How Many Solar Panels Can I Fit on My Roof?

A common question we receive is how many solar panels can I fit on my roof? It’s an important factor to take into account when considering a solar system for your house.

Luckily for you, that is exactly what this guide covers. 

If you’d prefer not to do the calculation yourself, you can use our solar panel calculator to work this out for you. Simply input your postcode and we’ll help you calculate it.

Not only does this save you from having to read the entire article and crunching the numbers, but you’ll also be given a breakdown of the estimated costs, energy output and savings for your home. 

How to Calculate How Many Solar Panels Will Fit on Your Roof

The easiest way to do this would be by using our solar panel calculator. However, if you fancy crunching the numbers yourself, here is a step-by-step process for working this out. 

1) How Much Roof Space Do You Have Available?  

2) Take into account roof edge clearance 

3) Find out the size of a single solar panel  

4) Calculate how many panels will fit on your roof 

How Much Roof Space Do You Have Available? 

The most obvious factor in determining how many solar panels can fit on your roof will of course be the size of your roof, and whether you are able to utilise all of that space. Chimneys, skylights and roof windows can get in the way, thus decreasing the available space. You will also have to consider any parts of the roof that are constantly shaded.

Calculating this accurately may prove to be tricky but you can start off by working out the total roof area by multiplying your roof length by its slope height and then multiplying this by two. From here, you would have to work out how much space is taken up by chimneys, skylights etc, and deduct that from the total roof area. 

The good news is that you won’t have to worry about having roof space for solar energy batteries and inverters, as these can be installed within the property and will not take up roof space. They’re likely to be installed in a loft, a garage, or an internal storage space.

Note - We consider all of these factors and more when helping you design the most efficient green investment for your property.

How Much Roof Space Is Needed for Solar Panels?

This will depend on the size of the solar system. For a small 3kW solar system, comprising 8 to 10 panels (1722 x 1134 x 30) you would require between 20-25 m2. For a larger 6kW solar system, this would double to between 40-50 m2.

How close can solar panels be to the edge of the roof?

You’ll also need to take into account how close the solar panels can be to the edge of the roof as some clearance is necessary. Panels should never extend beyond the edge of the roof as the wind can be stronger there. To keep your property safe, and to abide by MCS regulations, we try to maintain a margin of 30 cm around the panels.

What is the size of a solar panel?

In recent years solar panels have become smaller but more efficient. Current solar panels used for domestic properties are about 1722 mm by 1134 inches, with some variation among manufacturers.

What size solar panel do I need?

The size of PV solar panels you need depends on several factors. This can make the calculation quite difficult so we’d recommend using our free solar panel tool to do the leg work for you.

However, if you insist on working this out yourself, you can use the following figure for a typical solar panel that we’d fit on our customer’s roofs - 1722 x 1134 x 30 (a single panel would take up 1.95 m2 of roof space).

Calculate the Number of Panels That Will fit on Your Roof 

Once you have worked out how much roof space you have available and know how large a single solar panel would take up, it’s a case of simply dividing the first figure by the latter to work out how many solar panels would fit on your roof. 

What is the maximum number of solar panels allowed in the UK?

There is no limit to the number of solar panels you can have but there is a limit on how many solar panels can fit on your roof. When calculating this, it’s always important to ensure that there is enough space for them and that the structure of your roof can support the weight of the solar panels.

Can you have too many solar panels?

Yes, as it does not always make sense economically to install as many solar panels as your roof can possibly fit. This could be because you don’t need as many solar panels to generate the electricity your household uses, for example. 

Final Thoughts

We hope this article provided the answers you were looking for. If you need more information about solar panels – we’ve got you covered! Head over to our Green Guides section or check out our Gurus FAQs about everything solar equipment, solar installations, and taking care of your panels!