Solar Panels Size & Weight (Including Commercial Dimensions)
Sharon Lee • Updated on February 20, 2023 • [rt_reading_time postfix=”minute”] read
Sharon Lee • Updated on February 20, 2023 • [rt_reading_time postfix=”minute”] read
Solar adoption has been gaining momentum in recent years thanks in part to decreasing costs, increasing concerns around climate change, and the need for businesses to reduce their carbon footprint. In 2020, the International Energy Agency (IEA) declared solar power to be the cheapest energy source available and now the option to lower operating costs by using a cheaper form of energy has made solar accessible to businesses of all sizes.
If you’re exploring solar for your business, it’s important to know that the industry has two main sectors – commercial and residential. While the concept of capturing energy from the sun is the same for both, there are some differences in commercial and residential solar technology. Things like solar panel size, wattage, efficiencies, and the way the panels themselves are manufactured vary based on the end application.
Here’s an overview of some of the primary differences between commercial and residential solar panels.
Before we get into things like solar panel size and weight, let’s first talk about the materials used to make solar panels. There are three types of solar panels on the market today.
Monocrystalline solar panels are the top of the line, provide the highest efficiency, and are generally considered to have the best look to them. They’re also typically the most expensive option because of the way they’re made – a single pure crystal of silicon is inserted into molten silicon and slowly extracted.
Polycrystalline solar panels are less expensive because they’re made from silicon crystal fragments rather a single crystal. The downside is that they aren’t as efficient or as powerful as monocrystalline panels. A typical monocrystalline panel can achieve 20 to 23% efficiency and generate 300 to 550 watts of power, while polycrystalline panels are only 15 to 17% efficient and produce 300 to 400 watts of power.
Thin film solar panels are lightweight and flexible, and while they offer the lowest efficiency of the three (6 to 15%), they are great for certain installations where the roof may not be able to accommodate the larger, heavier panels. Unlike the other two types of panels, thin film panels are typically made with cadmium telluride (CdTe), not silicon wafers.
Check out this article to learn more about the different types of solar panels on the market.
To understand how big solar panels are, let’s first talk about the basic building block – the photovoltaic (PV) solar cell. We’ll focus on solar cells used for mono or polycrystalline panels, since those are most commonly used for commercial applications.
Individual PV solar cells are thin slices of silicon that typically measure 6 inches long by 6 inches wide. Multiple solar cells are assembled together to form a rectangular shaped panel.
The standard solar panel size typically contains either 60 or 72 cells. You can also find panels with as few as 32 solar cells on recreational vehicles, as well as some larger commercial panels with as many as 96 cells.
As for the actual footprint of the assembled panel, there are two key factors that impact solar panel size: the type of solar cell (monocrystalline, polycrystalline, or thin film) and the number of cells. The greater the number of cells, the longer the panel is.
This is where we start to get into the differences between commercial solar panels and those used in residential projects.
A single residential solar panel typically has 60 PV solar cells and measures 5.4 feet by 3.25 feet (65 inches long by 39 inches wide). The panels are between 1.5 to 2 inches deep. Most 60-cell residential solar panels produce around 300 watts of power each.
Commercial solar panels typically include 72 solar cells and measure up to 6 feet wide (78 inches long by 39 inches wide). As with residential solar panels, commercial models are between 1.5 to 2 inches deep. Most 72-cell commercial solar panels produce between 350 and 400 watts of power.
Once the panel is assembled it’s set into 2-inch metal frame, which adds to the overall size of the panel. Of note, while there are some adhesive thin-film panels that can be installed directly on your roof, most thin film models are put into the same metal frame as the others, as it improves the durability of the solar panel.
While the figures above represent the standard solar panel size (excluding the frame), it’s important to know that there are some variations by manufacturer. Also, monocrystalline panels tend to be slightly larger because they are designed to have slight gaps between the solar cells. There are no gaps between the cells in a polycrystalline solar panel.
Panel efficiency is the other factor at play here. You may see one manufacturer that offers a 72-cell commercial solar panel that produces 400 watts of power, while a competitor’s 72-cell panel produces slightly more or less power.
It used to be that if you needed each panel to produce more watts of power, you needed to add more PV cells. However, as photovoltaic cell technology has advanced in recent years, that old equation is falling by the wayside.
Today’s modern panels are much more efficient, which means that you can generate more power without increasing the actual footprint. For example, the newest generation of monocrystalline panels are about 5% more efficient than their predecessors.
This is why there’s often no difference in the physical size of a 400 watt and 500 watt solar panel – the solar panel size depends on the materials and the efficiency.
The other important consideration when talking about solar panel size is understanding how much solar panels weigh.
If you’re planning a rooftop mounted solar system, it’s critical that you understand how much your solar panels weigh, so that you can determine if your roof can support the system.
As with the size, the weight of a solar panel can vary by manufacturer. Typically, 60-cell residential solar panels weigh around 40 pounds a piece. The larger 72-cell panels used for commercial solar installations can weigh 50 pounds each or more.
The weight also varies based on the type of material used to make the solar panel, due in part to the manufacturing process. For example, a 365-watt monocrystalline solar panel could weigh 45 pounds whereas one made of polycrystalline cells would weigh 49 pounds.
Keep in mind that the weights above don’t include any of the mounting equipment, so that’s something else that you’ll need to consider when working with your solar provider.
If you need even more resilience than what’s provided by your solar panels, you may also want to include battery storage as a part of your overall solar energy plan.
Most solar storage systems use banks of lithium ion (Li-ion) batteries to store excess energy. The number of batteries needed will depend on the size of your system and your specific energy needs.
Thanks to technological advancements in recent years, the newest Li-ion batteries are safer, smaller, and increasingly more affordable than other types of batteries available on the market. They also have high energy storage capacity and can be recharged repeatedly.
The good news is that the weight of your energy storage system isn’t really a factor when it comes to roof-mounted arrays. Most solar battery systems are housed on the ground and connected to the solar system via wires.
Whether you’re installing solar panels on your home or you’re planning a commercial solar installation for your business, one panel won’t do the job – you’re going to need a solar array.
Solar panel systems are not one-size-fits-all, so it’s always best to work with a reputable commercial solar provider that will design, install and maintain a solar system that’s customized for your business. A company well versed in commercial solar panel installation will be able to expertly guide you in creating a system that can help you accomplish your specific energy goals.
Solar professionals, like those at Velo Solar, can help you select the correct solar panel size, calculate how many solar panels you’ll need, and ensure that your system will provide the solar power you need now while still being able to grow with you in the future.
Let’s bring this discussion into the real world with an example. If you’re looking to build out a 100 kW solar system and you want to use 400 watt panels, you’d need 250 panels. A common configuration for an array of this size might be 10 rows of 25 panels each. Using the average solar panel size of 6 feet by 3.25 feet, and assuming you leave minimal space between the panels, your rooftop solar system would measure roughly 4,875 square feet.
Now, let’s consider the weight of that system. At 50 pounds per panel, the array would weigh in at 12,500 pounds or a little over 2.5 pounds per square foot. Even with the added weight of the mounting hardware needed for a system of this size, most commercial buildings should be able to support the weight of your solar array.
That said, your solar provider may still recommend performing some due diligence and involving a structural engineer to ensure the roof can support the system your business needs.
In some cases, the cost savings of generating your own solar energy may still outweigh the cost of reinforcing your facility’s roof, but if it doesn’t, there are several other solar options you can consider, including a ground-mounted array or solar carports.
Let Velo Solar help your business lower its energy costs and its carbon footprint, while also giving you the peace of mind that a solar plus storage system provides during a grid outage.