Solar battery price FAQs

DESNZ publishes medians rather than a single average. For 2025/26 the middle installed price was £1,300 per nominal kWh under 6 kWh, £890 for 6 to 11 kWh and £630 for 11 kWh and over. On those figures a 5 kWh battery comes to about £6,500 fitted and a 13.5 kWh battery to about £9,400, at 0% VAT (to 31 March 2027).

Much of an installation costs the same whatever the battery's size: the visit, cabling, protection, commissioning, the certificate and the network paperwork. Spread over fewer kWh, those fixed costs raise the price per kWh, which is why the under-6 kWh band has the highest median.

Nominal. MCS records the battery's nominal storage capacity and DESNZ prices against it. If a battery lets you use less than its label, its price per usable kWh is higher than any official figure.

Start from the evening and night use you want to cover, not from the biggest size on offer. Ofgem's typical medium-use home uses 2,500 kWh a year on a single-rate meter, about 6.8 kWh a day. Price the usable size that covers the part of that you want shifted, and remember solar fills a battery far less in winter.

Not for every size. Between 2024/25 and 2025/26 the median rose about 20% for batteries under 6 kWh, fell about 2% for 6 to 11 kWh and rose about 7% for 11 kWh and over, while the number recorded rose 82%.

Divide the total by the battery's nominal kWh and compare it with the official median for its size band. Above the median, ask for the quote to be itemised; below it, ask what is left out. The quote checker on the price per kWh page does the sum.

Mainly where the battery has to go (fire-resisting separation, ventilation, alarms and impact protection under PAS 63100), the inverter work, any backup for power cuts, the network application and the certificates. None has an official price, so ask for each as a line.

It can. With existing panels an AC-coupled battery usually keeps your solar inverter and adds its own, while a DC-coupled system usually replaces it with a hybrid inverter. Which?, citing the Energy Saving Trust, says AC systems tend to cost more, without giving figures.

Usually. A battery that keeps circuits running while the grid is down needs switching so it can supply the home safely in isolation. Ask for the backup hardware priced separately and for the list of circuits it covers.

It can be: one visit and one round of paperwork cover both, and Which? reports that several large suppliers discount a battery bought with panels. There is no official figure for the difference, because DESNZ prices batteries and panels in separate series.