Solar Panel Weight
How much do solar panels weigh?
Each panel weighs around 42 pounds (19 kg), though this may vary from brand to brand, but is usually about the same for most solar panels used in home installations. Most residential solar panels have standard dimensions of 66 inches (1.65 meters) by 40 inches (1 meter) and 1.25 by 1.6 inches on the frame. This size makes them good for rooftop home installations, since you will need something between 20 and 28 solar panels most likely to be completely energy-independent.
Residential solar panels are normally about 5 and a half feet long (1.65 meters) and just over 3 feet in width (.9 meters). Commercial solar panels are often bigger, at about 6 and a half feet (1.9 meters) and can often weigh 50 or more pounds (22.7 kg). This of course can vary depending on manufacturer and how the panel is made. Also keep in mind the bigger the surface of your solar panels, the more production you can expect.
Commercial solar panels are typically larger than residential solar panels because most residential panels are made up of 60 solar cells while standard commercial cells have 72, and some can up to 98 or more cells.
Solar Panel Types
Just like anything else in life, solar panels come in different varieties, some of which may fit your home better than others. Here’s a quick summary of the different types of panels:
Photovoltaic Panels- These “thin film” panels are the most popular panels used in residential installations. They weigh approximately 40 pounds, though some can be as light as 33 pounds while others may weigh as much as 50.
Monocrystalline Panels- These panels are a little more robust at an average of 50 pounds each, and are most commonly used for commercial installations due to their size. Their energy output is greater than that of photovoltaic panels, so if you have a newer home you might consider using these types of panels to increase your energy output.
Polycrystalline Panels- One of the newest kinds of panels on the market, polycrystalline panels have made major advancements in recent years and are now the cheapest type of panels generally available, making them more popular in recent years for home installations. They weigh around 42 pounds each, and though they aren’t as efficient as other types of panels, their lower cost can compensate for their loss in output. Their efficiency has continued to improve in recent years however, and in some cases it is comparable to that of monocrystalline panels, making them more popular than ever.
Average solar panels measure about 65 inches (1.65 meters) by 39 inches (.9 meters), so how does work into a full size rooftop system of solar panels?
An average system size of 6 kilowatts will require 20 solar panels, which will take up approximately 352 square feet (107 meters) or about 27 feet wide by 13 feet long. This measurement presumes your panels can be placed very close together and your roof has no major obstructions, so the reality is that you’ll need a little more space than this to account for things like ventilation vents, chimneys, etc. Every roof is unique, and therefore every solar panel system will have to be arranged and oriented differently. One thing to remember, however, is the more compact your solar arrangement is, the cheaper it’s going to be.
Will Solar Panels Damage my Roof?
When properly installed, solar panels will not cause any damage to your roof whatsoever. Over the years a number of techniques have been developed to install solar panels safely, and none of them involve causing lasting damage to rooftops.
Can your roof support solar panels?
Knowing what we now know about the size and weight of solar panels, we can make a calculation of roughly how much a solar panel system is going to weigh, and whether or not your roof can support that kind of weight.
Given a standard 6 kilowatt installation (20 solar panels), the panels by themselves will weigh around 800 pounds (about 363 kg). According to our previous calculation, we know the system covers approximately 352 square feet, meaning we are looking at around 2.3 pounds per square foot. When you factor in incidental weight from mounting hardware and wiring etc, the weight supported will come out to something like 3-4 pounds per square foot.
Obviously, most roofs are going to be able to support substantially more weight than 3 or 4 pounds per square foot- how many roofers have you seen that exerted less than 3-4 pounds of pressure per square foot? Modern roofs are designed to support up to 20 pounds per square foot in most cases. However, if you’re still concerned that your roof may not be able to support the weight, a standard roof inspection can help you decide for certain if your roof can handle solar panels. Most roofing companies will do a normal roof inspection for a small fee, and most solar installations companies will perform an inspection before beginning an installation. Your installation company could insist on a roof reconstruction before beginning an installation if they find the roof to be in need of major repair.
So what have we learned? First off, the average solar panel is somewhere in the neighborhood of 40-50 pounds. Secondly, these panels are going to end up exerting something like 4 pounds per square foot of weight on your roof. We now know that most modern roofs are designed to support 20 or more pounds of weight per square foot, meaning solar panels can easily be supported by a modern roof in good condition. If you have questions about the condition of your roof, you can easily get a roof inspection by a private roofing company or your solar installation company will do it for you before beginning an installation. Furthermore, if your concern is that solar panels will damage your roof, then once again we put that fear to rest as there are numerous techniques for installing solar panels on a rooftop, and your solar company will choose the one that works best for your home needs and won’t damage your roof.