If you’re thinking of adding more solar panels to your solar system or setting up an entirely new setup, knowing the panel’s size is a must. Understanding the size of solar panels that you need will let you utilise solar energy effectively.

There are a lot of factors associated with selecting the correct panel size. You have to check your electricity consumption, the number of appliances you’ll power, and the panel’s efficiency. The associated budget and roof space are also important factors to consider.

Whether you’re confused or need more help figuring out the right solar panel size for your system, you’ve landed at the right place. This post covers everything you need to know about solar panel sizing and help you choose the right one for you. So, let’s jump right in!

Why is Solar Panel Size Important?

Determining the size of solar panels is essential for maximum utilisation of solar energy. It becomes an even more crucial factor for those living in areas with uneven sunlight or adverse climatic conditions. With the right sized panels, you’ll be able to get the most out of your PV system.

Knowing the right size also lets you make use of your roof space properly. So, no more cramming multiple panels together. You can have a clean solar PV setup offering cleaner energy!

In general, solar panels that are generally used for homes are about 65×39 inches in dimension. Some solar manufacturers make 61.3×41.2 inches panels also. You can also talk to some solar panels users to know about their panel’s sizes.

And how can you forget the money you save while figuring out all this? The right sized solar panel will not only be more efficient, but it will be easier on your wallet too.

Factors to Consider While Determining the Solar Panel Size

Want to reduce your carbon footprint and make the best of what Mother Nature has to offer? Then going solar is the way to go. For those struggling with panel sizing issues, continue reading this section to get the required know-how.

Energy requirements

Roof Solar PanelsThe most crucial factor while determining panel size is the amount of energy you need to produce. You must pick a panel as per the energy consumption of your residence.

For this, have a look at your electricity bill. Even if the document seems boring, look for your monthly consumption. Some electric bills will include the monthly value. If it isn’t there, just divide the average value by 30 to get it. Similarly, for finding the yearly consumption, divide the average daily consumption by 365.

Other tips to figuring out your monthly consumption –

  • You can check out online electricity consumption calculators to find out your average and monthly usage.
  • You can ask your electricity provider to check the meter readings and give you the exact value.

Climatic conditions

Before purchasing a solar panel or setting up a solar system, take some time out and think about your weather conditions. While some areas bask in the sun throughout the year, some regions are not so bright.

So, the same solar panel installed in both regions will have different outputs.

Does this mean you need larger and more panels if you live in a gloomy area? Not necessarily. You need to select the optimally sized solar panel according to the amount of sunlight you receive.

Follow these steps to figure it all out –

  • You first need to figure out the peak sunlight hours in your area. Usually, it is between 9 to 3 PM every day.
  • Then divide your daily consumption in kWh by the peak hours. You will then get the energy your panel needs to produce to meet your daily consumption.
  • Multiplying this value by 1000 will give you the watt usage. You can use the value while buying the appropriately sized panel.

This vital piece of information will also help you save time and money while looking for the perfect panel size.

Peak sun hours

Peak sun hours are the daily hours where the intensity of the sun is highest. This intensity has to be 1000 watts per square meter or more in a peak hour. So, as the day reaches noon, the intensity increases, and so does your panel’s absorption.

The intensity will decrease by dusk, so getting your batteries and the solar system charged earlier is better. Thus, to make things simpler while understanding a solar panel’s size, getting a better idea about the peak solar hours in your area is paramount.


When it comes to selecting a panel’s size, making a note of the amount of space you have is extremely important. The area per square foot, orientation, and tilt of your roof/lawn will tell you the panel size it can handle.

Most users prefer to install four panels on the roof. So, if the average panel size is 1.6 square meters, you’ll require 6.4 square meters of roof space. Check out the following specifications –

  • A 2 kW solar system might require 150 square feet of space approximately.
  • A 3 kW solar system may need an estimated area of 220 to 225 square feet.
  • For a 4 kW system, you might need a lot of space, about 301 square feet.

The expenses will vary for all these options, so you must carefully measure the area before selecting the panel. Consumers having ample roof space can install up to 12 panels for maximum efficiency.

Note: You also have to consider the direction of your solar array to get the most out of it. For instance, an East or west-faced solar PV array produces less output than a south-facing array.

So, if your roof is East or West faced, you might need a larger solar panel size for better efficiency and output.

Try to keep away obstacles such as skylights, vents, and tree branches, interfering with your setup.

Solar battery size

Every solar panel system needs a powerful battery to store the energy generated during the day to be used at night. So, when you add a battery to your system, you have to factor in its size.

For example, if you need a battery to work as an emergency backup for a few hours, the solar panel’s size won’t matter much. But, to run your home for more than 24 hours, you might want a powerful battery to store enough power. In that case, your solar panel system size will increase to keep the battery fully charged.

Surrounding environment

Solar Panels on RoofAmongst all this technical stuff, you can’t forget your environment. Various obstacles in your environment might hamper your panel output. But why is this related to panel size? Let us understand.

If you live in an area filled with greenery, large trees may tilt on your roof, spreading the branches over your panels. Or, if tall buildings are adjacent to your house, it may hamper the amount of sunlight reaching your solar panels.

Both these factors prevent the solar panels from absorbing sunlight properly. In such cases, you may want to increase the panel size to compensate for energy losses.

Solar power losses

All solar power systems experience power losses. The loss percentage is small but can significantly affect your decision to select the right solar panel size.

Let’s check out the details –

  • When DC electricity is transferred to the solar inverter, there is a system loss of about 2%.
  • In addition to this, when the inverter converts DC electricity to AC, it suffers another power loss of approximately 3%.
  • You receive around 95 or 96% of usable electricity for running appliances and your home at the end of the day.

So, you need to select an appropriately sized panel, which can offer you the necessary power even after system losses.


Even after understanding all the technical nitty-gritty, your panel shopping will depend heavily upon your budget. If you have focused on all the factors discussed until now, you might have a rough estimate of the solar panel size you can afford.

You have to consider other factors too. For instance, if your roof isn’t too spacious, you might have to install more or larger panels. This will enable you to squeeze in more solar power.

On the other hand, you can install multiple panels if you have a higher budget and a spacious rooftop. A powerful battery and an inverter can set you up for good!

Note: Always count in additional expenses such as buying equipment and expert consultation while preparing your budget. If you can survive some power losses while staying within your budget, go for that solar panel!

How to Find Out The Correct Solar Panel Size?

The best way to calculate a solar panel’s size is by contacting a solar installation company. You can check online for size calculation tools offered by many manufacturers. Or, you can directly contact the retailer.

Any reputed solar manufacturer will analyse your energy consumption needs and give you a free quote about the panel size. These calculations will be highly accurate.

In most cases, you’ll be able to adjust the calculations as per your requirements. However, to get the most precise quote from a manufacturer, you have to do some digging. You may have to collect electricity bills for an entire year!

Is there a simpler way?

If you feel that contacting the solar manufacturer is tricky, you can check out Google. There are online solar panel size calculators that might do the trick for you. These portals will require you to enter the following details –

  • Your home’s location
  • Pitch of your roof
  • Roof shade
  • Your electric consumption

These tools will give you an idea of the various solar panel sizes that fit your home. You might also get additional information such as annual savings, related expenses, and consumption with the sizing info.

How Many Solar Panels Will I Need?

While determining the optimum size for your solar panels, you also must check the amount you need. The cumulative solar power capacity in the UK is about 13,563 MW, so you might hear a lot about the number of panels. Let’s deep dive into this.

Solar Panel CalculatorFor homes having five or more residents, a 6 kW solar system will be perfect. A 5 kW solar panel system will suit homes having four people or less. However, the most common solar system size is 4 kW, which can support a home of 3 to 4 people.

Now, we’ll get to the size and the number of panels –

  • For a 3 kW solar system, 12 panels will suffice. Twenty-four panels will be suitable for a 6 kW solar panel system.
  • The solar panel size will also depend upon whether you want to power your entire residence or just a portion of it.
  • So, if you want to go full-solar, the size and the number of panels will increase automatically. On the contrary, a fewer number of panels can handle a percentage of your electricity needs.

So, take a closer look at the number of people at your residence and your electricity needs before narrowing down upon a panel size.

Why Should I Get a Solar Battery?

The whole point of figuring out the correct solar panel size is to enhance your energy savings. As we have already talked about the solar battery size previously, you might think, “Is getting a battery necessary?”

Buying a powerful solar battery will reduce your dependence on the grid. You also won’t have to worry about purchasing multiple panels to increase the system size. A battery will help you stabilise your power consumption.

Other advantages of buying a solar battery include:

  • You can store the unutilised energy without sending it back to the utility grid.
  • Solar batteries are environmentally friendly and don’t cause too much pollution.
  • They can help you reduce your electricity bills significantly.

The money you save by installing solar panels and a battery will depend upon the battery discharge rate and solar panel size. Therefore, your solar panel’s size and the type of battery you choose is interrelated.

Types of Solar Batteries

Proper utilisation of your rooftop space and keeping things under your budget will be possible by choosing the right type of solar panel. The two main types of solar panels you will come across are monocrystalline and polycrystalline.

Monocrystalline Solar Panels

These panels have a high efficiency rate of about 15 to 20% and are the most popular. They don’t take up too much space for installation and generate maximum usable energy. For one square metre, these panels can generate 10W more than other panels.

Due to such unique features, they are a bit expensive.

Polycrystalline Solar Panels

These solar panels have 15 to 17% efficiency and are more temperature tolerant than monocrystalline panels. So, they generate a little more energy throughout the year.

Although they are less expensive, they take up more space than monocrystalline solar panels.

To sum up

By now, you should have understood everything about a solar panel’s size. The right size is essential to generate the maximum energy while keeping your bills in check. It also prevents you from overspending on a panel that might not suit your needs.

Be sure to consult a solar technician or a manufacturer before making the final call. Whenever you get stuck, our handy guide will pull you out!