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How to Work Out How Many Solar Panels You Need

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Solar panels can save you money, reduce your carbon footprint and protect the environment. If you want to work out the number of panels needed, you can get some useful information from this article.

Types of solar panels

The choice of solar panel type can be based on efficiency, cost and available space. Certain types of solar panels are more efficient than others, which affects the number of panels you need to install.Different types of solar panels can be installed on the roof, but the most commonly installed solar panels are monocrystalline or polycrystalline solar panels.

Monocrystalline Solar Panels 

Monocrystalline solar panels have the highest efficiency at 15 – 20%. This means they can convert 15 to 20 percent of solar energy into usable energy.

This type of solar panel is also space efficient because they generate more energy per area than other types. One square meter of monocrystalline panels will generate 10W more than polycrystalline solar panels of the same size.

On the other hand, monocrystalline panels are the most expensive type of solar panel because of their high efficiency and the quality of the silicon used.

Polycrystalline Solar Panels 

Due to their high temperature resistance, polycrystalline solar panels generate more electricity throughout the year than monocrystalline panels.

Polycrystalline panels are cheaper alternatives to their monocrystalline variants. Although both types are made of silicon, in polycrystalline silicon many pieces of silicon are melted to form wafers for panels, while in monocrystalline silicon they are formed into rods and cut into wafers.

One disadvantage of polycrystalline panels is that they are less efficient because their silicon material is less pure. You can expect an average efficiency between 13-17%.

Work Out How Many Solar Panels You Need

What are solar panels used for ?

Solar panels can power homes, factories, etc., as well as outdoor activities such as RVs, yachts, camping, and more. According to the energy requirements of electrical equipment, solar panels of different powers can be selected.

How to Work Out How Many Solar Panels You Needed

Here are a few things you should know before calculating the number of solar panels you need. If you figure these out, it’s easy to figure out how many you need.

  1. Determine your energy usage

The first step is to see how much electricity you use each year so you can get enough solar panels to generate that much power. Check your most recent electricity bill to see your monthly electricity usage. In most cases, total electricity usage will be shown at the bottom of your bill in kilowatt-hours.

Your annual energy usage will give you the best estimate of how many solar panels you need, as energy usage fluctuates from season to season.

Since energy usage varies widely from month to month, it may be helpful to dig into your monthly electricity bills for the past year, add up your electricity usage, and divide by 12.

However, using just one utility bill to calculate your energy consumption is still good enough for a rough estimate.

  1. The amount of sunlightin the area

Now that you know how much electricity your home uses in a month, you need to find out how much sunlight your area receives. This is usually measured in so-called “peak sunshine hours,” which are essentially the intensity of sunlight in your area.

The monthly peak sunshine hours you get tell you how many kilowatt-hours of electricity a 1kW solar panel will generate in your area in a day. So if your state receives 150 peak hours of sunshine per month, 1 kilowatt of solar energy will produce 150 kilowatt hours of electricity per month.

  1. Know the size of the roof

The size of your roof is a key factor as it determines the number of panels that can be installed on the roof, how much energy it will generate, and how much it will cost. It is also important to consider the suitability of your roof: whether it can support the weight of the solar panel and the angle of the solar panel.

How to Work Out How Many Solar Panels

  1. Dimensions of solar panels

If your roof is small or unusually shaped, the size and number of solar panels are important considerations. With a larger usable roof area, maybe you can sacrifice some efficiency and buy more larger panels to reach your target energy output. However, if you have limited available roof area, or if it’s partially shaded, being able to use fewer small, high-efficiency panels may be the best way to get maximum power in the long run, ultimately saving you more money.

  1. Efficiency of solar panels

Different solar panels produce different power. So the question of how many solar panels you need for a particular house, business or farm can’t be answered all at once for everyone.

The efficiency of solar panels can vary from 150 watts to 370 watts. This number is the amount of electricity produced by a particular panel. If you want to power the same 6 kW system, you’ll need a lot more 150W solar panels than 370W solar panels.


As solar power becomes more and more popular, the demand for solar panels increases. These things should be known before knowing how many solar panels are needed. After understanding, it will immediately calculate the solar panels you need.


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