Solar battery storage cost when panels and battery go in together
A solar-plus-battery quote is two prices in one. The government publishes them as two separate series, so the fairest way to judge a combined quote is to split it the same way.
Quick answer
On DESNZ's figures for batteries registered with MCS, the battery part of a solar-plus-battery job should benchmark at about £6,500 for 5 kWh and about £8,800 for 10 kWh at 0% VAT (to 31 March 2027). Those figures leave the panels out; DESNZ prices panels in a separate series that leaves batteries out. Ask for the battery as its own line and compare each half with its own figure.
Two official series, one quote
DESNZ publishes the cost of home batteries and the cost of solar panel systems separately, and each one carefully excludes the other. The battery statistics count the battery, fitting it and connecting it, and say that additional devices such as solar panels installed alongside are not included. The solar PV cost data, also published on 28 May 2026, include the equipment, installation and connection of the panels and exclude batteries.
That is helpful for a buyer. A combined quote that shows panels and battery as one total can't be checked against either series. A quote that separates them can: the battery line against the battery medians, the panel line against the panel figures. This site covers the battery half; for the panel half, use the DESNZ solar PV cost data directly.
| Line on the quote | Benchmark it against | Watch for |
|---|---|---|
| Panels, mounting kit and fitting | DESNZ solar PV cost data | Access equipment shown separately or folded in |
| Battery, fitting and connection | DESNZ battery medians: £1,300, £890 or £630 per nominal kWh by size | Nominal or usable kWh on the quote |
| Hybrid inverter | Neither series cleanly: ask for it as its own line | Whether it has been counted in both halves |
| Network application | No official price | Who submits it and when (usually G99 for a combined system) |
| Battery siting works | No official price | Fire-resisting separation, ventilation, alarms, impact protection |
| Backup for power cuts | No official price | Which circuits it covers |
Why fitting both together can cost less, and when it doesn't
One visit, one set of access equipment, one consumer-unit job and one round of paperwork can cover both installations. Which? also reports that several large suppliers offer a discount when a battery is bought with panels, though it gives no figure. Put together, a battery fitted with new panels can come in under the retrofit benchmark.
It doesn't always. A combined system often uses a single hybrid inverter sized for both, and the network operator sees the two as one connection: MCS notes that solar plus battery is likely to exceed the G98 limit of 16 A per phase, so a G99 application before installation is the usual route. That application can add a wait and come with conditions. And the battery still has to go somewhere that meets PAS 63100, which a new array does nothing to help with.
If you are weighing whether to add the battery now or later, compare the battery line on your quote with what adding a battery to existing panels costs. If the difference is small, timing matters less than getting the size right.
VAT on a panels-plus-battery job
Installed solar panels and installed home batteries are both energy-saving materials under HMRC Notice 708/6, so both are zero-rated until 31 March 2027 and charged at 5% from 1 April 2027. Which rate applies turns on the dates of the invoice and payment for the work, not when you first asked for a quote; the VAT page explains deposits and invoice dates. If the job also includes building work that isn't an energy-saving material, such as replacing roof tiles, that part can carry a different rate.
Sizing a battery to panels you haven't fitted yet
A battery fed by solar can only store what the panels produce beyond what the house uses at the time. With new panels you have no export history to go on, so the installer's estimate is the starting point. Installers registered with MCS use a lookup-table method for how much solar a home uses itself; a secondary source notes it does not cover batteries over 15.1 kWh or homes using under 1,500 or over 6,000 kWh a year.
Location matters too. The European Commission's PVGIS tool puts a year's output per kWp of panels, tilted at 35 degrees and facing south, at about 814 kWh in Bangor, 965 kWh in Liverpool and 1,042 kWh in Cardiff. Winter days produce a fraction of summer ones: at Leicester, about 3.9 kWh per kWp a day in June against 1.1 in December. Price the usable battery size that covers the evening use you care about, and expect it to fill far less often in winter. Then test it in the year-one bill effect guide with your own tariff.
Getting a combined quote you can actually compare
- Ask for panels, inverter and battery as separate lines, with the battery's nominal and usable kWh.
- Ask which network application the installer will make, and whether the date they offer allows for the reply.
- Ask where the battery will go and what the siting work costs as its own line.
- Check the firm on the MCS register for both solar PV and battery storage: they are separate certifications.
- Check the battery line with the quote checker.
If the quote is for a large battery, read the large battery price page first: storage limits per enclosure and per home start to matter above 20 kWh.
Solar and battery price questions
Is a battery cheaper if it goes in with new panels?
It can be. Which? reports that several large suppliers discount a battery bought with panels, and one visit, one set of access equipment and one round of paperwork cover both jobs. There is no official figure for the difference, so get the battery priced on its own line and compare it with the retrofit figures.
What VAT applies to solar panels and a battery fitted together?
Both are energy-saving materials when installed in a home, so both are zero-rated until 31 March 2027 and charged at 5% from 1 April 2027. A mixed job that includes other building work, such as re-roofing, can carry different rates on those parts.
Which inverter goes on the battery line?
With a hybrid inverter there is one unit doing both jobs, and quotes split it differently. Ask the installer to show the inverter as its own line, so you can benchmark the battery and panel parts fairly.
Sources (page last reviewed 3 November 2026)
- DESNZ: MCS certified domestic battery installation statistics (April 2024 to March 2026 workbook, published 28 May 2026), checked 3 November 2026.
- DESNZ: solar PV cost data (2025/26, published 28 May 2026; excludes batteries), checked 19 October 2026.
- HMRC: VAT on energy-saving materials and heating equipment (Notice 708/6), sections 2.1, 2.3 and 2.19, checked 3 November 2026.
- Which?: solar panel battery storage (secondary source, page updated 30 October 2026), checked 3 November 2026.
- MCS: notifying distribution network operators (G98 and G99), checked 3 November 2026.
- MCS: find an installer (the public register), checked 3 November 2026.
- BSI / DESNZ: PAS 63100:2024, battery energy storage systems in dwellings (PDF), checked 3 November 2026.
- European Commission JRC: PVGIS solar yield tool, checked 30 October 2026.
- Easy PV help: limits of the MCS self-consumption lookup method (secondary), checked 3 November 2026.
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