How many solar panels do I need?
You may have made the decision to invest in solar energy. It’s cleaner, it can help you save money on your energy bills, and it’ll aid the Net Zero goal in 2050. But the tricky question is, how many solar panels do you need in the first place? We've offered our guidance below on panel quantity, as well as what factors to consider to make your decision.
It’s important to note that your solar panel provider will also offer their advice and guidance on how many solar panels you’ll need, but this guide will give you a good idea when working out costs and setting expectations.
What to consider when deciding panel quantity
Working out how many solar panels you need for your home will depend on several factors:
- How big is your house?
- How many people live there?
- How efficient are your chosen solar panels?
- How much electricity do you typically use?
- Do you plan on using more electricity in the future?
- How many daylight hours do you get and how is your roof angled?
Once you’ve answered these questions, take a look at the below table which outlines how many panels the average home with each of these variables may need:
These figures are based on Type 1, 108 Half Cell Monocrystalline panels operating at 3.85 Watts.
While we can’t give you a quick and easy answer to the number of panels you’ll need in this article, we recommend you keep reading to get an estimate, which will help you in the planning and preparation side of things. Then you can contact Wickes Solar’s well-trained team who can give you information on costs, savings, and what will be best for you and your home.
How do I find out how much electricity I use?
The first thing you’ll need to do is work out the average amount of electricity you use every day. If you’ve got a smart meter, this is already worked out for you. If not, just look at your electricity bill and you should find an estimate based on the amount of kWh you’ve used previously.
On average, here’s how much energy is used in UK homes:
It’s also worth considering your future energy use. Anything from the number of people living in your home to the appliances you use, changes the amount of energy you consume every day. Planning for the future can save you from under or overestimating how many panels your home needs.
So, how many solar panels should I buy?
Once you know your energy consumption, you can work out how many panels you’ll need with ease. Monocrystalline photovoltaic panels are most common in the UK as they’re more efficient and don’t need much space.
There are a few sizes and types of monocrystalline panels to choose from:
60 or 72 Cell Monocrystalline Panel
Solar panels are made up of cells, and the number of cells in a panel determines its size and how much energy it generates.
- A 60-cell monocrystalline panel can generate 325W to 335W and measures 1665mm long x 1006mm wide x 35mm high.
- A 72-cell monocrystalline panel can generate 385W to 400W and measures 1986mm long x 1006mm wide x 40mm high.
- A 60-cell panel is great for small spaces, but if you’ve got room for the larger 72-cell panel, this is better value for money on a cost-per-watt basis.
108 Half Cell Monocrystalline Panel
Half-cell panels are innovating the solar industry, and they’ve recently become much more affordable. These panels are made up of 54 full cells cut in half (which is why it’s called ‘108’). This design reduces the resistance for energy to reach the inverter, which makes it more efficient than full cell panels.
- 108 Half Cell monocrystalline panels can generate a maximum of 420W and measure 1722mm long x 1134mm wide x 30mm high.
What factors affect the number of solar panels I need?
When you’re estimating the number of solar panels you need, several factors come into play. These include the position and angle of your roof, available roof space and its strength, the type of roof tiles, and the amount of daylight your house gets.
Why does the position and angle of your roof affect how many you’ll need?
The position of your solar panels determines how much energy they generate. In the UK, south facing roofs are preferable as they get more direct sunlight, but this isn’t essential. Panels on east and west facing roofs see a 15-20% drop in efficiency. It’s generally inadvisable to put panels on north facing roofs.
Most homes in England and Wales have roofs pitched between 40° and 50°, which is great since most solar panels work best at a roof angle between 35° and 40°. Solar panels work at almost any angle and can even be fitted on flat roofs. But you may need some extra panels to make up for the loss in efficiency if your roof is outside the 35° and 40° range.
How many batteries will I need for my solar panel set-up?
How many batteries you’ll need for your set-up is usually between 1 and 3 for the average UK household. To determine the quantity, you’ll need to consider what you’re powering, how much energy you typically use, how large your solar array is, and whether you need longer back-up due to power outages or going completely off grid.
In summary, fewer batteries will mean a lower cost but you’ll be given a shorter backup, whereas more batteries will cost more, but you’ll have longer reliability.
Overall, how many solar panels you’ll need depends on your household’s needs and your home’s structure. As mentioned earlier, our expert team are always on hand to have a no-obligation discussion with you on a potential solar set-up. If you found this article useful, read our guide on solar panel costs.
