August 14, 2026 · 5 min read · HSB Renewable Energy
A battery stores the excess your panels generate during the day and releases it when you actually need it. The number that matters is the share of your own generation you end up using rather than exporting, and a battery typically lifts that to around 70 to 80%.
That makes the biggest difference to households that use most of their power after dark. If everyone is out during the day and the house wakes up at six in the evening, most of what you generate is currently being exported for a fraction of what you pay to buy it back.
Batteries also open up cheap overnight tariffs. Several of our customers charge the battery overnight at the low rate and run the house from it through the darker winter months, which is a benefit that has nothing to do with the panels at all.
It does not always pay. If you are at home all day and already self-consume most of what you generate, the case is much weaker, and we will tell you so at the survey. If you already have panels, a battery can be retrofitted — including where you need to keep an existing FIT payment intact.
Want this checked in person?
A diagnostic visit is $89 and includes a full performance test with the readings shown to you. Call 01244 952496 or request a window online.