How much could solar save you?

What panels really make in our weather, how much of it you use, and why the typical figures are a range, not a promise.

Everyone wants a number. Here is how we get to one, and why it’s always a range.

What the roof makes

On a south-facing roof in the vale, each kWp of panels makes about 950 kWh a year. East or west, about 80% of that. A 4 kWp system therefore makes roughly 3,800 kWh: more in a sunny year, less in a dull one.

How much you use yourself

This is the part that changes the answer most. A home that’s empty all day might use 30% of what the panels make; one with someone home, or a battery, 60% to 80%. Every unit you use saves you what you’d pay for it, about 27p today. Every unit you export earns the export rate, often 15p or less.

Putting it together

For a typical 4 kWp system, that comes to £520 to £760 a year. Add a battery and it’s typically another £240 to £420. These are typical figures, not promises: prices change, the weather varies, and so do households.

Try the calculator for your own estimate, and book a free survey for a proper one.