Choosing a solar system size

Kilowatts (kW) describe the capacity of the array, not a guaranteed annual saving. A 4kW system on a shaded north-east roof will not behave like a 4kW system on an unshaded south-facing roof. That is why we survey before we recommend a size.

A simple way to think about it

2kW to 3kW. Often suits smaller roofs, lower daytime use, or a first install where budget and space are limited.

4kW to 6kW. A common range for family homes with reasonable roof area, especially where daytime use is steady or an EV or heat pump is planned.

Larger arrays. Commercial roofs, outbuildings, and some larger homes need a design that also considers the electrical supply and DNO limits. These are quoted individually.

Our installation packages set out 2kW to 6kW options. They are starting points. If the survey says a different size is the better fit, that is what we will recommend.

What actually decides the number

• Usable roof area, pitch, and orientation
• Shading through the year
• Your electricity use, and any near-term changes
• Consumer unit capacity and whether the DNO needs to approve the connection
• Whether you want battery storage now or later

After you choose

You receive a layout, equipment schedule, predicted generation, and an itemised price. Predicted generation is an estimate based on the survey, not a promise of bills or payback.

If you already have a size in mind, tell us when you book a survey. We will check it against the roof rather than assume it is right.