What Size Solar System Do I Need?

A simple starting point

System size is usually based on how much electricity your home uses.

Typical guide

~3—4kW system: £80—£120/month bill

~4—5kW system: £120—£180/month bill

~5—6kW system: £180+/month bill

What this means

  • Larger systems generate more electricity

  • But roof space and layout can limit what’s possible

Important to know

Most homes don’t aim to cover 100% of usage.

Instead, systems are designed to:

  • reduce grid reliance

  • improve long-term savings

  • work within the constraints of the property

Why this is usually unclear

In many cases, system size is only discussed once you’re already speaking to an installer.

We think it’s helpful to understand this earlier.

Final Note

This is a starting point — actual systems vary depending on your home, usage, and installation setup.

Most websites ask for your details before showing this — we think it’s more helpful to understand the basics first.