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.
or
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 report on your own home, about 25 pages: your best system with and without a battery, the payback and savings whether you pay cash, finance, lease or sign a PPA, what changes the answer (your bill, the system's size, an EV, the price you pay), every incentive that applies to you, and a detailed shading analysis of your roof. 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.
We ran detailed studies on over 100 randomly chosen homes with the same calculator you have access to here. In our blog, we publish every detail, including the ones that don't flatter solar. Nothing is cherry-picked; every roof is measured individually.
Every figure in those studies came out of this calculator, and you can reproduce any of them on your own address in about a minute. That is the point of reading them: they show you what this tool is actually doing with your roof.
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.
A drawing, not your roof. With a free account this runs on your own home, with your own panels and your own numbers.
A shade-aware design in seconds, whatever you know about solar. Design Studio ranks every spot on your roof by the sun it actually gets, places the panels on the best ones, and skips what your trees shade. You do not have to understand any of it for it to be right.
Then change anything you like. Resize the system, drop a panel on a different spot, correct a roof face — or reset to the best layout in one tap.
The design above is already the best one for your roof. An account lets you change it by hand; it is not needed to trust the numbers.
A drawing, not your roof. With a free account this plays on your own home, from Google’s 3-D model of it.
Your results already include your roof's shading. Every panel's output is measured from Google's 3-D model of your home and the trees around it, so the design, production and savings you see here account for it.
With a free account, you can watch it. Shade Studio plays the shade across your own roof, hour by hour and month by month, and lights up each panel as the sun reaches it.
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.
Already have an account? Sign in
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.