If you’ve found our site, chances are good you’re thinking about getting solar panels for your home. During that process, one of the first and most important questions to ask yourself is “is my home right for solar?”
And fortunately, the answer is pretty simple. Here are the ingredients of a great solar home, in order of importance:
- A lack of shade
- The right location
- Roof orientation
- Roofing material and shape
Let’s jump right into how all these variables work together to make a home perfect for solar panels:
Shade is generally a desirable thing to have on your property. It can reduce the need for cooling your house in the summer, and makes a nice spot for sipping a cold beverage of your choosing after finishing yard work for the day.
But the ideal place for solar has no shade at all. If your house has an unshaded roof or open ground space, you’re golden! If you’re buying a house with solar in mind, look for one with a good, unshaded south-facing roof.
Solar panels can make electricity with just a little bit of light (even on cloudy days!), but if you have a roof that’s even partially shaded, part of the time, it can mean big problems for your solar potential. That’s because shade on even a small portion of a panel affects the output of the whole thing.
The little squares you see on a solar panel are individual cells. Those cells are wired together in a row (called “series wiring,”) and electricity flows through wires between them like water flows through pipes. Shade on just one of the cells in a panel is like a clog in a section of a pipe, causing the electrical current to drop to a trickle for that panel, and reducing its ability to put out electricity.
The problem gets even worse if you have multiple panels wired together in a series, connected to a single DC/AC inverter. The whole string of panels can only put out as much energy as the weakest panel in the series. Here’s how it works:
How you can fight the problems of shade
Having a shady roof doesn’t have to be the end of your solar dreams. There are multiple ways to overcome the challenges of shade. here are the best places to start:
Get panels off the roof
If your roof is shady, but you have a shade-free area on your property, you’re set! You can mount solar panels on the ground, and maybe even save a few bucks in the process. Ground-mounted solar panels are installed on galvanized steel structures that can be sunk into the ground with concrete footings, meaning easier maintenance and no need for putting holes in your roof.
If you’d rather not use up valuable ground space, you can install solar on a shed or outbuilding, too. Or build a solar carport, which can benefit you in multiple ways.
There is a way to overcome the problems we described above that occur when one panel is shaded. Microinverters make each panel into its own island, ensuring that each panel puts out as much electricity as it can. When one panel with a microinverter is shaded, its output goes down, but the rest of the system is unaffected.
Here’s an updated version of the above image:
Microinverters also provide added benefits. Each one can be monitored individually for problems with low output or connectivity, making it easy to see if a panel isn’t living up to its warrantied specifications. This situation is rare, but can be very frustrating without the help of microinverter monitoring.
If your roof is only a little shaded for part of the day, tree trimming can be a great solution to your problems. You’ll have to do it every couple of years, and stay vigilant for any stray branches that seek to harsh your solar mellow, but shade on solar panels really is that big of a problem.
Location, location, location
Don’t hate us for telling you so, but it’s possible to live in the wrong state. Some places in the USA rely overwhelmingly on coal and natural gas, and have cheap electricity that makes home solar power less economical. Other places are Alaska, where the sun doesn’t shine much for a good portion of the year.
But even in states with cheap electricity, state lawmakers have a lot of power. If your state government has passed good solar laws that encourage renewable generation, ensure access to net metering, and even provide some incentives for home solar power, you can rest assured that solar can be great in your state.
And the good solar states are more numerous than you might think. Check out our annual State Solar Power Rankings Report, where we break down how each state scores on 13 factors that lead to good solar investment potential. Click through to your state’s specific page for detailed information about installing solar in your state.
It’s pretty simple: in the northern hemisphere (where you live if you’re in the USA), solar panels should face south. So say it again with us: “the ideal home for solar has a large, unshaded south-facing roof” (we have a feeling that’s gonna be the catchphrase of the summer).
But if your house doesn’t have a large, unshaded south-facing roof, don’t despair! There’s a reason this is third on our list of important ingredients of a solar home. West-facing panels can also be great, especially if your utility company offers a time-of-use billing option, under which energy is more expensive during late afternoon “peak” times, when more people are using electricity and more sun is shining on west-facing roofs.
Your roofing material and shape
The final ingredient in making a home right for solar is the roof itself. Ideally, you’ll have a rectangle-shaped roof (i.e. a gable roof) with standing-seam metal or asphalt shingles on top of it. Here’s why:
Solar panels can be installed on almost any kind of roofing material, from cedar shake shingles to rubber roofs. But the methods to mount the panels can vary widely by roof material, and that can increase the cost dramatically.
Like we said just above, a standing seam metal roof is ideal, because the panel racks can be attached to the seams with clamps, eliminating the need to drill into the roof itself. Asphalt shingles are the second-best type, because they’re the most widespread of all roof types, and installers have plenty of experience working with them, with lots of good options to choose from as far as mounting goes.
To dig deeper into how your roof type can affect your ability to get solar panels, check out our in-depth blog about solar roof attachments.
This one’s pretty simple. Solar panels are rectangles, so if your roof is too, you can fit more panels on it. That’s not to say other roof shapes are bad, necessarily. Hip roofs can be great for solar panels, but you’ll have reduced area to install them. Here’s a comparison for you:
To choose a house that’s just right for solar, either a gable or hip roof can work, but try to avoid too many valleys in a hip roof…