What is the main purpose of solar panels? How do they work?

Keep on reading this short guide on solar panel sizing and learn from the valuable insights we’ll be sharing.

If you are looking for a cleaner and more efficient source of energy, solar is the way to go. A lot of people are intimidated by the high initial cost, but such should not be the case. PV solar panels are expensive but consider it as a long-term investment.The longer you use the panels the higher is the return. It is a greatway to save money through the years while saving the environment as well.

Solar panel installation is quite complicated. You need to understand a lot of things, and one of the most important is sizing. Start by assessing your needs, and from here, it is easier to determine how many solar panels are needed. 

The Importance of Considering Solar Panel Size

Solar panel sizing is important because of its cost implications. The larger the panels are, the more expensive they will be. Unfortunately, not all of us have the luxury of financial resources to tap solar energy.

More so, solar panel sizing is also crucial to determine compatibility with your rooftop or home. You are often limited to the size that your roof can accommodate. You cannot go beyond such.

Sizing does not only refer to the dimensions of the solar panel. Instead, it also refers to the power output, especially wattage. A higher wattage would mean a better ability to supply your power needs.

Determining Your Energy Usage

The best way to estimate the size of the solar panels you will need is to estimate your current energy usage. When you are aware of your current electric consumption, it is easier to determine the size of the panels you should install to enjoy significant savings.

An easy way to know your energy usage is to look at your electricity bill. Look for your monthly consumption, which is expressed as kilowatt hours or kWh [.1] – If this value is not stated, then you can simply look at the beginning and ending meter readings. Subtract and the difference will be your electric consumption. From here, you can have an idea about how much electricity should be supplied by the solar panels that you will be installing.

Solar Panels Size Guide

The Dimensions of Solar Panels

When talking about solar panel sizing, one of the most important is to determine the size of the panels. This can be different from one manufacturer to another. The most important is that it fits your home’s roof and must provide your energy needs.

There are two traditional configurations in solar panels – 60 and 72-cell. The cells are the smaller squares that make up each panel. They are the ones responsible for the absorption of energy from the sun, and with the help of other components, such as the solar inverter, such energy is converted into electricity that powers the connected appliances.

In a 60-cell configuration, the width is often 3’3” while the height is 5’6”. Meanwhile, in a 72-cell panel, the width is the same while it is taller at a height of 6’5”. You can find other sizes with bigger configurations, but they are not as common. A good example of this is the Panasonic panel with 96 cells. In these panels, each solar cell will be 5”x5” or 6”x6” depending on the specific brand you will choose.

The Weight of Solar Panels

Now that we talked about the dimensions, let’s quickly touch base on the weight of the panels. When they are too heavy, they can put too much stress on the rack or your roof, resulting in premature wear. Luckily, most manufacturers know this, which is why they are using the ideal size in the solar panels that they are manufacturing.

Solar panels are often heavy because of their premium construction. This makes them more capable of withstanding the harsh environments, including rain, wind, and snow, among others. On average, each panel weighs 40 to 60 pounds. At such weight, you will definitely need a helping hand to safely complete its installation.

Solar Panels Size Guide: How Many Solar Panels Do You Need?

How Many Solar Panels Do You Need?

There is no easy way to answer this question. It depends. The most important factor is your electric consumption. The more electricity you are using, the larger are the solar panels that you will need. It follows that the bigger your home is, the more panels you have to install.

On average, Americans consume 10,400 kWh of electricity in a year. This translates to a monthly consumption of 867 kWh. In a typical home, there is a need for 28 to 34 solar panels to provide 100% energy needs. Take note, however, that this is only applicable to residential users. For commercial applications, larger solar panels are necessary.

Factors Affecting the Right Size of Solar Panels

As mentioned earlier, there is no magic number when it comes to the size of the solar panels suitable for your needs. You have to consider several factors, including those we’ll be briefly talking about below.

  • Energy Demand: This is perhaps the most important factor to consider. By asking how much power you are using, you can determine how large of a solar system set-up is appropriate to meet your demands.
  • Climate: The effectiveness and efficiency of solar panels will depend on the amount of energy it absorbs from the sun. If it is often cloudy or rainy in your area, then the panels may end up inefficient. In colder climates, you might need larger panels to maximize energy absorption.
  • Sunlight Hours: This is one factor that is directly related to climate as earlier mentioned. The shorter sunlight hours you are getting, the larger the solar panels should be.
  • Budget: If you opt to have more and larger solar panels, the higher the cost will be. This is a stumbling block to solar adoption. If you are on a budget, start with small and few solar panels to power basic appliances. As you realize its benefits, it is easier to be convinced that the cost is justifiable.
Solar Panels Size Guide: How Many Solar Panels Do You Need?

Improving the Efficiency of your Solar Panels

While sizing your solar panels is important in improving its efficiency, there are other things that you can do. To maximize their performance, take note of the things briefly mentioned below.

  • Install the panels properly. The most important is toavoid areas with shade as it will inhibit the absorption of the sun’s energy. Avoid places with structural barriers and trees. They can also have falling objects, which can break the solar panels. This will be a costly problem to deal with.
  • Speaking of installation, the orientation of the panels is another crucial consideration. They must be angled in such a way that they will absorb most of the light from the sun. If you are from the United States, then you should be installing the panels facing south.
  • Choose the right solar panel. Brands matter, so pick one made by a reliable company. This way, you can be confident that it can deliver optimal performance even after many years. Consider the warranty as well so that you can rely on the assistance from the maker of the panels in case you experience any problem.
  • Hire a professional installer. While some people will consider it as a DIY task, if you are not confident about your skills, it is best to hire professionals. With their expertise, you can make the most out of the solar panels that will be installed.
  • Keep the solar panels clean. It is crucial to exert time and effort in care and maintenance of the panels to keep them working in perfect condition. Dirt and dust will accumulate on the cells. In turn, they will minimize the efficiency in solar absorption, resulting in poor output. Not to mention, they can also be prone to problems that will be costly to address.


Now that you reached the end of this quick guide, we hope that you learned a thing or two about solar panel sizing. As noted above, the size that you need is dictated by several factors, such as your electric consumption and space availability in your roof. In most cases, you will need 28 to 34 solar panels. This is based on an average annual electric consumption of 10,400 kWh [.1]. The height and the width of the panel, on the other hand, will depend on the number of cells, which can typically range from 60 to 72.

[.1] https://www.mit.edu/course/21/21.guide/use-tab.htm

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