Understanding Solar Panel Sizes & Dimensions

Overview: Solar Panel Sizes & Dimensions

The average solar panel size is 1m x 2m. Systems will vary in total size depending on how many panels you install. For instance, a 10-panel system is going to cover an area of 10m x 20m. 

However, you’ll actually need more roof space than this, as solar panels need to be spaced so they don’t shade each other as this would reduce overall system efficiency. A solar panel system size of 5kW is likely to need 25-35m2 in roof space.

This system is likely to weigh over 300 kg including mounts. So, you’ll need a roof that has reasonable structural integrity. And, you’ll want to check installing solar panels of this size won’t affect your homeowner’s warranty. 

Although most websites suggest a 3-3.5kW system is the most common solar panel size, our most popular setup is 5.16kW. This offers the best balance of cost and savings. 

Use our clickable tool here (which includes a free online roof scan), and get the most suitably sized solar panel system on-screen, inclusive of a fixed price.

Our Guide To Solar Panel Sizes & Dimensions

Solar Panel Dimensions

Before purchasing solar panels, you’re going to need to make sure you’ve got enough space to fit them on your roof. 

The average dimensions for a solar panel in the UK are 1m x 2m, with a depth of 30-50mm. 

Using a real world example, we have the LONGi Hi-MO 6, the dimensions for this panel are: 

LONGi is a leading brand in the solar PV panel industry, with other leading brands offering panels that are similar dimensions.

Remember, you’ll need more than one panel. For instance, one of the most popular solar panel systems we install is a 5.16kW (available with or without a storage battery). This setup uses 12 panels in total. 

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This is going to require a reasonable amount of roof space, given the total size of this system would be 27.3m x 13.2m.

We’ve written a detailed LONGi solar panel review here, which are the panels used in the above example. 

You can also go ahead and get a free online roof scan to determine the most suitably sized solar panel setup for your property, using our clickable tool here. 

How Much Roof Space Do You Need For Solar Panels?

As you can see above, the 12-panel setup covers a total area of 27.3m x 13.2m. However, this isn’t the exact amount of roof space you’ll need.

Your installer will need to space each panel, ensuring that one panel doesn’t shade the next. If it does, your solar panel system is going to be working a lot less efficiently than it could be. 

In the case of the 5.16kW system mentioned above, you’d likely need somewhere in the region of 35m2 of roof space. 

Roof space that’s needed obviously depends on individual panel dimensions. The bigger the system, the bigger the panel (or, you’ll need more smaller panels). 

Below are some estimated dimensions for the roof space required based on property size and system size: 

We’ve got a clickable tool that determines exactly what size solar panel system you need based on: 

• Electricity consumption per annum
• Roof space available
• The tilt angle and orientation of your roof (this determines how efficient your system is)

Use our free online tool here, which includes this roof scan. 

Solar Panel Sizes (Power Output)

Solar panel sizes vary a great deal. You’ll be able to find small 50w panels, mainly used for small off-grid setups (motorhomes, workshops etc) all the way through to large panels such as the 590w LONGi Hi-MO 6. 

However, the average solar panel size in the UK in terms of power output, tends to be just over 400w. 

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The setup you see above is one of the most popular solar panel system sizes we install. It’s a 5.16kW (total output) system made up from 12 panels; an average of just 400w per panel. 

It’s easy to bolt-on or remove panels to make a larger / smaller system. As an example, if your property only required a 3.4kW system, you’d simply use 8 panels (still 400w) rather than 12. 

Our clickable tool here works out the best solar panel sizes on your behalf. 

We’ll take into account roof space available, tilt angle and the direction it faces by taking an online roof scan. Accounting for your annual electricity consumption our tool will determine the exact size solar panel system that you need. 

Average Weight of Solar Panels

Jumping back over to the specs of the LONGi Hi-MO 6, the weight of each panel is 27.5kg, assuming you’re going for the large 590w unit. 

If you were to use a 10-panel setup (so 5.9kW system output), you’d be looking at a total weight of 275kg. 

Of course, that doesn’t take into account mounting rails, hooks and clamps. The total weight of everything in the setup that needs to be installed on your roof is going to be in the region of 300kg.

With a weight of 300kg, you'll need to ensure your roof has reasonable structural integrity. 

If your home is relatively new, you'll also want to check that installing solar panels doesn't void the homebuilders warranty for your property.

There’s a more detailed guide to roof suitability for solar panels here. Or, speak to one of our solar PV experts here and they’ll determine if your roof is suitable for an installation. 

What Size Solar PV Panel System Do You Need?

Now we know what to expect in terms of dimensions, weight and solar panel sizes in terms of output, the next step is to determine exactly what size solar panel system you need. 

According to the Energy Saving Trust, a typical solar panel system is around 3.5kW. 

However, for non-optimal roof tilt angle/orientation, this is most likely only suited to a 1-2 bedroomed property. Most properties will need a larger system to make up the deficit thanks to their roof angle and direction being sub-optimal.

This table shows how the tilt angle of your roof as well as the direction it faces affects ideal annual output for your solar panel system: 

As you can see, a roof facing due south and at an angle of 30° is the best. There are plenty of roofs that see potential annual outputs of 30% or lower.

If your roof tilt angle and direction isn’t optimal, you’ll simply need more panels. 

That’s why our most popular system currently is 5.16kW, using 12 panels: 

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There are dozens of factors that affect how much electricity a solar panel system could produce and therefore the perfect solar panel system size for your property including:

• Roof tilt angle and direction
• Shading from trees, neighbouring buildings and chimneys
• Hours of sunlight per day (this varies, with the south getting a lot more)
• The efficiency of your individual panels (top brands such as LONGi work at around 23% efficiency, where as low quality brands work at less than 20%)
• The list goes on!

Use our clickable solar panel sizing tool here. Our tool: 

And for further reading, we’ve got a detailed guide to how many solar panels you need here.

FAQ

What are the standard solar panel sizes in the UK?

The majority of residential solar panel systems use panels that are 400w in size. So, a system using 10 panels would create a 4kW system, suitable for a property such as a 2-bedroom semi-detached house.

‍What are typical dimensions for solar panels?

Most leading manufacturers produce solar panels in a standard size of approximately 2x x 1m, with a depth of 3-5 cm. 

‍Can a solar panel be too big?

Most solar panel system's sizing is over spec'd. That's to allow for any periods of low daily sunlight hours or shading. 

‍What will a 200w solar panel power?

If working at full capacity a 200w solar panel would power a couple of lights, or charge a few small electronics (laptops, phones etc) at the same time.

If you check the back of any plug, you'll see plug rating in watts. So if your laptop uses a plug rated to 100w, you'd be able to charge two laptops at the same time!

‍Do larger panels generate more electricity?

The bigger the output (in watts), the more potential electricity a solar panel can generate; a 250w panel would produce 50% less than a 500w. 

In terms of dimensions, the exact electricity produced by your solar panels is based on its size in watts and efficiency, not its physical size.

Still confused about solar panel sizes?

Ask any questions you might have here. 

Or, use our clickable solar panel tool, which will determine the perfect system size for your property. 

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