Your quote against a public benchmark
Rooftop Payback Estimator
Bring a real quote if you have one. The tool prices it against the NREL 2024 residential benchmark of about $3.25 per watt DC, estimates first-year production from the planning factor for your area, and computes simple payback and a 25-year net with slow panel degradation and flat electricity prices. Change any input; the defaults are a stated example, not a market survey.
- NREL benchmark, checked October 4, 2026
- No federal credit assumed after 2025
- Only incentives you confirm are counted
At $3.25 per watt, this quote is in the neighbourhood of the NREL 2024 residential benchmark of $3.25 per watt (checked October 4, 2026). Equipment, roof work, and warranty decide whether it is fair.
- Quoted price per watt
- $3.25
- Estimated first-year production
- 13,200 kWh
- Share of current usage offset
- About 98%
- Estimated first-year bill savings
- $2,112
- Net cost after incentives you entered
- $26,000
- Simple payback
- 12.3 years
- 25-year net (0.5% yearly degradation, flat rates)
- $23,750 ahead
Planning estimate only. Production depends on roof angle, shade, and weather; savings depend on your tariff and net metering rules, which change. The federal residential solar tax credit ended for systems placed in service after 2025, so this tool assumes no federal credit unless you enter a confirmed incentive yourself. Model your roof in NREL PVWatts and check incentives in DSIRE before deciding.
How to use the verdict
- Below the benchmark: price is unlikely to be your problem. Spend your diligence on equipment, warranties, and the installer.
- Near the benchmark: normal territory. Roof work, electrical upgrades, and equipment tier should explain the exact position.
- Well above the benchmark: the quote owes you a line-by-line explanation and at least two competitors.
Assumptions, printed rather than buried
Payback here is simple payback: net cost after only the confirmed incentives you enter, divided by first-year bill savings, followed by a 25-year net using 0.5% annual panel degradation and flat electricity prices. Savings assume production first offsets usage at the price you enter, capped at your stated annual bill. Production uses the planning factor for the metro you select, which is a starting estimate. Your roof needs its own PVWatts model with its tilt, direction, and shade before any figure deserves your signature. The full method, sources, and review process are on the methodology page.
Limits
- Production factors are planning examples for each metro, not a substitute for a PVWatts model of your roof with its tilt, direction, and shade.
- Savings assume the production offsets your usage at the price you enter. Export rules can lower the value of surplus energy; read net metering explained before trusting a savings figure.
- No federal residential credit is assumed. It ended for systems placed in service after 2025. Incentives you enter must be ones you have confirmed, ideally in DSIRE and with your utility.
Common questions
What does the $3.25 per watt benchmark actually mean?
It is NREL's modeled national residential cost benchmark for 2024, checked October 4, 2026, used here as a comparison line for quotes. It is not a quote, a price cap, or a claim about your installer. Local labor, roof condition, equipment, and electrical work move real prices in both directions. Our quote red flags guide shows how to make a higher quote explain itself.
Why is no federal tax credit in the math?
The federal residential solar tax credit ended for systems placed in service after 2025, so this site assumes none. If a quote subtracts a federal credit anyway, ask the installer to document it in an official source. State, local, and utility incentives still exist in places; confirm them in DSIRE and your utility tariff, then enter only the confirmed amount. Your state page points to what to verify.
How accurate is the production estimate?
It is a planning estimate built from a metro production factor, stated in kilowatt-hours per kW per year. Your roof angle, direction, shade, and weather will move the real figure. Ask every installer to name the tool behind their estimate and reproduce it in a public model such as NREL PVWatts. The metro pages show how the same system behaves across different sun and prices.
Why does the estimator cap savings at my bill?
Because exported surplus is often worth less than energy you consume, and a bill cannot fall below its fixed charges through production alone in most tariffs. Sizing past your usage buys cheap exports unless your export rule pays retail. Our sizing guide and net metering guide show how to size against the rule you actually live under.
Sources and verification
Cost basis: National Renewable Energy Laboratory, U.S. Solar Photovoltaic System and Energy Storage Cost Benchmarks (residential about $3.25 per watt DC, 2024; checked October 4, 2026). Production method: NREL PVWatts planning approach. Price context: U.S. Energy Information Administration residential price data. Incentives: DSIRE. Full detail on the methodology page. This tool provides educational planning estimates, not a quote.