Solar panel size is primarily measured in two ways: physical dimensions and wattage capacity.
Although these measurements are separate, they are also somewhat related, as physically larger solar panels often have more room for additional solar cells, leading to higher wattages.
In this article, we analyze the relationship between solar panel size and wattage to help you make the best renewable energy purchasing decisions for your home.
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Solar Panel Size vs. Solar Panel Wattage
When searching for different “solar panel sizes” online, you may find that your product choices are typically differentiated by their wattage, rather than their physical dimensions. On equipment websites, the solar panels may be sorted by wattage groups, instead of sizes like small, medium, and large.
A solar panel’s wattage or “power capacity” refers to its energy generation potential, with higher wattage panels able to deliver larger amounts of solar electricity. Solar panel wattage is abbreviated simply with a “W'' and 1,000W is equal to one kilowatt (kW).
Common Solar Panel Wattages on Homes Today
In 2024, high-quality residential solar installations in the US typically utilize solar panels that are rated between 250W and 400W in power capacity. While lower-wattage solar panels (below 250W) may work for small, off-grid systems, higher-wattage solar panels (above 400W) are better suited for commercial or utility installations with fewer space restraints than residential rooftops.
Strung together and wired into your home’s electrical system, solar panel wattages are added together to create your total solar installation capacity. So if you install 20 solar panels, each rated at 325W, your total solar panel wattage would be 6,500W or 6.5 kW.
Common Solar Panel Sizes and Wattages
While there are no “standard” sizes, most of today’s premium home solar panels come in one of three primary formats, classified by the number of solar cells.
- 60-Cell Solar Panels: 60-cell modules are the smallest sized residential solar panels, and today’s products have average dimensions of roughly 5.4 feet tall by 3.25 feet wide. Great for fitting on complicated roofs with limited installation space, most 60-cell solar panels are rated under 325W in power capacity.
- 72-Cell Solar Panels: With two extra rows of cells, 72-cell solar panels are about 6.4 feet tall on average (while still 3.25 feet wide) and typically rated 350W or higher. 72-cell solar panels are ideal for residential roofs with ample installation area.
- 96-Cell Solar Panels: Rarely used for residential installations, 96-cell solar panels usually measure around 6.4 feet by 4.3 feet. Commercial 96-cell solar panels may be rated from anywhere between 300W to 450W and higher.Solar Panels with Half-Cut Cells, Wattage and Size
In the fast-moving world of renewable energy technology, half-cut solar cells are at the forefront of innovation in 2024, with several new products now available from today’s top manufacturers. Made up of solar cells that are “cut in half,” panels with this technology have increased power potential without larger installation footprints.
Doubling the number of solar cells per panel, half-cut modules typically contain 120 or 144 half-cut cells, with the same physical dimensions as a 60 or 72-cell panel. As a new product, solar panels with half-cut cells may not be available in all markets and are usually more expensive than traditional 60 and 72-cell panels.
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Total System Dimensions for Solar Panels
For efficient electricity production and ease of installation, nearly every home solar energy system is installed with the same panel wattage (and model) throughout. Knowing this, calculating the dimensions of a solar panel array is fairly straightforward: simply the sum of the panels’ dimensions as they are arranged and installed on your roof.
To illustrate how much roof space is needed for solar panels, let’s say that you decide to install a 9.6kW system to offset your home’s electricity use. This capacity can be created with two dozen 72-cell 400W solar panels, covering about 21 square feet each. In this scenario, you would need roughly 500 square feet of installation space (21 square feet x 24 panels) to host your system.
How to Choose the Right Solar Panel Size
Unless you are planning a DIY solar panel installation, more often than not, you will not have to worry about choosing the right solar panel size for your home. Instead, a professional solar installer (like Palmetto) can work with you to determine the best solar panel wattage and size for your roof or property, curtailed specifically to your unique energy demand, electricity costs, and available installation space.
Talk to an expert today about your home solar installation.
Palmetto experts are always available to answer your questions about solar panel wattage or any related topics. To learn more, please contact a Palmetto Solar Advisor today or explore further reading in our homeowner resource library.
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Brian is a writer, NABCEP PV associate and outdoor enthusiast living in Denver, Colorado. As a freelancer, Brian has written hundreds of articles to help individuals, businesses and our planet benefit from solar power and sustainable energy systems.