When it comes to the weight of solar panels and solar panel sizes, you will find there isn’t a huge variation between the different brands. More important than the weight of any specific solar panel is the total weight of the installation, and the impact it will have on your rooftop.
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Since solar panels are mounted outdoors, they must be built strong enough to withstand all types of weather conditions.
When it comes to the exact weight of solar panels you will find that it varies between different solar panel manufacturers and models, and whether you are using polycrystalline, monocrystalline, or thin-film solar panels.
The average weight for a residential solar panel is around 40 pounds. They are approximately 5.4 feet long and 3.25 feet wide, which works out to about 2.3 pounds of weight per square foot. Each module typically contains 60 solar cells.
Commercial solar panels are slightly larger than residential solar panels. They are generally around the 50-pound mark and measure in at around 6.5 feet long and 3.5 feet wide. Each module usually contains 72 solar cells but can go up to 98 cells.
Even with the extra weight, the commercial solar panels only have a weight of 2.5 pounds per square foot, given that the weight is spread over a larger area.
Typically, either 60-cell or 72-cell solar panels are used for residential solar installations, but only 72-cell panels will be used on commercial installations.
Solar cells - the part of the solar panel which generates electricity - are relatively light, weighing only a few hundred grams each. The majority of the weight of the panel actually comes from the aluminum framing and tempered glass used to construct the solar panel.
While tempered glass is heavier than normal glass, it is the industry standard for solar panels. It needs to be able to withstand the impact of a 1-inch diameter hail-stone traveling at 50 miles per hour.
An example of solar panels mounted on a roof.
When you are installing rooftop solar you must make sure your roof is in good condition and can take the weight of the installation.
Solar panel weight on your roof
If you were installing a 6 kilowatt solar array made of 20 panels, the panels alone will weigh in at approximately 800 pounds. The total area covered would be around 352 square feet. This works out to around 2.3 pounds per square foot on a sloped roof and about 5 pounds on a flat roof.
When you take into account the solar panels and all the mounting equipment, racking, junction boxes, and wiring, the total weight of the solar installation comes in at around 3-4 pounds per square foot (this does not include the inverter, which usually gets bolted to the wall). This is the equivalent of a pair of work boots or a half-gallon bottle of milk.
Most roofs can easily handle the weight
The vast majority of the time, your roof will be able to handle the additional weight of an average solar panel installation. According to the Insurance Institute for Business & Home Safety (IBHS), your roof shouldn't have any issues as it has been designed to withstand up to 20 pounds of snow per square foot before the roof becomes stressed. So 3-4 pounds of extra weight from the solar panels will not make much of a difference.
And what about the extra weight of snow that collects on top of your solar panels? Well, the good news is that not only can your roof manage the additional weight, the Office of Energy Efficiency & Renewable Energy says that snow can actually help to clean your solar panels (and rain does the same thing).
But make sure to get your roof checked if you have doubts
If you own a home with an older roof or are concerned that your roof won’t handle the extra weight, speak with a roofing company about having an inspection done by a structural engineer. This can help you determine whether or not your roof is up to the task of supporting the additional weight of the panels, and not voiding your warranty if something was to go wrong with your roof which would damage your photovoltaic panels or mounting hardware.
If your home is suitable for solar energy, it's one of the best ways to save money on your electric bill.
For homeowners in many states, it's possible to install a solar panel system that can offset 100% of your electric bills.
Solar panels have gone up in efficiency and down in price. Incentives and rebates are readily available, and financing a solar installation is more doable than ever before.
Check out our solar calculator to see how much it will cost you to install a solar panel system, and how much money you can save.
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