If you have ever stood in your yard in Chicago and wondered whether panels would actually fit on your roof, and what they would look like up there, Windfree Solar now has a solar potential calculator on windfree.us that answers the question with a picture. Enter your address and the tool draws a solar design on your actual roof, along with an estimate, usually in about 20 to 25 seconds.
The tool is built by Aurora Solar, a solar design software company whose platform has been used to design more than 20 million solar projects, according to Aurora Solar. This guide covers where to find it on our site, what it shows you, what it cannot see from above, and how to take the design further with Windfree’s team. Windfree Solar has been designing and installing solar in Illinois and the Midwest since 2009.
Summary
- The solar calculator on windfree.us opens from the “Solar Calculator” link in the top menu and from the “See Potential Savings” button on our residential solar page.
- Enter your address and the tool returns a solar design on your own roof plus an estimate, typically in about 20 to 25 seconds, with a progress bar while it works.
- The design is built from aerial imagery. Some addresses, such as new construction, may not have imagery yet, and the tool will tell you so.
- Solar is custom. Sun exposure, roof condition, electrical service and your actual electricity usage still decide the final system, so the design is where the conversation starts.
- When you are ready to go further, Windfree’s team can take your design into a full proposal and site review.
Where to Find the Solar Calculator on windfree.us
There are two ways in, and both open the same tool in a popup window on the page you are already on.
- The top menu. Click “Solar Calculator” in the main navigation at the top of any page on windfree.us.
- The “See Potential Savings” button. You will find it on pages such as our residential solar page.
How to Get a Solar Design for Your Roof
- Open the tool. Click “Solar Calculator” in the top menu, or the “See Potential Savings” button on the residential solar page.
- Enter your address. Use the address of the building you are thinking about putting solar on.
- Give it about 20 to 25 seconds. A progress bar shows the tool working while it builds the design.
- Look at your roof. You will see a solar design laid out on an image of your own roof, plus an estimate.
- Bring it to Windfree. Your request reaches Windfree Solar’s team. If you want to take the design further, contact us and we can talk through a full proposal and site review.
What the Design Shows You
For most people, the hardest part of thinking about solar is picturing it. A drawing of panels on your own roof makes a few things clear right away.
- Whether panels fit. You can see how the layout works around the shape of your roof.
- Which roof planes carry the array. In Chicago, south facing planes capture the most sun over a year, and east and west facing planes are used regularly too. Our guide to telling whether your roof is a good fit goes into orientation in more detail.
- What it would look like. On a home you care about, how the panels sit on the roof matters, and the design gives you a first look.
- An estimate to start from. The tool gives you a number to begin the conversation with.
What an Aerial Design Cannot See
The tool works from aerial imagery, which is what lets it draw a design on your roof in seconds. A picture from above has limits, and they are worth knowing before you plan around the result.
- Sun exposure through the year. A parkway tree, a taller building next door or a chimney can shade your roof at different hours and in different seasons. Sun exposure is confirmed on site, and a better site produces a better return.
- Roof age and condition. Panels are a long term addition. If the roof under them is near the end of its life, that belongs in the same conversation as the solar.
- Your electrical service. Panel capacity and where the system ties in are part of the design, and they are checked in person.
- Your actual usage. System size follows how much electricity your home uses. Twelve months of utility bills tell us far more than any image.
- New construction. If your home is new, the imagery may not show it yet, and the tool will let you know. In that case, contact us directly.
This is why we still talk about a site review. We wrote about the gap between an online number and a proposal you can build from in our guide to Illinois solar estimates. The design gives you a picture of your own roof to start from, and the site review fills in what the picture cannot show.
How Incentives Fit In
The federal residential clean energy credit under Section 25D applied to systems placed in service through December 31, 2025, and does not apply to systems placed in service in 2026. For Illinois homeowners, Illinois Shines, the Illinois Power Agency’s Adjustable Block Program, and net metering are what shape net cost now. Illinois Shines is a state incentive that supports solar PV development through the purchase of renewable energy credits (RECs), and Windfree Solar is an Approved Vendor under the Illinois Shines program.
Net metering credits the power your system sends back to the grid. Our post on how ComEd net metering credits work explains the mechanism, and our honest read on whether solar is worth it in Illinois walks through the 2026 picture for homeowners. How any of this applies to you depends on your situation. Check with your tax advisor. We don’t give tax advice.
Taking Your Design Further With Windfree
When you are ready to move past the first look, Windfree’s team can take your design further with a full proposal and site review, built around your roof, your sun exposure and your usage. We manage the full scope of a project: sales, engineering, permitting, procurement of materials, interconnection, inspection and permission to operate (PTO), the utility’s approval to switch your system on.
Windfree Solar has installed 1,200+ systems across Illinois and the Midwest since 2009. We are a Certified Minority Owned Business (MBE) and an Equity Eligible Contractor (EEC). We are also a Solar Insure certified provider, which not every installer can be, and on qualifying systems that means a 30-year warranty covering equipment and labor.
If you would like to see more of our work first, browse our projects page, or read our plain-English guide to how solar panels work.
Frequently Asked Questions
Where is the solar calculator on windfree.us?
Click “Solar Calculator” in the top menu on any page, or click the “See Potential Savings” button on the residential solar page. Both open the tool in a popup.
How long does it take to get my solar design?
Typically about 20 to 25 seconds after you enter your address. A progress bar shows the tool working while it builds the design.
What if the tool says it cannot find imagery for my address?
The design is built from aerial imagery, and some addresses, such as new construction, may not have imagery yet. Contact us, email sales@windfree.us or call 312-588-6953, and we can look at your home directly.
Is the design the system Windfree would install?
It is a starting point. Solar is custom, and the final system depends on your sun exposure, roof condition, electrical service and usage, which a full proposal and site review confirm.
Does solar only work on houses?
Solar can go on almost any building, including garages. For a business or a new commercial building, the planning is different, so contact us to talk through the project.
See Solar on Your Own Roof
The quickest way to picture solar on your home is to try it. Click “Solar Calculator” in the top menu, or the “See Potential Savings” button on our residential solar page, and enter your address. When you want to go further, contact Windfree Solar, email sales@windfree.us, call 312-588-6953, or stop by the Windfree Solar Cafe at 517 Dempster Street in Evanston.
