What goes into a solar design? Besides simply where the solar panels go on your roof, a good solar design takes into account local codes, your home’s electrical information, and racking equipment specs. Here’s a peek behind the scenes at solar designs, from the Solargraf you receive from your sales rep to the technical design stamped by an engineer.
First Things First: Your Personalized Solargraf
When you first meet with an Uprise team member, whether virtually or in person, they’ll provide you with your Solargraf, which we sometimes refer to as your solar design. Your Solargraf assesses your home’s solar potential with tools from the National Renewable Energy Laboratory, such as their PVWatts solar calculator. PVWatts provides hyper-local data, including historical weather patterns and information on solar radiation, to come up with estimates of how much energy a solar array on your roof would produce.
These production estimates will give you a sense of how much money you can expect to save. And when you send us past electrical bills, Uprise will be able to provide an even more precise estimate of your savings. Your Solargraf will show you financial information such as your estimated payback period and your return on investment.
You’ll also be able to see where our team will probably install your panels. When they put together your Solargraf, our sales team looks at potential obstructions and shading from nearby trees or buildings to assess the ideal placement for solar panels.
Bring your questions about the design, financial information, roof layout, or any other solar questions you may have to that initial conversation! And when you’re ready to move forward, you’ll sign your Solargraf to get started with Uprise.
Getting Into Even More Detail: The Site Visit
Next, our construction team will reach out to schedule your site survey or site visit. This visit is our opportunity to actually get up on your roof and check things out. The team will come to your home and obtain accurate measurements of your roof, plus details about your electrical setup from your home’s main service panel, or breaker box. We need to know everything from the exact roof dimensions to the amps of the main service panel to ensure we’re sizing your system properly.
We’ll assess the condition of your roof as well. If you need repairs or a full replacement, our in-house roofer TJ Bobbitt, who’s been roofing in the DMV for nearly 30 years, can provide those services for you. (Check out his work here!)
Nuts and Bolts: The Solar Design
All the site visit information goes into the technical design that our construction team will reference during the actual install. It’s much more in depth than the Solargraf, and is stamped by an engineer. Below, we’ll show you images from a sample design; note yours will differ based your house’s particular details.
Solar Design: Cover Page
A solar design starts with a cover page, which lists details like relevant building and electrical codes followed, the roof type, and the scope of work. The cover page also contains the engineer’s stamp.
Solar Design: Site Map & PV Layout
The next page shows a diagram of the roof, including the location of the panels and fire setbacks, or space included in solar designs allowing firefighters to move around on the roof if necessary. (These are required by DC’s Department of Buildings and are safety features in solar designs around the country.) You can see in the example below that the fire setbacks are 18 inches.
You can see there are 10 solar modules in this design, and 10 microinverters. (Each panel connects to its own microinverter.) This 10-module array will be installed on a TPO roof with a pitch of two degrees. Flat roofs typically have pitches between zero and 10 degrees, while sloped roofs typically have pitches of 20 to 45 degrees.
The roof orientation on this design is 225 degrees, which means the roof faces southwest, a great direction for solar. This page also includes the total roof area (749) and how much space the panels cover (220, or 29.37%).
Solar Design: Electrical Line Diagram
The next page is the one our electrician will reference as they complete the system wiring. Rather than being a map of the roof, it’s a map of the electrical setup. You’ll see the wires move through a junction box (j box), which is typically on the roof. The wires run through conduit down to the side, front, or back of the home (depending on whether you live in a rowhouse or a historical district, or simply where there’s available space), to the combiner box and AC disconnect. Then there’s the main service panel, where the electrician will install the breaker for your solar panels, and finally the meter. (Again, this is just a sample design, and yours will be tailored to your home’s electrical system.)
Other Solar Design Pages
Another page, shown below, has a map of the property, and shows the location of the meter, main service panel, AC disconnect, and combiner box.
There’s also a page showing the details of the roof attachments, and how much the system weighs.
The final pages of our solar design include data sheets provided by the companies that manufacture the equipment and panels. The design also includes Uprise’s Bill of Materials, or BOM, which lists all the equipment we need, from the panels all the way down to the literal nuts and bolts. The BOM helps our construction team pack the van for the job.
Again, an engineer checks out the plans and calculations to make sure everything’s in order before our team arrives at your home for the installation. After the installation, the inspector will also reference the design as they evaluate the project.
We Can Help You Go Solar!
If you’re considering solar for your roof, give us a shout. We’d be happy to create a Solargraf for your roof and go over it with you. Get in touch with our team here or call us at (202) 750-5718 to get started.
And if you’d like to learn more about the solar installation process, here are a few relevant blog posts: