Powering a home using solar energy requires more than one solar panel. Most families need to combine multiple panels to create a highly efficient solar power system that will serve all their energy needs.

Installers typically place solar panels on roofs, but it can be difficult for people to know the required number of panels they can fit there. If you are among this group of people, you have found the right place to get information about your home’s solar panel roof requirements.

To answer the question of, how many solar panels can I fit on my roof, this article will show you how you can calculate the approximate size of the solar panel system your home needs. But first, let’s review the factors that affect the number of solar panels needed per house.

Factors that Affect the Number of Solar Panels Needed Per House

House with solar panels on roof

Solar panel requirements vary for every home because each home has unique energy needs. To answer your question about how many solar panels can I fit on my roof, let’s take a deeper look at the following factors:

1. Energy Consumption

The total number of rooftop solar panels required for your home depends on the amount of energy your household needs to generate. So in order to determine the number of solar panels that’ll serve your household effectively, you need to know your energy needs. You can do this by checking previous electric bills provided by your utility company.

Add the total energy usage (in kilowatt-hours) and divide it by 12. The result derived for energy consumption for the last 12 months is the information required to determine the solar power supply your home needs and the units of panels that can provide it.

2. Peak Sunlight Hours

Solar panels rely on direct sunlight to perform efficiently. Therefore, the amount of sunlight you get in your residential area is another crucial factor that affects the number of solar panels you’ll need. How? If you live in an area that receives less sunlight, you’ll need more solar panels, and vice versa, concerning the total amount of your household energy consumption.

Efficiency panels in areas with less sunlight mean more solar cells are exposed to sunlight, thereby increasing efficiency and run time. While areas with peak sunlight hours only need the exact number of panels to supply their energy needs – not more, not less.

3. Solar Goals

People have different reasons for switching to solar energy. While some people may want to save money on energy bills, attain energy independence, or reduce their carbon footprint, others may simply want to have an additional power supply. That’s why your solar goal is another factor that affects the number of solar panels you need for your home.

To achieve independent energy usage, you’ll typically need a larger solar energy system than someone who merely wants to reduce electricity bills by supplementing with solar power. So it’s important to determine your solar goals when figuring out how many solar panels you need on your roof.

As you’re now aware, several factors determine the number of solar panels you need for your home, and how many panels you can install on your roof.

How Many Solar Panels Can I Fit On My Roof?

In addition to the factors mentioned above, you can determine the number of panels you can fit on your roof by dividing your roof space by the square feet of the number of panels your house needs. For instance, if the available space on your roof is 1,000 square feet, you can fit around 57 photovoltaic panels.

Considering the fact that the average solar module for residential buildings is 3×5 feet, each of the panels will take 15 square feet. Bearing this in mind, with a 5kW solar power system that many homes require, you’ll need about 20 panels of 250 W on your roof. The fact that this is an estimate means you can always add more or fewer panels depending on your energy needs and the size of your roof.

Generally speaking, the number of solar panels you can fit on your roof depends on how the above factors pertain to your household. While doing the calculations yourself may be a challenge, you can always use the services of a professional solar installer or solar panel installation company. 

We recommend that you can ask them the following questions:

How Do I Know the Number of Solar Panels That Can Power All My Home Appliances

Modern house with solar panels on the roof

Your home appliances take most of your energy consumption. Appliances like dehumidifiers, dishwashers, heaters, refrigerators, clothes dryers, etc., consume more electricity. So to estimate your home appliance energy use, you can ask a professional solar panel installer.

Do I Need To Replace My Roof to Install Solar Panels?

If you are installing many solar panels, you first need to determine whether or not your roof can support them – and if not, you may need to replace the roof. In most cases, you don’t have to, provided your roof is not too old. 

It’s also essential to align the strength of your roof with your solar plans. The professional you’re consulting with can evaluate your roof to answer this question.

What Type of Roofs Accept Solar Panel Installation?

While the solar panel installation processes and required equipment varies for each roof type, you can install solar panels on virtually all roofs. It’s important to involve a professional in this situation to determine the mounting equipment required for your roof, whether asphalt shingle, concrete, rubber, or metal.

How Much Energy Do Rooftop Solar Panels Generate?

Knowing how much solar power your roof can generate is another essential thing to determine before installing solar panels. In most cases, energy production depends on the time of the year and your location. If you’re living in a place like Florida or Arizona where it’s sunny nearly year-round, the solar panels on your roof can produce more solar energy than in places like Seattle.

The time of the year also factors in significantly. For instance, during winter, when the days are much shorter, solar panels on your roof will generate less solar power. Solar panels get more sunlight exposure during summer months, producing more power output.

The positioning of your house also factors in the amount of solar power the roof can generate. This is where the professional comes in. Irrespective of your house position or whether you have a slant or flat roof, a professional solar engineer will establish the best orientation and angle for your solar panels to generate the most energy from the sun.

Roof Size and Total KWH Produced Yearly

Assuming each solar panel is approximately 17.5 square feet with 320-watt capacity using 5 hours of sun every day, the following are roof sizes, the total number of panels, and the total amount of energy they can produce yearly: 

Roof size/Square feet

Total Number of Solar Panels

Total KWH Produced Yearly
















Key Takeaway

Several factors influence the number of solar panels you can fit on your roof. Considering each factor will help you to determine the correct number of solar panels that can serve your energy needs and the budget to get the solar panels. 

Whatever you decide, ensure you consider using a professional solar engineer to give you an expert opinion on creating an efficient solar power system for your home.