What Size Solar Panel Do I Need for My Home?

Most UK homeowners install a 1kW to 4kW solar panel system on their roof, which’ll generate between 850 kWh and 3,400 kWh of electricity per year.

The size of your solar panel system will depend on 3 factors: your household’s electricity usage, how big your roof is and your budget.

You can get a bespoke solar panel quote for your property - which also gives you an estimate of the solar panel system size you’ll need - by filling in the short form above.



Solar Panel Size

The average solar panel dimensions are around 165cm (height) x 100cm (width) x 4cm (depth) for residential installations, although sizes do vary slightly between solar panel manufacturers.

The table below shows you the average solar panel size made by the best solar panel brands, based on an independent review we carried out:

Solar Panel Brand
Average Solar Panel Dimensions
Canadian Solar
195cm x 90cm x 3cm
LG
170cm x 100cm x 4cm
Panasonic
160cm x 105cm x 4cm
Sharp
160cm x 100cm x 4cm
SolarWorld
200cm x 100cm x 3cm
Yingli Solar
165cm x 100cm x 4cm


Solar Cell Size

A solar cell - also known as a photovoltaic (PV) cell - generates electricity when it’s exposed to light. Individual solar cells are small and powerless on their own, which is why a large number of them are needed in each solar panel to generate enough electricity for your home.

A solar cell is usually about 15cm (height) x 15cm (width). A residential solar panel is typically made up of 60 solar cells; although, again, this does vary between solar panel manufacturers.

The table below shows you how many solar cells are contained within the solar panels made by the best solar panel brands:

Solar Panel Brand
Number of Solar Cells in Solar Panel
Canadian Solar
60 to 144
LG
60 to 72
Panasonic
72 to 96
Sharp
48 to 72
SolarWorld
60 to 72
Yingli Solar
60


Back to top



Solar Panel System Size

A solar panel system simply refers to how many solar panels you have installed on your roof. A single solar panel typically has a power output of between 250 watts and 350 watts. However, most of your home’s appliances will need kilowatts (kW) of power to work and you’ll therefore need several solar panels to meet your home’s energy needs.

Solar panel systems sizes are measured in kW. Residential solar panel systems typically range in size from 1kW up to 4kW. A solar panel system bigger than this will probably be too large (and heavy) for your roof, and generate far too much electricity than is needed.

The table below gives you a quick overview of the most common solar system sizes for properties in the UK, including how many solar panels they’re made up of and how much roof space they need in order to be installed.


What Size Solar Panel Do I Need? Solar Panel System Size Comparison

Solar Panel System Size
Number of Solar Panels
Roof Space Required
1kW
4
8 sq. metres
2kW
8
14 sq. metres
3kW
12
21 sq. metres
2kW
16
28 sq. metres

How much could you save with Solar Panels? What's your average monthly electricity bill?


Back to top



How to Size a Solar Panel System for Your Home

1. Calculate How Much Electricity You Use

The more electricity you use, the bigger the solar panel system you’ll need to cover most (or all) of your energy usage. How much electricity your home uses is measured in kilowatt hours (kWh) and this information can be found on your latest energy bill.

The table below gives you an idea of what size solar panel system you’ll need, based on how many kWh of electricity it produces per year and the size of your household.

Solar Panel System Size
Annual Electricity Output
Suitable For
1kW
850 kWh
1 adult
2kW
1,700 kWh
2 adults
3kW
2,550 kWh
Family of 3
4kW
3,400 kWh
Family of 4+


Obviously, if you only want your solar panels to supplement a small amount of your home’s electricity usage, you only need to get a small solar panel system.


2. Work Out How Big Your Roof Is

The size of your roof will directly affect the size of the solar panel system you can install. For most homes, roof size shouldn’t be an issue unless you live in a flat, for instance.

If your property does have a small amount of available roof space, it’s wise to install solar panels with a high efficiency rating of at least 19%. A small solar panel system with high efficiency should produce a similar amount of electricity to a large solar panel system with a lower efficiency.

As a rough guide, you’ll need about 7 square metres of roof space for every kW of power solar panels generate

Ideally, solar panels should be installed on a south, west or east-facing roof that’s out of shade. It’s not cost-effective to install solar panels on a north-facing roof or one that is partially (or completely) in the shade, since your solar panels won’t receive enough light to generate an adequate amount of electricity.

Only include suitable areas of your roof when you’re calculating how big it is. For example, if the rear of your home’s roof is south-facing and has an area of 5 metres x 3 metres out of shade, you’ll have 15 square metres of available roof space on which to install solar panels (enough for a 2kW solar panel system).


3. Know Your Budget

The bigger the solar panel system you install, the more it’ll cost. If cost isn’t a problem for you, then we’d recommend installing the biggest solar panel system as possible. This will maximise your Return on Investment (ROI) since you’ll earn more from the Feed-in Tariff (a Government-funded scheme that rewards homeowners for generating renewable electricity).

If you’re limited by how much you can spend, many companies offer you the option of buying your solar panels on finance. This can make them more affordable initially by spreading the cost over several months, but be mindful that you could end up spending hundreds (or even thousands) more than your solar panels are actually worth as you’ll often be charged interest. We’d recommend paying for your solar panels upfront, therefore, if you can.

The table below provides you with the estimated costs of the different sized solar panel systems:

Solar Panel System Size
Estimated Price
1kW
£1,500 to £3,000
2kW
£3,000 to £5,000
3kW
£5,000 to £6,000
4kW
£6,000 to £8,000


Get a Bespoke Solar Panel Quote for Your Home


Back to top


Spread the Word!