How much can solar panels save a UK home?

Avoided imports. Every unit you generate and use in the house is a unit you do not buy from your supplier. This is worth the full unit rate you pay, so it is the larger part of most households' savings.

Export payments. Surplus generation you do not use can usually be exported and paid for, depending on your supplier and export arrangement. Export rates are typically well below import rates, which is why using your own generation matters more than generating more of it.

Two identical systems on two identical roofs can save very different amounts. The difference is usually how much of the generation is used at home. Running dishwashers, washing machines, hot water and EV charging during daylight, or adding storage, raises that share.

If the house is empty on weekdays and most electricity is used in the evening, more of the generation gets exported at a lower rate, and the annual saving falls accordingly.

Our calculator and assessment take the details you give us — property type, roof direction and shading, household electricity spend and whether you are interested in a battery — and apply conservative, standard UK assumptions about annual generation per kWp and typical self-consumption.

The result is an indicative annual saving range. It is not a quotation and it is not guaranteed. Real savings depend on your actual tariff, your actual usage pattern, the specification an installer designs and the weather. Unit rates change over time, so any estimate should be treated as a snapshot based on the assumptions in front of it.

Be careful with anyone promising a guaranteed saving, a fixed payback, or a figure produced before anyone has looked at your roof or your consumption. A credible estimate always states its assumptions, and a credible installer confirms the design at survey.