Savings and payback

Break even timeline estimator

Track your cumulative savings year by year against your net system cost, with utility rate growth factored in, to find the exact year you break even.

Current status: the 30% federal residential solar tax credit (Section 25D) expired for systems placed in service after December 31, 2025. If you're buying with cash or a loan in 2026 or later, use your full system price with no credit subtracted. Only subtract 30% if your system was placed in service by the end of 2025.

Your numbers

1 Project details Optional
Shown on your exported report. Leave blank to skip.
2 System cost
Total price after any upfront incentives, like the federal tax credit. 0% federal credit is the accurate default for a new purchase in 2026 or later; use 30% off only if your system was placed in service by 12/31/2025.
3 Savings and rate growth
Use the result from the solar savings calculator if needed.
Historical US residential rates rise about 2 to 3% a year on average.

How it works

Three steps to your break-even year

Step 1

Start with your net system cost

Use your installed price after incentives. If you haven't calculated this yet, the payback period calculator walks through it step by step.

Step 2

Enter year-one savings and expected rate growth

Pick a growth rate that matches your utility's history, or use 0% for a conservative flat estimate that matches a simple payback calculation.

Step 3

Read the year your savings cross your cost

The tool adds each year's growing savings to a running total until it reaches your net cost. For a full year-by-year table instead of a single crossing point, see the year by year breakdown tool.

Understanding your break-even timeline

Why break-even and payback aren't quite the same

A simple payback period divides net cost by a single savings figure and treats every year the same. A break-even timeline adds up real, growing savings year by year instead. A $22,000 net cost with $1,800 in year-one savings and 3% annual rate growth crosses break-even around year 10.6, noticeably faster than the flat 12.2 year payback number. The system size by square footage, quick estimator is the quickest way to check whether the system size behind this estimate fits your roof and usage.

How much rate growth actually matters

US residential electricity rates have historically risen around 2 to 3% a year, though some regions and years have seen sharper increases. Even modest growth compounds over a 7 to 10 year window, since each year's higher rate applies to your full offset amount. The rate increase sensitivity calculator lets you test a wider range of growth assumptions against the same system. The US Department of Energy's homeowner's guide to going solar walks through the same decision step by step.

What a 0% growth rate tells you

Setting rate growth to 0% turns this tool into a flat payback calculation, matching the result you'd get from the payback period calculator. Use that setting as a conservative baseline before layering in any rate growth assumption. If your production estimate feels uncertain, the first year output estimator gives you a second check on annual output.

What this timeline leaves out

This tool holds system output constant and only varies the utility rate. Real systems lose a small amount of output each year to degradation. Combine this result with the degradation loss tool for a more complete picture, or check the cumulative savings graph generator to visualize the full curve. Utility rates drive the whole savings calculation, and the US Energy Information Administration's electricity data track them state by state.

Questions

Frequently asked

A payback period is a single number from dividing cost by savings. A break-even timeline tracks cumulative savings year by year, which matters once you factor in rising utility rates. A $22,000 net cost with $1,800 in year-one savings and 3% annual rate growth breaks even around year 10.6, faster than the flat 12.2 year payback number.

Since your savings grow a little each year as utility rates rise, later years contribute more toward paying off the system than a flat estimate assumes. Even a modest 3% annual increase compounds meaningfully over 7 to 10 years.

Historical US residential electricity rate increases average around 2 to 3% a year, though some regions have seen higher spikes. Using 0% gives you the same result as a simple flat payback calculation if you want a conservative baseline.

No, this tool assumes constant production and only varies the utility rate. For a version that also factors in the roughly 0.5% annual output decline typical of most panels, use the savings loss from panel degradation tool.

Related tools

Keep exploring your timeline

Payback period calculator Rate inflation projection tool Rate increase sensitivity Year by year savings breakdown Cumulative savings graph generator Savings loss from degradation Simple vs discounted payback All savings and payback tools