Short answer: It can be, if you are on a time-of-use tariff with cheap overnight electricity and use a lot in the evening. The battery charges cheaply at night and runs the house at peak times. On a flat-rate tariff it saves very little. In Derby, batteries cost £4,317 to £7,434 on Checkatrade's figures.
How a battery saves money without panels
Without solar panels, a home battery works on the difference between electricity prices at different times of day. On a time-of-use tariff, electricity is much cheaper for a few hours overnight. The battery charges then and supplies the house through the evening, when you would otherwise pay the full rate.
On a flat-rate tariff there is no gap to use, so a battery on its own saves almost nothing. The whole case depends on the tariff.
Working out the saving
Take the price you pay for daytime or evening electricity and subtract the overnight price. That is roughly what each unit shifted by the battery saves, less a small loss for charging and discharging. Multiply by how many units you use in the evening, up to the battery’s usable capacity, and by the days in a year.
For comparison, the East Midlands price cap is 25.36p per kWh for 1 October to 31 December 2026 (Ofgem). Time-of-use tariffs set their own cheaper overnight rates, which vary by supplier, so check your own tariff before relying on any figure.
What it costs in Derby
Checkatrade lists solar battery storage in Derby at £4,317 to £7,434, averaging £5,640 (Checkatrade). HMRC’s VAT notice includes batteries among the energy-saving materials zero-rated in homes until 31 March 2027, and says stand-alone electrical storage batteries in residential accommodation qualified from 1 February 2024 (HMRC VAT Notice 708/6). Ask for the VAT treatment to be shown on the quote.
Thinking about a battery?
We size it from your meter data, with or without panels. Call for a free quote.
When adding solar is the better move
A battery charged only from the grid depends entirely on the tariff gap. With panels as well, it also stores free daytime power. PVGIS gives a south-facing Derby roof about 979 kWh per kWp a year (PVGIS), most of it from spring to early autumn, so in summer the battery can often be filled from the roof and in winter from cheap overnight rates.
If your roof faces south, east or west and isn’t heavily shaded, it is worth pricing panels and a battery together. The scaffold, survey and electrical work are shared, and a single hybrid inverter can run both. Solar battery storage covers the options, and How much do solar panels cost in Derby? covers the panels.
Who a battery-only setup suits
A battery without solar tends to suit homes with a north-facing or heavily shaded roof, flats without roof access, and households on a time-of-use tariff who use a lot of electricity in the evening, such as those with an electric car or electric heating. For most houses with a usable roof, panels and a battery together make a stronger case.
Bottom line
A battery without solar only pays if your tariff has a big gap between cheap overnight and daytime prices and you use a lot in the evening. Batteries in Derby cost £4,317 to £7,434 on Checkatrade's figures, with 0% VAT. If you have a suitable roof, adding panels usually improves the numbers. Call 01332 919162, 9am to 7pm, 7 days.