What could solar save you?
Slide in your monthly bill for a rough system size, yearly saving and payback — no sign-up, no spam.
A rough guide based on UK averages (≈900 kWh per kWp per year for a well-sited roof, 26p import on the Ofgem cap, 10p SEG export). Your real numbers depend on your roof, tariff and usage — an MCS installer’s survey is the only true figure.
About this calculator
How accurate is this solar savings calculator?
It's a rough guide based on UK averages — roughly 900 kWh per kWp per year for a well-sited roof, a 26p import price (the Ofgem price cap for July–September 2026) and a 10p export rate. Your real figures depend on your roof orientation, shading, tariff and how much electricity you use during the day. Treat it as a starting point; an MCS installer's survey gives the only firm numbers.
Does a battery improve solar savings?
Usually, yes. A battery lets you use more of the solar you generate (around 70% instead of 40%) and dodge expensive peak-rate evening electricity, especially on a time-of-use tariff. The calculator lets you toggle a battery on and off to see the difference.
Is the 0% VAT included?
The indicative system cost shown assumes the current 0% VAT on qualifying residential solar and battery installs, which is scheduled to end on 31 March 2027. From 1 April 2027 the rate is set to return to the reduced 5% rate (not the standard 20%).