustrative preset: $0.16/kWh · 4.5 daily sun hours. Verify both for your site and utility.
Incentives & rebates
Federal Section 25D (2026)
$0
0% for property placed in service after 2025
State / local incentive
$
Default $0 — enter only a confirmed amount
Utility rebate
$
Default $0 — enter only a confirmed amount
Effective-date/source note. For current 2026 calculations, the federal credit is 0%. IRS guidance states that the 30% Residential Clean Energy Credit applied to qualifying property installed from 2022 through December 31, 2025 and is not available for property placed in service after December 31, 2025. IRS Residential Clean Energy Credit (Section 25D). State, local, and utility incentives are separate and are included only when entered above.
Assumptions
Annual rate increase
%/yr
Estimate; applied beginning in year 2
Panel degradation
%/yr
Estimate; applied beginning in year 2
Financing
Payback period
14.3 yrs
Simple payback: cost basis ÷ year 1 savings
25-year net savings
+$33,337
$57,337 modeled savings − $24,000 cost basis
Gross cost
$24,000
Federal §25D credit
$0
Net cost
$24,000
Year 1 savings
$1,680
Annual production (80% factor)
10,512 kWh
Offset percentage
100%
System ROI (25yr)
139%
Savings projection
YearAnnual savingsCumulativeNet benefit
Year 1$1,680$1,680$-22,320
Year 5$1,855$8,836$-15,164
Year 10$2,098$18,828$-5,172
Year 15$2,372$30,125+$6,125
Year 20$2,681$42,897+$18,897
Year 25$3,031$57,337+$33,337
Year 30$3,427$73,663+$49,663
Getting the best solar deal
Get multiple installer quotes and verify production with a site-specific model. For property placed in service after December 31, 2025, this calculator applies no federal Section 25D credit. Confirm state, local, and utility incentives independently and enter only amounts you qualify for. Verify retail rates, export compensation, financing costs, maintenance, and replacement assumptions before committing.
Solar Panel ROI: A Complete Guide

Solar return on investment depends on installed cost, confirmed incentives, actual production, the value of each kWh, financing, and ongoing costs. The figures here are planning estimates, not quotes or guaranteed savings. Current 2026 calculations do not include a federal Residential Clean Energy Credit.

Federal Section 25D effective date. IRS guidance states that the 30% Residential Clean Energy Credit applied to qualifying installations from 2022 through December 31, 2025 and is not available for property placed in service after that date. State, local, and utility programs are separate and vary by location; this calculator assumes zero unless you enter a confirmed amount.

Electricity value is an estimate. Regional rate presets and sun-hour values are illustrative assumptions, not current utility quotes or site studies. The model values production up to annual usage at the selected retail rate and assigns no value to production above usage. Actual tariffs, time-of-use pricing, fixed charges, export compensation, shading, orientation, and weather can materially change savings.

Net metering and excess production. Net metering policies allow you to send excess solar production back to the grid in exchange for bill credits. Full retail net metering — where you receive the same rate for exported power that you pay for imported power — provides the best return. Some utilities now offer reduced rates for exported power, which reduces the value of oversizing your system.

Cash vs. financing. Cash analysis uses net installed cost after only the incentives you enter. Financing analysis uses total scheduled principal and interest. The model does not include lender fees, maintenance, inverter or battery replacement, insurance, taxes, opportunity cost, or lease/PPA terms.

Getting accurate quotes. Compare multiple current installer quotes using total cash price, cost per watt, equipment, modeled production, financing fees, warranties, maintenance, and replacement assumptions. Verify every warranty and production guarantee against the specific manufacturer and installer documents.

Last verified: August 28, 2026.

Frequently Asked Questions — Solar Panel ROI Calculator
Common questions about solar panel payback periods, the federal tax credit, and calculating solar ROI.
Solar ROI is estimated by subtracting the applicable cost basis from modeled electricity savings, then dividing that net benefit by the cost basis. Simple payback is the cost basis divided by first-year savings. The 25-year projection applies the entered utility-rate escalation and panel-degradation assumptions beginning in year 2. Current 2026 calculations use a 0% federal Section 25D credit; state, local, and utility incentives are included only when you enter them.