Solar panels have skyrocketed in popularity because they’re an eco-friendly way to power your home. Not to mention the cost savings on your energy bills which many UK homeowners are taking advantage of.
But the initial investment of solar panels can rack up quite a hefty bill. As a result of this, I’ve heard people talking about installing as few solar panels as possible.
Let me tell you that’s not a wise idea. It’s so important to view solar panels as an often lifetime investment (good quality panels can last up to 30 years) and, as such, getting the correct number of panels is a must. It’s also worth keeping in mind that the cost of individual panels has decreased significantly in recent years, making solar energy more accessible to everyone.
Not having enough panels means that your solar system won’t generate enough energy to power your home. If you’re looking to reduce, or even completely cut out your electricity bill, this is something that’s well worth considering.
With that in mind, a lot of people have been asking how many solar panels you need to power a house. So, let’s answer this question and help you make the most informed and effective decision.
Average Number Of Solar Panels Required For Houses In The UK
There are certain factors that will determine the correct number of solar panels your home needs. I’ll talk more about these later in this post but for now, here’s a quick guide on the average number of solar panels recommended by experts based on the size of a property.
- The average one-bedroom house will need six solar panels for maximum efficiency.
- The average three-bedroom house will need ten solar panels for maximum efficiency.
- The average five-bedroom house will need fourteen solar panels for maximum efficiency.
I would also recommend considering the size of the solar panels in accordance with the size of the property.
For example, smaller homes with just one bedroom may be able to use 2.1kW solar panels while a three-bedroom property would typically require 3.5kW. At the other end of the scale, five bedroom homes would require fourteen 4.9kW solar panels.
It’s important to speak with your installer who will be able to provide you with individual information relating to your property and its needs.
What Factors Affect The Required Number Of Solar Panels?
As I have discussed, there are various things that will affect how many solar panels you need. While the above guide is accurate, you may find that you need slightly fewer or more solar panels depending on the following things.
Type Of Solar Panels
There are several different types of solar panels which include monocrystalline, polycrystalline and amorphous. In the UK, most installers use monocrystalline solar panels as these tend to be the most efficient and generate the most energy. What’s more, they generally have greater longevity than other types of panels.
Monocrystalline panels offer up to 24% efficiency while polycrystalline may only be up to 16% efficient. For this reason, homeowners choosing to install polycrystalline panels will typically need more if they want to achieve the same efficiency.
Number Of People In Your Home And Energy Consumption
Naturally, the more people that live in a property, the more energy will be consumed. This is perhaps one of the most important considerations when installing solar panels as the last thing you want is for your new system to be unable to generate enough power.
Before you even start thinking about having solar panels installed, it’s really important to check your annual energy usage. You can do this simply by taking a look at your electricity bill or, if you cannot find this information, you can contact your supplier and they’ll be able to help you.
Once you have this figure, you can divide it by 265 (the average amount of energy in kW that a standard-sized solar panel produces) and this will tell you how many panels you’ll need.
Location And Orientation
It goes without saying that solar panels require light from the sun in order to generate power. Now, a common misconception is that the panels need to be in direct sunlight in order for them to work.
This isn’t strictly true since your solar panels will still work on overcast days or if they aren’t in direct sunlight for the whole day. Of course, the more direct sunlight they receive, the more energy they will produce.
For this reason, the number of required panels is affected by your property’s location. In the UK, we don’t get as many hours of sunlight as some of our European neighbours so there may be a need for more panels.
Furthermore, if your home is set in a location where there’s a lot of shade or where sunlight is obstructed, this will also have an impact.
The orientation of your roof is something else to consider. Generally speaking, it is recommended that solar panels be placed on a south-facing roof although east or west-facing are also acceptable. While solar panels can, in theory, be placed on a north-facing roof, this is generally discouraged as the amount of sunlight they will receive won’t be sufficient to power your home efficiently.
For east or west-facing roofs, it may be necessary to install a greater number of solar panels in order to achieve the same efficiency as panels placed on a south-facing roof. Again, these are decisions that your installer will be able to help you make.
Do You Have Enough Roof Space For Solar Panels?
Once you have worked out how many solar panels you need to power your house, you then need to ensure that you have enough space to place them.
Most solar panels measure around 1.6m² so you’ll need to multiply this by the number of panels and then measure your roof to make sure that there’s enough space to install them.
However, even in situations where space is limited, that doesn’t mean that you have to forget about the idea of going green. It is possible to purchase more powerful solar panels and therefore reduce the need to install as many.
Space isn’t the only thing to think about when assessing your roof for solar panel suitability. Even if there is enough space to go ahead with the installation, you’ll also need to consider the state and quality of the roof.
Your roof should be stable enough to hold the weight of the solar panels. If there are structural problems, it’s a good idea to address these before continuing with the installation.
