A battery stores the sun you make at midday so you can use it at night. It's the difference between a system that saves you money and one that also keeps your lights on in a power cut. Whether it's worth it depends entirely on why you want one — and increasingly, on your tariff.
The money case
Batteries pay back fastest when paired with a time-of-use tariff. You charge from cheap overnight or midday solar and avoid the pricey peak-rate evening — and you stop exporting power for pennies when you could use it yourself. Where you're on a flat rate, the savings are thinner.
The peace-of-mind case
If power cuts are common or costly for you, a backup-ready battery recharges itself every morning. That value is real even when the spreadsheet is only lukewarm — and it's a big reason UK solar-plus-battery is the fastest-growing setup.
The quick version
- Batteries shine on time-of-use tariffs and high evening prices.
- They double as self-recharging backup power.
- 0% VAT applies to batteries until 31 March 2027.