Solar panels: the honest calculation behind the 'will they pay back?' question

Solar savings depend on your roof orientation, your usage patterns, whether you have a battery, and whether you're at home during the day. The best-case figures in brochures assume south-facing roofs, high daytime occupancy, and perfectly matched consumption. Most homes are not the best case.

For a typical UK semi-detached home with a south or south-west facing roof, a 4kW system will generate around 3,400–3,800 kWh per year. How much of that you actually use depends on when you're home — and whether you have a battery to store what you don't use immediately.

We always provide realistic generation estimates at survey stage, based on your specific roof orientation and shading profile. If the numbers don't work for your situation, we'll say so.