As advancements are made in solar technology, solar panel manufacturers are able to offer thinner and more efficient solar panels that can withstand all types of weather conditions. This has led many homeowners to install these highly efficient and durable solar panels on their roofs.
While the roof of a building can be an excellent and discreet location for a solar panel array, not all roofs can accommodate solar panels properly.
To help you decide if your roof is a good candidate for solar panels, we are going to go over everything you need to know about assessing a rooftop for a permanent solar installation. On top of that, we will also go over some useful information relating to the proper installation of solar panels on a roof.
How Do I Know if Solar Panels Will Fit on My Roof?
The first question you need to ask yourself before you consider a roof-mounted solar array is whether or not your roof is even large enough for solar panels in the first place. While it is true that compact and foldable solar panels are now more accessible than ever before, most of these smaller types of solar panels are not designed for permanent outdoor installation on a rooftop.
While most roofs can accommodate at least some solar panels, if you are looking to install a large-scale system, you will need to install many solar panels, which means you will need a roof that offers plenty of unused square footage.
Even if your roof has plenty of space and can fit numerous solar panels, it will have to be free from obstructions. Vent pipes, chimneys, skylights, and rafter systems can all get in the way of solar panels.
Then, of course, the shape of your roof will also play an important role in determining how well it can accommodate solar panels. Ideally, you want a large, flat surface, rather than a curved and uneven roof.
Does the Open Area of Your Roof Get Enough Sunlight?
The amount of direct sunlight your roof receives on an average day is possibly the most important factor in determining whether or not it is right for solar panels. Since all types of solar panels rely on sunlight to generate electricity, it is vital that they are mounted in a sun-facing direction.
If, for example, the area of your roof where you chose to mount your solar panels was partially shaded by a large, overhanging tree, the production you would get out of your solar panels would be significantly reduced.
Solar Panel Productivity and Efficiency:
When we discuss solar panel production and efficiency, we are not talking about what power rating the solar panels have, instead, we are talking about how well they actually function based on several factors, most importantly, how much sunlight they are able to absorb.
This is why angle and direction are so critical when you are discussing any type of solar panel array. If the solar panels are not positioned properly, the entire solar power system will produce less electricity, regardless of the quality of your solar equipment.
As you would expect, you always want to position your solar panels in a way that they will have the highest productivity possible, meaning that they will be positioned in a way that they have the best opportunity to absorb as much sunlight as possible.
Choosing the Best Direction for Your Solar Panels:
Since direction and angle are so critical for solar panel placement, it is not enough to just have a large enough roof to accommodate your desired number of solar panels. You also need to have a roof that is properly angled in a sun-facing direction.
In the northern hemisphere, the general rule for solar panel placement is to have the transparent surface of the panels facing in a true south direction. This works best because south-facing solar panels will receive more direct sunlight throughout the day than solar panels that are facing any other direction. While solar panels facing in other directions can work, they are almost always less productive than solar panels that are facing directly south.
The Impact of Roof Pitch:
While direction is incredibly important, it is also worth considering the angle of your roof. Due to the tilt of the Earth, sunlight does not hit the ground from directly above. Depending on where you live and the day of the year, positioning your solar panels at a certain angle will ensure they are able to capture the optimal amount of sunlight.
For rooftops that are too steep, or have too shallow of a pitch, solar panel efficiency can be reduced. Ideally, you would have a roof that is angled somewhere between 33 and 45.
Avoid Any Shady Areas:
You probably guessed that you will want to avoid putting solar panels on a roof that is shaded. Large trees, nearby buildings, or anything else that casts a shadow over your roof during the day can significantly impact the performance level of a roof-mounted solar power system.
Determining whether or not your roof is shaded is actually fairly simple - just check for surrounding obstacles. If there is nothing near your home that is taller than your roof, there is very little chance you will have to concern yourself with shade. If, on the other hand, your home is surrounded by tall trees and other obstacles, keep an eye on the roof every hour for a full day, but remember, the angle of the sun in relation to your roof will change throughout the year. So, even if the area of your roof where you plan to position solar panels is not shady at any point on the day that you check, the situation can alter with the changing of the seasons.
So, What is the Ideal Roof Space for Solar Panels?
Under ideal circumstances, you would have a large and flat area of your roof that is perfectly south-facing, unobstructed by shade, and pitched at an angle of about 36.
If no section of your roof has these exact features, do not worry, it does not mean you cannot mount solar panels on your roof; instead, it just means that your roof is not perfect.
East and west-facing roofs can also work for solar panels, they just tend to receive roughly 85% of the light a south-facing roof is exposed to. Even a north-facing roof can work, but only if the roof is perfectly flat, as is common with industrial buildings and apartments.
The important thing is assessing all of the factors that make a good roof for solar panels and determining how far off your particular roof is from the ideal situation. Ask yourself, do you have a large enough unobstructed area on your roof that can accommodate enough solar panels to meet your power needs? Is there a south, east, or west section of your roof that is available? Is the section of your roof you have chosen unshaded? What does the angle of your roof look like?
If you have assessed your roof and everything seems reasonably close to the ideal, your roof is likely a good candidate for solar panels. If your roof is not up to the task, do not worry, many people choose to build angled frames for solar panels in their backyards. When installed correctly, these ground-mounted solar panels work just as well as those that are mounted on a rooftop.
Finding the Right Solar Panels
Whether you are looking to mount solar panels on your roof, or you have chosen to build a backyard solar array, we can help you find the perfect solar panels to build your solar power system.
This affordable and highly efficient 200 Watt Monocrystalline Solar Panel features a ‘plug-and-play’ junction box, a durable aluminium frame, and mono PERC technology. Quick connect MC4 cables allow you to use this panel on its own, or as part of a series, so it is ideal for both roof and ground-based solar arrays. As an added bonus, the panels come with 28” leg stands, so you can even position them directly on the ground without having to build an angled frame yourself.
If you are looking for a more powerful type of solar panel, we encourage you to read our 300 Watt Solar Panel Guide, which will explain everything you need to know about the output of 300W solar panels. It will also point you in the direction of some high-quality options that can be used to build your own solar array. Remember, if you have limited space on your roof, choosing solar panels with a higher power rating will let you make the most of that space.
Renogy Solar Equipment:
If you are on a budget, but would still like to purchase high-quality solar equipment, we recommend taking a look at our budget-friendly Renogy Solar Equipment Collection. We carry everything from high-efficiency Renogy solar panels, to Renogy’s high-capacity deep cycle solar batteries.
If you are not quite ready to commit to a full roof-mounted solar power system, you should consider a ready-made solar panel kit. These kits come with everything you need to get started, including solar panels, a charge controller, power inverter, solar battery, and all of the cables and connectors you need to start harnessing and using solar electricity.
This Lion Energy 400 Watt Beginner Solar Panel Kit is a great place to start and is available at a very reasonable price point. It comes with everything you need and will help you learn how to use solar power.
If you are looking for something more specific, our collection of Solar Kits from Renogy is very extensive. We carry everything from 100W kits, to much larger 1,200W kits. Not only are solar kits convenient, the bundling of equipment also means you get high-quality equipment at reduced prices.
Even if your roof cannot accommodate enough solar panels to meet your full energy needs, you can still reduce some of the cost of your monthly electricity bills by installing a smaller solar power system. Even a backyard system that consists of one or two solar panels can still reduce your dependence on the utility companies. On top of that, solar power is environmentally friendly, so you would be saving money while doing your part to protect the environment.
If you have any questions about roof-mounted solar panels, or any other questions about solar power, do not hesitate to reach out to us!