Solar Panel Cost Calculator

How to use

1. Enter system size in kW and installed cost per watt.
2. Enter expected annual utility savings from generation and net metering.
3. Leave the legacy federal credit at 0 unless a credit still applies to your installation.
4. Read gross cost, net cost, payback years, and 25-year savings.
5. Test a few savings values to see how sensitive payback is to net metering changes.

About this tool

Work the solar economics without the federal credit. The 30 percent residential clean energy credit expired for systems placed in service after December 31, 2025 under the 2025 tax law, so the default credit is 0 and results reflect out-of-pocket cost. Defaults of an 8 kW system at 2.75 dollars per watt cost 22,000.00 dollars gross, which is also the net figure at a 0 credit; at 1,600 dollars of yearly savings the payback runs 13.8 years and 25 years of savings leaves 18,000.00 dollars ahead. The legacy credit box exists for grandfathered or special cases where a credit still attaches; state rebates and utility incentives remain available in places and would shorten payback further. The 25-year math assumes constant savings and ignores panel degradation and inverter replacement. Simplified cash-purchase model: constant savings, no degradation, inverter replacement, financing, or maintenance; credit treatment follows the 2025 federal tax law; verify with official sources; not financial or tax advice.Payback equals net cost divided by annual savings, so a 30 percent legacy credit on the default system drops cost to 15,400.00 dollars and payback to 9.6 years. Net metering policy is the swing factor: lower export credits shrink the savings input and stretch every timeline. Utility rates rising would do the opposite.

FAQ

Rate this tool

Your rating stays in this browser (local storage) — nothing is sent to any server.