How Much Do Solar Panels Weigh?
4 - Minute Read
Jan 11, 2023
Solar panels add weight to roofs. How much do solar panels weigh and how much does this number factor into whether your home is good for solar? Let’s examine the facts so you and your installer can determine whether your roof can handle a solar array.
How Heavy Are Solar Panels?
Solar panels come in multiple sizes, with a varying number of solar cells and in a range of wattages that make it hard to say exactly how much solar panels weigh. However, we can think about the total solar energy system weight, including the panels and racking equipment, to get a ballpark number. Racking is the metal framework a solar installer will need to add to your roof to hold the solar panels.
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Solar Panel System Weight: What You Should Know
Let’s explore different types of solar panels to see how much weight a photovoltaic (PV) array might add to your roof.
How Monocrystalline, Polycrystalline And Thin-Film Solar Panels Affect PV System Weight
On an individual basis, monocrystalline and polycrystalline modules might not differ much in weight. But the solar module type you choose can impact how much your system weighs. The more efficient monocrystalline module can allow you to use fewer panels, potentially saving some pounds. How much you can save on system weight depends on the amount of power output you need, though. Consult your installer to determine the best system size for your energy needs.
Residential Solar Panel Size And Weight: Rule Of Thumb
Even though solar panels come in numerous sizes, 60-cell and 72-cell panels are common in PV systems. Each cell is about 36 square inches.
If you need a 6-kilowatt (kW) solar power system to meet your energy needs, you may require 16 – 22 panels.
So how much area will they occupy on your roof?
Using 60-cell panels, you may need a system that takes up to 330 square feet on your roof. With 72-cell panels, the array might require no more than 288 square feet. 72-cell panels are more often used in commercial solar panel applications.
As for the weight of a solar cell, it’s approximately .67 pounds. Using the example of a 6-kW system with both 16 panels and one with 22 panels (60 cells each) the weight of the panels alone would range from 643 – 884 pounds.
Factoring In The Solar Racking Weight
As mentioned, solar installers also need to add metal mounting equipment known as racking to your home’s roof. This tacks about 1.33 pounds per square foot onto the project weight. One square foot of solar panels adds an extra 2.17 pounds, so a complete PV array that includes panels and mounting hardware weighs about 3.5 pounds per square foot.
Everything considered, the total weight for a system using 60-cell panels and one using 72-cell panels would be approximately 1,154 – 1,323 pounds.
Can Roofs Handle The Weight Of Solar Panels?
The average roof can handle approximately 20 pounds of weight per square foot, meaning the average solar panel system is well under the limit and unlikely to damage your roof.
As a comparison, snow can range from 3 pounds per square foot for fresh, dry snow to nearly 20 pounds for wet snow.
Melting snow on solar panels can slide off a roof easily, preventing snow buildup on your roof. This also helps keep solar panels clean.
How Much Do Solar Shingles Weigh?
Solar shingles from brands like Tesla weigh approximately 13 – 20 pounds per square foot. Remember, though, that they also function as roof coverings, which are typically materials ranging in weight from 2.5 pounds for asphalt shingles to 19 pounds for tile.
Solar shingles are often less efficient than conventional panels, so the system would have to be larger to produce the same amount of energy. Solar shingle systems are typically also more expensive.
FAQs: Solar Panel System Weight
Here are a few questions about the average weight of solar energy systems.
How much do residential solar panels weigh?
Solar panels vary in the number of cells they have, making it difficult to assign an exact weight to them. That said, 40 pounds per 60-cell module is a good estimate for residential solar panels from companies like Qcells. This doesn’t include racking equipment, however.
Can my roof support solar panels?
This depends on the condition of your roof. A roof in good condition should be able to withstand 20 pounds of weight per square foot, but your roof may be older and not in the best shape. Check with a qualified roofing contractor or solar installation company to verify that your roof can handle the weight of the panels.
Are inverters and batteries included in the solar system weight?
String inverters and batteries are typically mounted on a wall, so they shouldn’t be included in the system weight. Panel-mounted micro inverters will add less than 2.5 pounds to the weight of each solar panel.
The Bottom Line: Don’t Let Solar Panel Weight Make You Wait
Weight is seldom an obstacle for homeowners ready to start generating renewable energy – even if your roof is getting old. That just means it’s a good time to consider the best roofs for solar panels.