Step 1 is optional — drop a pin on the map for a real production estimate, or skip straight to Step 2 and enter your own numbers. Manual entry always works on its own.
Step 1 — Find Your Location (optional)
Type your address to pull a real production estimate for your area. Prefer not to?
Or use the map: click anywhere on it to drop a pin at your approximate location, then tap "Use This Location" in the popup that appears to confirm.
Map isn't available right now — that's fine, just enter your numbers manually in Step 2 below.
Step 2 — Your System & Costs
Not sure what a field means? Tap the ⓘ next to its label.
Don't know yours yet? Estimate it with the Panel Size Calculator →
Note: there are currently no federal solar incentives. This state list is a work in progress — check your state energy office if yours isn't shown yet.
Your Results
A direct comparison of your current monthly electric bill against your estimated bill after solar, based on the system size and offset entered above.
How your net savings build year by year over a typical 25-year system lifespan, after subtracting your upfront system cost.
Results are for reference and estimation only. Verify all values before making any financial decision. See full disclaimer below.
Solar quotes are full of terms most calculators don't explain. Here's what each one in your results actually means.
Payback Period
How many years it takes for your accumulated bill savings to equal what you spent upfront on the system. A shorter payback period means you break even sooner — but a longer payback period doesn't necessarily mean a bad investment, since savings keep accumulating for the full life of the system afterward.
Net Present Value (NPV)
NPV converts every future year's savings into what that money is actually worth today, using a discount rate to account for the fact that a dollar saved 20 years from now is worth less than a dollar saved this year — inflation and lost investment opportunity both matter. A positive NPV means the system is worth more, in today's dollars, than what you paid for it.
Internal Rate of Return (IRR)
IRR expresses your solar system as an annualized percentage return, the same way you'd talk about a stock portfolio or a savings account's interest rate. It's the single number that makes it possible to directly compare "put $18,000 into solar" against "put $18,000 into an index fund" on equal terms.
25-Year Net Savings
The total dollar amount you come out ahead over a typical 25-year system lifespan, after subtracting your original system cost from all the bill savings accumulated along the way. This is the simplest, least technical number in your results — the actual dollars in your pocket by year 25.
Why There's No Federal Tax Credit in This Math
The federal residential solar credit (Section 25D, the 30% credit many people still expect) ended for cash and loan purchases installed after December 31, 2025. It's only still available indirectly through a lease or power purchase agreement (PPA), which this calculator doesn't model, since it's a fundamentally different financing structure. If your state offers a real incentive, it's reflected in your results — the federal credit no longer applies to the purchase type this tool assumes.
This guide is provided for educational and reference purposes. Always confirm your specific financial and tax situation with a licensed tax professional or financial advisor before making a purchase decision.