How many solar panels do I need for my home? Your guide to solar array size

Most average-sized households will need between 8 and 13 solar panels to make a real difference to their energy bills. But your exact number depends on how much electricity you use, your roof size and orientation, and the type of panel you choose. For a bespoke system designed to meet your home’s energy needs, get in touch with us.

But if you’re considering adding solar to your home and would like a rough idea of how many panels you’ll need, we’ve put together a quick guide…

What decides how many solar panels you need?

A few factors work together to determine your final number:

Your household’s energy use, in kilowatt-hours (kWh), over a year
The wattage of the panels you choose – most domestic panels now sit between 350W and 450W
How much usable roof space you have, and which way it faces
How many hours of usable sunlight your area gets each day
Whether you’re adding battery storage, which changes how many panels make sense

How to work out your number: A step-by-step guide

The simplest way to estimate your panel count is to divide your daily electricity use by how much power each panel can realistically produce:

Daily electricity use (kWh) ÷ (panel size in kW × peak sun hours) = Number of panels needed

Let’s work through this with the average UK household. Ofgem’s current figures (as of July 2026) put typical annual electricity use at 2,500kWh, which works out at around 6.8kWh a day. However, panels rarely perform at their full rated output; cloud cover, shading and roof orientation all have an impact, so it’s sensible to add a buffer of around 25%, bringing daily need to roughly 8.5kWh.

Using a common 400W panel (0.4kW) and an average of 2.5 peak sun hours a day, each panel produces around 1kWh a day.

Divide 8.5kWh by 1kWh and you land on roughly 9 panels for an average home – a figure that lines up closely with what most UK homeowners install (see the table below).

Typical panel numbers by home size

Your own number will vary, but here’s a rough guide based on typical UK household sizes:

Home size	Typical annual usage	System size	*Panels needed**
1-2 bed	1,800-2,000 kWh	2-3kW	5-8
2-3 bed	2,500-3,350 kWh	3-4kW	8-10
3-4 bed	Around 4,000 kWh	4-5kW	10-13
Larger home, EV or heat pump	4,500 kWh+	6-8kW	15-20

*Example of 400W solar panel

These figures assume a well-positioned, south-facing roof with little shading. If your roof faces east or west, or has some shade for part of the day, you may need a few extra panels to reach the same output.

Why your roof affects the final number

South-facing roofs get the most consistent sunlight throughout the day, so systems here need fewer panels to hit the same output. East, west and even north-facing roofs still work well, though output can drop by around 15%, so it’s common to add a couple more panels to make up the difference. Chimneys, trees and neighbouring buildings can all cast shade during peak hours (typically 11am-3pm), which is why a proper site survey matters more than any online calculation.

Do you need more panels if you’re adding a battery?

Not necessarily. A battery doesn’t generate electricity, it stores what your panels already produce so you can use it later, such as in the evening. That said, if you want to become more energy self-sufficient, it’s worth sizing your panel system a little larger so there’s more surplus energy to store.

Ready to find your exact number?

These figures are intended to give you a guide, but the best way to find out exactly how many panels you’ll need is to contact us for a personalised quote. We’ll visit you to gain a proper understanding of your property, energy usage and goals, and design a system that’s tailored specifically to your needs.