How Many Solar Panels Should I Buy? Solar Energy 101

How Many Solar Panels Should I Buy? Solar Energy 101


Nowadays, solar energy is becoming more popular because it’s kinder to the environment and, over time, can be more affordable. However, when installing a solar energy system, it’s vital that you get it right and install a system that can effectively meet your needs. But how do you calculate the size of your system and the number of panels you need?

In this post, we’ll look at this question in more detail.

Understanding Your Power Usage

The first step in figuring out how many solar panels you should buy is understanding how much electricity you use. When you do, you’ll have the figure that forms the basis for calculating the size of your solar energy system. To calculate this figure, you’ll need to look at your electricity bill or smart metre reading for the past 6 months or so and calculate an average from that. You can also make adjustments if you anticipate that your usage will increase or decrease.

Solar Panel Output Options

Next, you’ll need to know the output of the solar panels you plan on using. You’ll typically use panels with outputs of between 300 and 400w, as these are becoming increasingly popular. Keep in mind, however, that you might get by with lower outputs or need higher outputs based on your needs and requirements.

Installation Considerations

Before installing your system, there are also some other important considerations you should take into account. For one, you’ll need to ensure that you have enough space available for a system that meets your needs. Generally, a 5kW solar energy system takes up about 25m² of roof space with higher capacity systems needing more of your roof area.

Orientation also plays an important role. Generally, you want your solar panels to face north. This allows them to get maximum exposure from the sun. However, if this is not possible, you can also install them to face east, west, or south. If this is the case, you should be aware that they might be less efficient.

Calculating the Size of Your Solar Energy System

Let’s look at how you will calculate the size of your solar energy system. Here, you’ll need to follow these steps:
  • Calculate your electricity usage. We’ve already shown you how to calculate your average electricity usage. You’ll use this figure in the other steps dealt with below.
  • Look at your sunshine hours. Next, you’ll need to look at how much sun you can expect in your area, which is measured as peak sun hours. This shows you how much electricity a 1kW solar system will generate. For example, if your peak sun hours are 150 per month, a 1kW solar system will generate 150kWh of electricity.
  • Calculate the size of the system. Now you can calculate the size of the system. To do this, you’ll divide your electricity usage by the peak sun hours in your area. So, if you use 900kWh per month and your area has 150 peak sun hours per month, you’ll need a 6kW system. From this, you can also calculate how many solar panels you need by converting kilowatts to watts and dividing them by the panels’ output. Using the example above, you’ll need 20 panels if they have outputs of 300w.

There you go, now you can calculate the size of your solar system and the number of panels you need. This will ensure that you install a system capable of meeting your needs. Now, the only thing remaining is to contact an expert in solar panel installations to get started.