Have you heard the myth that solar panels can’t be installed on roofs that face north? Or that solar doesn’t work in rainy states like Washington and Oregon? Sadly, a lot of false rumors exist about solar.
In actuality, solar can work on most roofs, in most areas.
How do you separate the solar myths from the facts? How do you know if solar panels will work on your home? Much like your roof, we’ve got you covered.Download our free Go Solar Guide
Will solar work on my roof?
To know if your roof is a good fit for solar panels, consider these five factors:
1. Solar panel size, solar array size, and roof size
It takes several solar panels to produce enough electricity to power a good proportion of your home — or all of it, if that’s your aim. You’ll want to have a large enough space on your roof to install the set of panels (called a “solar array”). Ideally, this space will be uninterrupted.
If the size of your roof is limited, you may choose to opt for high-efficiency solar panels, which produce around 300–350 Watts each, more power than typical panels.
The more sunlight that solar panels collect, the more electricity they’ll produce and the quicker your system will pay for itself. For those of us in the U.S., a south-facing roof is ideal, as this orientation will maximize the amount of sunlight hitting your panels.
Solar panels can be installed on a roof that faces east, west, or even north, but they will likely produce around 25% less energy than south-facing panels, depending on the roof’s slope.
If your roof is flat, its orientation isn’t a factor. The installer can engineer your solar panels to face due south.
Solar panels need direct sunlight to produce the electricity needed to power your home. The portions of your roof where solar will be installed should be free of shade for most of the day to prevent reduced production.
What causes shading on roofs? Trees are the most obvious culprit, but shade can also be cast by your chimney, dormers, or HVAC vents. Your installer can use a tool called the “solar pathfinder” to determine whether these nearby objects will cast shade on your panels.
Solar panels can be installed on almost any kind of roof material and almost any roof structure, whether it’s flat or pitched. Your roof’s material will make a difference in what kind of racking system should be installed. A racking system is the apparatus that attaches the panels to your roof. Your installer will recommend the right racking system for your particular roof.
Solar panels require a sturdy, reliable surface. If your roof is more than 10 or 15 years old, you may want to consider replacing it before installing solar panels. Ask your installer for insight.
If you decide to replace your roof before installing solar panels, be sure to choose a long-lasting material. You want your roof to last as long as your solar system, which is typically a minimum of 25 years.
What if my roof won’t work for solar panels?
Whether due to shading, obstructions, or orientation, you may find that your roof isn’t suitable for solar panels. If rooftop solar won’t work, you may want to consider a ground-mounted system instead.
If you have enough ground space away from shadow-casting trees and other objects, a ground-mounted solar array might be a great option.
If neither a rooftop nor ground-mounted system will work, you may still be able to benefit from solar energy. Depending on your area, you may be able to purchase solar electricity from a community solar array.
What if I live in a historic district or HOA?
If you live in a historic district, some extra steps may be required during the permitting process. Your installer should know about these and handle them on your behalf. They’ll need to ensure that the installation complies with local historic requirements. Any costs for this extra permitting should be included in your solar contract.
Homeowners associations (HOAs) can be a bit trickier, though not always. While we’ve come a long way overall, some HOAs still seek to deny their members the right to install solar panels on their homes. Others place restrictions on how and where solar can be installed. Thankfully, many states have passed laws to protect homeowners’ solar rights. See if your state has protections in place by visiting the Database of State Incentives for Renewables & Efficiency. Use the site’s policy search tool and use the keywords “easement” or “access”.
If you need help navigating the process or changing your HOA’s policies to be more solar-friendly, check out our free HOA Solar Action Guide.
Deciding if your roof is a good fit for solar panels is just one part of going solar. For more information about how rooftop solar works, ways to pay for it, and what to expect from the purchase and installation process, download our free Go Solar Guide.