Is a battery worth adding to solar panels?
Not sure? Ten panels in southern England make roughly 3,800 kWh a year, and a typical home uses about 2,700 kWh. The solar panel calculator can estimate yours.
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best value battery
| Battery | Solar used | Extra a year | Cost | Payback |
|---|
Battery costs follow typical 2026 UK prices fitted, at 0% VAT. Batteries usually last 10 to 15 years, so a payback much longer than that may not be worth it.
Battery guide: when a battery pays
What a battery does
Without a battery, solar electricity you don’t use straight away goes to the grid, and you’re paid an export rate, often around 12p per kWh. A battery keeps it for the evening instead, when it saves you the full price of about 26p. The battery earns the difference between the two.
When it pays off best
Batteries make most sense when you’re out in the day, export a lot and use a lot in the evening. If you’re home most of the day, you already use much of your solar, so a battery adds less.
Cheap night-time electricity
Some energy tariffs offer much cheaper electricity overnight. A battery can charge from the grid at night and power your home during the expensive hours, which can add more savings, especially in winter. This calculator only counts solar savings, so it’s on the cautious side.
Size
Bigger isn’t always better. A battery larger than your spare daily solar sits half empty for much of the year. Look at the table: the size with the shortest payback is usually the sensible choice.