Your roof is an asset. Find out what it earns.
Free residential solar design and analysis calculator. Get accurate design and performance estimates for your address.
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Built on Google Solar imagery and PVWatts® modeling, the same data installers use. Works for most US urban and suburban addresses. Nothing is saved without your consent.
Most free tools scale a national average by your bill. This one models your building in 3-D, places panels on real roof planes, and simulates production hour by hour. Then it compares cash, loan, lease and PPA over 25 years.
It also shows what the leasing company makes on your roof. We have not found another free tool that does.
Send us your email and home address and, within one business day, we'll send you a detailed analysis of your own home: your roof, your utility's actual rate, the payback and savings whether you pay cash, finance, lease or sign a PPA, and whether a battery earns its keep. Free, and with no obligation.
If the numbers are good, we'll say so plainly. If you then want to go ahead, we'll introduce you to the one local installer worth talking to, chosen through an eight-step vetting process (learn more): licensed, insured and certified, with its own crews, no disciplinary history or predatory financing, and still around in ten years to honor the warranty.
Go solar through that introduction and we pay you up to $500 from the fee the installer pays us.
No phone number, and nobody will call you.
Paste a quote. It pulls out the price, size, financing and the escalator buried on page eleven, then checks them against an independent model of the same roof. Built by a former renewable energy research scientist.
We are not selling you the system, so we have no reason to flatter the quote.
Paste the pricing and equipment lines from an email, a PDF or a forum post — messy is fine. We read it, show you what we found, and change nothing until you say so. How this works ↗
The text you paste is sent to our reading service to be interpreted, then discarded — it is never saved. Remove your name and address first if you'd rather.
The best design for your address
Every panel is placed where it earns the most on your roof, and the system is sized to your bill. Change the bill or the panel count and this updates.
Design it yourself
See every panel on your roof, choose which ones to use, and correct each roof face. Free with an account.
Your solar snapshot
Ways to pay — and what each could save you
Estimated with standard assumptions for this location and system. These four financing paths are the same ones full members can fine-tune input by input.
Crunching the numbers…
Informational estimate, not an installation quote. “25-yr savings” is cumulative and net of what you pay (purchase, loan, lease, or PPA). Battery storage is not included in this snapshot. See the full methodology.
Get your full analysis — free
Adjust every assumption, add battery storage, compare net-metering and time-of-use
scenarios, see hourly production & battery dispatch, audit the lease/PPA fund math,
and export a complete proposal. An account also switches the model to PVWatts'
own hour-by-hour weather for your roof instead of a modelled average day, which is
the difference between a battery estimate and a battery guess. Create a free account
and it's all yours — plus up to 3 saved projects you can reopen on any device.
No phone number, and nobody contacts you. Installer
matching is coming later, and only ever happens if you explicitly ask for it.
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Planning to move?
Few people stay put for 25 years, and leaving early is where these deals differ most. If you sold in year we will show where you would stand.