Use your actual electricity rate, export credit and installation quote to see year-one savings, payback and 25-year savings, with every assumption shown.
Solar savings calculator
What could solar save you, and when would it pay for itself? Bring your production estimate (from our solar potential calculator or an installer's quote), your electricity price and the quote. Every assumption is visible and yours to change.
Assumptions and limits
- No federal tax credit: the 30% Residential Clean Energy Credit (25D) does not apply to systems installed (completed) after December 31, 2025 (IRS). Check state and utility incentives at DSIRE and enter them as a rebate.
- Savings each year = energy you use yourself × your price + energy you export × the export credit. Net metering credits exports at about your retail price; net billing (for example California since April 15, 2023) pays less (CPUC). Your utility’s tariff decides.
- If you enter your current bill, savings can’t cut the bill below the fixed monthly charge.
- Electricity price growth: 2.5% a year by default. That is an assumption, not a forecast; the table shows lower and higher paths. (The U.S. average rose from 17.01¢ to 18.19¢ between Jan–Jul 2025 and Jan–Jul 2026, EIA Electric Power Monthly, Table 5.6.B (Sept 2026).)
- Panel output drops 0.5% a year (median of nearly 2,000 measured degradation rates, Jordan & Kurtz, NREL, Photovoltaic Degradation Rates).
- Not included: financing, inverter replacement, maintenance, insurance, roof work, property-tax effects or changes to your tariff.
- Payback = years until cumulative savings equal the quote minus rebates.
- This is an estimate, not a design. A licensed installer must confirm sizing, wiring and permits.
Learn more in our Solar guide, or see all calculators.