How Many Solar Panels Do I Need?

Most residential solar panel systems are made up of between 8 to 18 solar panels.

The number of panels you will require depends on the size of the system and its efficiency.

Enter your postcode in the form above to compare the prices of solar panel installers in your area.

How many solar panels do I need?

The amount of solar panels you will need to fit on your roof will depend on what size solar panel system you require to meet your needs. Solar panel systems are sized in kW (kilowatts). Domestic systems typically range from 1kW to 5kW.

The Energy Savings Trust estimates that an average 3 bedroom house in the UK uses around 3,000 kWh of electricity per year. An average 3kW system should produce around 2,550 kWh of electricity per year and a 4kW system should produce around 3,400 kWh annually, at optimal output.

This is why it is suggested that the average family home should look at installing a 3-4kW solar panel system. If you live in a smaller house, with only one or two people, a slightly smaller system may be better for your needs.

Learn more about what size solar panel system you will need

Average amount of solar panels per system

Most solar panels from the main manufacturers are of a similar size, for example;

  • Yingli 48 cell series are 1310mm (l) x 990mm (w) x 40mm (h)
  • Canadian Solar Csp-p are 1638mm x 982mm x 40mm
  • Suntech Stp 265-20/Wen are 1640mm x 992mm x 35mm

Therefore you should need about the same amount of solar panels regardless of which manufacturer you choose. The table below suggests how many solar panels you should need, depending on the system you decide to install:

Typical System Size (kWh)
Typical number of panels
Typical roof area needed (sq m)

How many solar panels do I need calculator

Use our Solar PV calculator to determine which size solar panel system would be most suitable for your situation. This handy tool can show you the average cost of installation for each system size, along with potential savings and earnings over 20 years.

Start calculating here!

Spread the Word!