Solar Cost Calculator — 2026 Net Cost
A solar quote that says 'after incentives' is only as honest as the incentive list behind it. In 2026 that list should not contain a 30% federal credit for a system you own. This calculator itemizes every line — array cost from…
What this estimate does
A solar quote that says 'after incentives' is only as honest as the incentive list behind it. In 2026 that list should not contain a 30% federal credit for a system you own. This calculator itemizes every line — array cost from kW × $/W, optional storage at $/kWh, verified state credits and grants, a confirmed utility rebate, and an explicit $0 federal residential credit — then shows the net cost that actually has to be financed or paid. Where a state program is capped, the cap is applied; where we could not verify a statewide program, the line is $0 and the page says so rather than inventing a number.
Your inputs
Change any default to match your bill, your quote and your utility tariff.
Household and price
Roof and solar resource
Money, financing and 25-year assumptions
Your estimate
Federal residential credit (2026)
$0.
Itemized cost
Ownership comparison · 25-year net
| Cash purchase | — |
|---|---|
| Loan (after payments) | — |
| Lease / PPA (no upfront) | — |
| Loan monthly payment | — |
The cash and loan rows both exclude any federal credit. A third-party owner, not you, may claim section 48E.
Environmental scale
| CO₂ avoided in year one | — |
|---|---|
| Mature-tree equivalent | — |
| Gasoline car miles | — |
Uses 0.855 lb CO₂/kWh (U.S. grid average), 48 lb/tree/year and 0.89 lb/mile.
25-year cumulative net cash flow
Sensitivity to utility rate escalation
| Annual escalation | Payback | 25-year net |
|---|
Year-by-year cash flow
| Year | Production kWh | Bill savings | Maintenance | Net | Cumulative |
|---|
How this is calculated
Array cost = kW × 1,000 × installed $/W. Battery cost = usable kWh × $/kWh. Gross cost is the sum. A percentage state credit is min(percentage × array cost, statutory cap); a flat grant is the published amount, capped at array cost. The federal credit is a constant 0 in 2026 following the termination of IRC section 25D — we show the line rather than deleting it so a reader can verify it was not applied. Utility rebates are user-entered because they are utility- and territory-specific. Net cost = gross − state credit − federal credit − rebate, floored at zero.
A worked example
A 6.0 kW array at $2.80/W is $16,800. In New York, the 25% state credit capped at $5,000 contributes $4,200; the federal credit contributes $0; with no utility rebate the net cost is $12,600. In a state where we could not verify a statewide credit, the same array nets $16,800. Add a 10 kWh battery at $700/kWh and gross cost rises by $7,000 — but note that most state credits in our table apply to the array, not the battery, and the homeowner battery credit under §25D also ended in 2025.
What this tool does not do
It excludes sales tax, permitting, a main-panel upgrade, roof repair, trenching for a ground mount, tree removal, and dealer fees embedded in financing. It does not price a specific installer. Marketplace averages and full-market medians differ by as much as a dollar per watt, which is why the $/W field is always editable.
Practical checks before you compare quotes
- Compare quotes on $/W before incentives, not on monthly payment.
- Ask the installer to identify each incentive by program name, not just a discount.
- Confirm the state credit's carryforward rules with a tax professional.
- Get the cash price and the financed price as two separate numbers.
Common mistakes
- Accepting a '30% off' line on a 2026 proposal.
- Applying a state credit percentage to the battery when the statute covers the array only.
- Forgetting that a non-refundable credit needs tax liability.
- Treating a marketplace average as a quote.
Planning estimates only — not a quote, tax advice, legal advice or financial advice. State benchmarks are not your utility tariff. Verify every incentive with the program administrator and get at least three written installer quotes.
Frequently asked questions
What does solar cost per watt in 2026?
EnergySage marketplace quotes averaged about $2.60/W nationally in 2026, while LBNL's Tracking the Sun reported a $3.60/W median for host-owned systems in the 2025 install year (about $3.00/W for cash purchases). Those are different populations; enter your written quote rather than either average.
Does the 2026 federal credit apply to a battery?
No. Standalone or solar-paired batteries owned by the homeowner were eligible under §25D through 2025; that credit ended December 31, 2025. Some state and utility battery rebates, such as California SGIP, remain but are territory- and income-dependent.
Why is my state credit $0?
Because we could not verify a currently available statewide residential solar tax credit or grant for that state in our November 2026 review. That is not a claim none exists — check DSIRE and your utility, then enter a confirmed amount as a utility rebate.
Are SRECs or SMART payments included?
No. Production incentives depend on registration, capacity blocks and utility territory. They are described on state pages and can be entered as a rebate if you have a confirmed dollar amount.
Sources and further reading
- HelioCalc methodology and calculation kernel
- IRS FS-2025-05 (2026 federal credit rule)
- EIA Electric Power Monthly, Table 5.6.A, August 2026