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How Many Solar Panels Can I Fit on My Roof

How Many Solar Panels Can I Fit on My Roof

Short on Time? Here’s The Article Summary

The article discusses the factors to consider when determining how many solar panels can fit on a roof. It highlights that roof size is a crucial factor and explains that before installation, the roof is checked for usable space, shading, and other issues. It also mentions considering energy needs, system type, brand, model, and size for the best return on investment. The article provides an example calculation, stating that the average home needs between 28 to 34 solar panels to power the entire home, based on the national average energy consumption.

It discusses the size, weight, and power generation of solar panels, noting that the number of panels should be determined based on energy needs rather than maximum roof capacity. Additionally, it mentions considerations for roof pitch, orientation, and energy output based on location and weather. The article concludes that going solar is an energy-efficient and cost-effective way to reduce utility bills.


Getting invested in solar energy is a decision that needs all kinds of preparation. Costs, size, brand, and efficiency of your panels are all factors that need consideration. 

At some point, you might’ve even asked yourself how many solar panels can you fit on your roof, right?

Roof size is probably the biggest deciding factor in determining the number of panels you’re able to install. In this article, we’ll be going over everything you need to know.

How Many Solar Panels Will Fit on My Roof?

Things to Consider

Installing solar panels on your roof is a great way to save money on your bills and be more eco-friendly. However, we’ll have to figure out what the best roof for solar panels is before we can install anything.

What typically happens before any solar panels are installed is that your roof is checked; usable space, shading, and other roofing issues are taken into consideration. 

how many solar panels will fit on my roof

You also have a few things to consider before having solar panels installed. Things like how much energy you need and the kind of system you want to use. 

Important information about the solar system like the brand, model, size, and quantity also needs to be considered. The right setup guarantees the best return on your investment.

How Many Solar Panels Do I Need?

This is equally as important. Figuring out the size of the solar system you need is a huge factor when it comes to determining how many solar panels you’re going to install. 

Not only does this sort of calculation involve roof size but also what kind of budget you’re working with. Depending on the size and type of system, it can involve different costs and physical requisites. 

By using the national average of 11,000 kWh of electricity use per household per year and taking 250W solar panels, the number of solar panels that the average home will need is going to be between 28 to 34. That should be enough to provide power to the entire home.

Solar Panel Size

The average size for a solar panel is around 65 in. by 39 in. when we look at residential solar installations. Each panel weighs about 40 lbs or so. 

Commercial panels are slightly bigger because they’re used for larger buildings that need a lot more power and are able to accommodate the size of the solar panels. 

Compared to commercial panels, residential ones are smaller in size and lighter in weight because they are designed for the roof of someone’s home. That kind of roof needs to be able to support the weight and size of the panels.

Do solar panels damage your roof, though? Not necessarily, your roof just needs to be able to support them, and so long as you don’t use commercial panels your roof is safe.

Solar Power Generation

A panel usually has close to 60 solar cells built into it. These cells are what convert sunlight into electricity. 

How Many Solar Panels am I allowed to Fit on My Roof

The solar panel inverter, that’s part of the solar system, directs the electricity and changes it into alternating current which is the kind of electricity you need to power most of your appliances.

Standard solar panels generate anywhere between 230 and 270 watts of energy.

However, that doesn’t mean that your roof is capable of fitting that many solar panels, even though it’ll cover all of your energy consumption. 

Let’s say the size of your roof is about 390 sq. ft. and a standard-sized solar panel is 18 sq. ft., which means you can fit around 20 or so solar panels onto your roof. 

We know that this number of solar panels might not be able to cover 100% of your energy consumption but that’s perfectly normal. Almost all of the houses that use a solar-powered system are still connected to the grid.

When there’s not enough power being generated from the solar panels, you can always draw some power from the grid to provide power to your home. 

Having this kind of setup means you only have to pay for the small amount of power you use from the grid. You won’t have to fully rely on the grid to power your home, so you’ll definitely be saving a good chunk of your money.

A perk about having a solar system installed is that when you produce more solar energy than you can use in a day, the extra power is given back to the grid. 

This means the utility company will give you credit for putting energy back into the grid. Usually, it’s in the form of utility bill credits which you can then use when your solar system is under the weather.  

The Size of the Roof

The size of your roof is a major factor that determines just how many solar panels you can have installed. 

how many solar panels can fit on my roof

You can start with the maximum number of solar panels your roof can physically support but it’s better to consider what your energy needs are. 

You want a return on your investment, and precisely calculating your energy needs helps to accomplish that.


Some might be concerned as to what the best roof pitch for solar panels is

Some people think that installing their solar panels on a flat roof is the way to go, but this isn’t actually the case. When your solar system is being installed it should ideally be angled at 40° and have no shade whatsoever. 

If it’s not possible then you should think of other ways that’ll maximize your solar energy, like going with solar panels that are more energy efficient.


It’s important to remember that you should only measure the areas of your roof that would be able to accommodate solar panels. 

For example, if the southwestern side of your home gets more sun than the other parts, then you only have to measure out that area. Measure the length of the northern side of the roof and then the eastern part from the corner where the roof ends.

Generally, it’s safer to measure along the walls of your home, even though it might not be as accurate. However, if you can get onto your roof safely then you can do so by all means. Getting on top of the roof will be a lot more accurate than measuring along the walls.

How Much Solar Power Can My Roof Generate?

The answer to this involves a few factors, in particular your location and the time of the year. 

Living in a state where there’s a lot of sunshine like Arizona means that a lot more energy can be produced by your solar panels. Someone living in Seattle might not be so lucky. 

how many solar panels can you fit on your roof

The time of year also has a big role to play here. For example, the days are a lot shorter during winter which means your solar panels aren’t going to get enough sun exposure to produce power. Whereas summer has longer days and solar panels get more exposure.

Another factor is the way your house is positioned. If there’s a lot of shade on and around your property then the solar panels aren’t going to produce as much energy compared to being in a big open field with no trees or shade. 

The trick is to figure out the best position for your solar panels considering your environment, the slope of your roof, and how your house is positioned. 

Energy Output

The area, weather, size of your roof, and the number of solar panels you can install will determine the amount of power you can produce through solar.

What you need to do is figure out how much energy your home needs on a daily basis and then determine how many solar panels you want to install.

Let’s say you want an annual average of around 3,000 kWh, which means you’ll need 6 or 7 solar panels. A more energy-heavy house consuming around  7,050 kWh needs 14 or so solar panels. 


You can calculate how many solar panels you need to power your home or business all year long.

First off, figure out what your hourly energy usage is. Multiply that answer by the amount of peak sunlight hours in your area, and then divide that by the number of watts the solar panel you choose can produce.

how many solar panels will fit on roof

Once you’ve got that down, you can do other calculations to determine the most suitable product for your home. 


When it comes down to deciding how many solar panels can fit on your roof, it really boils down to how much your roof can take. Yes, there are other factors that you should consider but they come second on the list.

If you’re set on getting a few solar panels then, by all means, go ahead and do it. Going solar is the most energy-efficient thing you can do, plus it’s a good way of cutting down on the utility bill. 

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Article by

Alex S

Alex is a co-founder of Shop Solar, a company that he established in 2018 to revolutionize the solar industry by simplifying the process and making it more simple and cost-effective. Under his strategic leadership, Shop Solar has grown into a comprehensive one-stop-shop, empowering over 40,000+ customers to access top-quality solar and storage solutions, comprehensive information, intuitive tools, and professional installation services.

With a passion for innovation and sustainable energy, Alex has successfully expanded the business's reach and impact, serving as a driving force in the company's growth and development. You can browse best seller's here.

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