Solar Panels

How Big are Solar Panels? (Solar Panel Dimensions)

By:Michael Johns

solar panel size header

In this article, you will learn about solar panel dimensions. Plus you will find the answer to the question ‘How big are solar panels?’

A normal solar panel for a house measures 5.5 by 3.3 feet. 

That’s 18 square feet surface area per panel.

Now, those numbers might now mean much to you on their own, especially if you don’t know how big your roof space is…

And you probably aren’t able to quickly go and measure the square footage building.

Don’t worry, stick around, and together we’ll go through solar panel dimensions, what it all means, and how much power you can expect to generate.

How Big is a House Solar Panel?

The average residential solar panel is 66 by 40 inches (5.5 by 3.3 feet) and weighs 40 pounds. 

Solar panels for your house are made up of 60 solar cells. These cells are what absorb light and convert it into electricity. A solar cell has a standard size of 6 by 6 inches  (156mm by 156mm). A 60-cell panel is laid out in a 6×10 grid. 

To put the size into context a solar panel is as long as the average female is tall. And as wide as a single bed.

The surface area of a residential solar panel is around 18 square feet. With the average American home roof being 2500 square feet in size, you could theoretically fit 138 solar panels in that space. Although that’s not entirely practical for a number of reasons, more often a house will have 18 solar panels covering 350 square feet of roof.

solar panel dimensions diagram

How Much Space Do Solar Panels Need?

As you can imagine based on the dimensions of a solar panel, they need plenty of space, especially for bigger arrays.

The most common size home solar array is 18 solar panels which needs 350 square feet of roof space.

The beauty of solar panels is that you can use as few or as many as you need. In fact, outside of the residential market many people use various sized products on vehicles, sheds, and cabins. 

How Many Solar Panels to Run a House

If you’re wondering how much space you need for solar panels, you first need to calculate your energy requirements. This will tell you how many solar panels you need and the space they then require.

Let’s look at how you can tailor a solar panel system to your requirements.

  1. Work Out Daily kW Consumption

The first thing you need to do is work out how much energy you use each day. You can find the information on your utility bill. It will be marked as a total in kWh. Usually this is the total energy consumption per month. To work out the daily kWh simply divide the total by number of days.

Let’s say it’s 600kWh per month divided by 30 days:

600kWh ÷ 30 days = 20 kWh per day.

  1. Work Out Daily Wattage

Next we need to convert the kWh (Kilowatt hours) into Wh (Watt hours) per day. This will make it easier to work out the number of solar panels later.

1 kilowatt is equal to 1000 watts.

So just multiple the kWh by 1000 to get Wh.

20 kWh x 1000 = 20,000 Wh per day. 

  1. Divide by Peak Sun Hours

Solar panels produce the majority of their electricity during peak sun hours. This is when the sun is brightest during the middle of the day between 11am and 3pm. Around 4 hours per day. 

You need to generate your solar electricity needs during these hours. To work out how much electrcity your solar panels must provide in these hours divide the daily Wh by peak sun hours.

For example, 20,000 Wh ÷ 4 Hours = 5000 Watts.

Now we know we need a system power of 5000 Watts.

Peak sun hours vary depending on where you live, you can use these NREL maps to help you find your local data.

  1. Number of Solar Panels Required

Now we know the total power requirements of a solar panel system, we can work out how many panels you will need. 

To do this divide the Total Watts by Individual Panel Watts.

The average residential solar panel is 250 watts.

In our example it is 5000 Total Watts ÷ 250 Watts = 20 solar panels.

You will need about 20 solar panels to run a house.

20 solar panels on a shingle roof house
A house with 20 solar panels

Are Bigger Solar Panels More Efficient?

No, bigger solar panels are not more efficient but they will deliver more power. For example, the more solar cells a panel has then the more electricity it will produce. For example, a home solar panel is 60 cells and around 250 watts. But you can also get smaller 50 watt, 100 watt, and 200 watt panels.

In addition, commercial installations usually use bigger solar panels consisting of 72 cells.

When it comes to efficiency it’s all about the technology and components used to create the solar panel. The number 1 factor in deciding the efficiency of a solar panel is the cell structure. The solar cells are made from silicon semiconductors. The quality of this silicon dictates efficiency. The most efficient solar cells are called monocrystalline. But you can also get cheaper cells known as polycrystalline which are slightly less efficient.  

Efficiency is important when it comes to the size of a solar panel. Simply put, the more efficiency the higher the power. So if you had a monocrystalline and polycrystalline solar panels of the same size, the monocrystalline would have a higher wattage output

How Big is a Commercial Solar Panel?

Commercial solar panels tend to be much bigger than residential products. This is because they are required to generate more power and there is usually ample space for the installation. 

Afterall, commercial buildings are bigger and require more energy than your home.

commercial solar panels
Larger Commercial Panels

The average commercial solar panel is made up of 72 cells (still 6 x 6 inches) and measures 6.5 feet by 3.3 feet wide. That’s 78 by 39 inches. And over 21 square feet.

As you can see they are generally the same width but much longer than residential solar panels. The extra 12 cells are added to the length as they are laid out in a 6 x 12 grid.

This increased size adds to the weight taking it up to around 60 pounds.

All of this means one thing though, added power of between 350 – 400 watts.

Adding to this, new manufacturing techniques are allowing the panels to grow in size to 98 cells and over 500 watts!

Solar Panel Size and Power Comparison Chart

Here’s a useful comparison table to show how big common sizes of solar panels are:

Solar Panel WattageAverage Dimensions (Inches)
50 Watt23” x 20”
100 Watt39” x 26”
150 Watt49” x 27”
200 Watt59” x 27”
60 cell residential 250 Watt66” x 40”
72 cell commercial 350 Watt78” x 39”

How Much Do Solar Panels Weigh?

When looking at the size of solar panels you should also consider the weight. You will need to ensure the roof structure you are mounting them on can support the array. Different types of roofs may have limits on what they can support.

You will find the average residential solar panel weighs 40 pounds, while a commercial one is nearer to 60 pounds. For more information read my article on Solar Panel Weight.

Final Words on Solar Panel Size

As you can see, solar panels are not small. If you want a decent amount of power or enough to power a whole house then you’re going to need plenty of space.

It’s not always possible to completely power a house from solar panels as they are simply too big to fit on a rooftop. While you might have ample space, you also need to take into account orientation, pitch, and shading into the available square footage. For example, you’ll not be generating electricity efficiently with North facing solar panels

But don’t worry, even if you don’t have a spare 300 square feet, you should be able to find enough space to accommodate enough solar panels to make a difference.