What is the standard size of a solar panel?
Here’s a guide to understanding the standard dimensions of solar panels.
Solar panels come in all kinds of different sizes, from foldable panels you can take camping to large panels that are deployed in megawatt-sized solar farms.
There are even little ones that you can fit in a backpack to keep your phone or laptop charged.
This article will focus on solar panels for homes, because a homeowner will often want to know how many solar panels will fit on their roof or in their backyard.
Solar panel cell counts don’t matter as much anymore
I wanted to start off by mentioning that solar panel cell counts, which in the past was used to distinguish between panels aimed at residential and commercial use, are less meaningful than they used to be.
A few years ago, it used to be typical that 60-cell solar panels were known as residential panels and larger 72-cell solar panels were for commercial use. This was true when solar panels were nearly always made of individual cells that were 6 inches square.
While many residential panels still have 60-cell counts, a variety of new technologies and manufacturing techniques mean that you can’t rely on cell counts to tell you the size of solar panel. For example, half-cut solar cells, which doubles the cell count in a panel, are used by many manufacturers.
Meanwhile, SunPower uses different cell sizes and spacings, resulting in panels that may have 66 or 96 cells in residential-sized panels.
Finally, some manufacturers, such as Solaria and JinkoSolar, use cells that are cut differently and mounted on a panel as ribbons. This minimizes the gap between cells and results in cell counts that are different from the conventional 60 and 72-cell sizes.
The difference between residential and commercial solar panels
Most solar panel manufacturers categorize their panels as residential and commercial. In most cases, there is no difference in technology between the two. Commercial panels are simply larger.
The reason that residential panels are smaller is because the installation crews for residential projects are smaller and less heavy equipment may be available to them. Often the panels are manually carried up to the roof on a ladder by a crew member, making the size and weight of a single panel an important consideration.
Commercial projects, on the other hand, will have larger crews and equipment such as boom lifts to assist with moving panels into place.
However, there’s no rule that residential projects can only use residential panels. Some installers will use commercial panels on homes, depending on the size and shape of the roof. If your home has a larger roof and you have a lot with enough space to allow a boom lift to maneuver, your solar installer might use commercial panels. The advantage of larger panels is that they can help cut down installation time because of fewer parts to install. If your project uses microinverters or power optimizers, a commercial sized panel can save you money by reducing the number of inverter components needed.
Sizes of residential solar panels
While they generally fall within a similar range, there is no standard length and width for residential solar panels. You can see in the table below of selected panels that they can vary in length by almost 10 inches and in width by nearly 7. However, you will find that they commonly weigh under 50 pounds to conform with the OSHA lifting weight limit guideline for one person.
In the past, you could count on residential solar panels being about 40 inches wide by 65 inches long, give or take a few inches. However, this is no longer true. Panel sizes started creeping up as manufacturers released 400 watt solar panels. These higher power panels now hover around 70 inches in length, with some panels, like the SunPower M-Series, measuring 74 inches in length. That’s as long as older generation commercial solar panels.
Here’s a table with a selection of some popular residential solar panels.
| Solar panel model | Power (watts) | Length (in.) | Width (in.) | Height (in.) | Weight (lbs.) |
|---|---|---|---|---|---|
| QCells Q.PEAK DUO BLK ML-G10+ | 410 | 74.0 | 41.1 | 1.26 | 48.5 |
| SunPower SPR-M440-H-AC | 440 | 73.7 | 40.6 | 1.3 | 48 |
| Solaria PowerXT-400R PM | 400 | 64.7 | 47.4 | 1.6 | 46 |
| REC Alpha 430 Pure-R | 430 | 68.1 | 44.0 | 1.2 | 47.4 |
| Panasonic EVPV350PK | 350 | 69.1 | 40.9 | 1.2 | 43.0 |
| Panasonic EVPV410H | 410 | 71.7 | 40.0 | 1.2 | 45.0 |
| Canadian Solar HiKu6 | 420 | 67.8 | 44.6 | 1.18 | 47.0 |
| Silfab SIL-410 BG | 410 | 73.4 | 40.5 | 1.4 | 45.8 |
Sizes of commercial solar panels
While it’s less frequent that solar installers will use commercial-sized panels for residential projects, the larger size can be useful with some system designs. It’s also possible to save money money if you are using a microinverter or power optimizer based system
For comparison with the residential panels above, here are a few commercial sized panels on the market.
| Solar panel model | Power (watts) | Length (in.) | Width (in.) | Height (in.) | Weight (lbs.) |
|---|---|---|---|---|---|
| QCells Q.PEAK DUO XL-G10 | 490 | 87.2 | 39.4 | 1.38 | 64.2 |
| Canadian Solar HiKu6 | 555 | 89.7 | 44.6 | 1.18 | 60.8 |
| JinkoSolar Eagle 72HM G2 | 415 | 87.2 | 39.4 | 1.38 | 64.2 |
| Trina Solar Tallmax | 490 | 91.1 | 40 | 1.38 | 57.3 |
As you can see, these widths are in the same range as residential panels, but they are roughly 20 inches longer. They also exceed 50 pounds and require two people to lift to meet OSHA guidelines.
What is the size of an individual solar cell?
When it comes to traditional solar cells that aren’t half-cut or shingled, the most common sizes are:
- 125mm x 125mm (5 inch)
- 156mm x 156mm (6 inch)
Most solar manufacturers are using 6 inch cells, with one notable exception being SunPower. For example, the 96 cell SunPower panels use smaller 5 inch cells, which explains why their panels are similar in size as 60 cell panels from other companies.
Half-cut cells means that these cells are literally cut in two, reducing the size of the cells by half and doubling the number of cells in a panel. Shingled or ribbon-type cells used by some manufacturers cut solar cells in different ways still and eliminate the gaps between cells that are found in conventional panels.
How many solar panels will fit on your roof?
As you can see, there is quite a bit of variability in the size of solar panels. If you want to know the exact number of panels you can fit on your roof, you’ll need to take some measurements and also understand if you have fire setback rules in your city. If you do, you might not be able to place solar panels within 3 feet of at least one of the edges of your roof, reducing the amount of space you have available.
I wrote an article about how to know how many solar panels will fit on your roof that might be helpful. In any case, the average size of home solar systems is now about 7 kilowatts. If you’re using 400 watt panels, that translates to 18 panels.
That’s a big change since I installed my 18 panel system in 2013. It has a rated output of only 4.6 kW, reflecting the improvement in panel efficiency and larger panel sizes in the past 10 years.
