A home battery is now the single biggest variable in a UK solar quote. Panels have largely commoditised; storage has not. The honest national benchmark in 2026 is £700–£950 per usable kWh installed, all-in — hardware, inverter or hybrid inverter, cabling, protective devices, commissioning and certification. Anything materially below that band usually means a smaller usable capacity than advertised, a stripped-back electrical scope, or a warranty that will not outlive the payback period.
This page sets out what batteries actually cost by capacity, what pushes a quote up or down, how the 0% VAT window changes the maths, and how to compare three quotes that look superficially identical. Every figure below is an indicative range, not a fixed price — only a site survey produces a real number.
Coverage band: where we install, and what to do if you are outside it
YEERS is a Hull-based MCS-certified installer covering Hull, Yorkshire and Lincolnshire. Every price on this page reflects real installation work in that area. If your property sits outside Hull, Yorkshire or Lincolnshire, the cost guidance still applies nationally — but please use the MCS Find an Installer directory to source a certified installer local to you rather than requesting a quote from us. MCS certification is a hard requirement if you intend to claim the Smart Export Guarantee, so it is worth filtering on it from the start.
Solar battery cost by capacity (UK, 2026)
Figures below are installed costs including VAT at 0%, for a standard retrofit or solar-plus-storage install with no unusual access or distribution-board complications.
| Usable capacity | Indicative installed cost | Cost per usable kWh | Typical home | Indicative annual saving |
|---|---|---|---|---|
| 5 kWh | £4,250 – £4,750 | £850 – £950 | 1–2 bed, low evening load, no EV | £220 – £420 |
| 10 kWh | £7,000 – £9,000 | £700 – £900 | 3–4 bed family, 3,500–4,500 kWh/yr | £450 – £800 |
| 15 kWh | £10,500 – £13,000 | £700 – £867 | 4–5 bed, one EV | £650 – £1,150 |
| 20 kWh | £14,000 – £17,000 | £700 – £850 | Large home, EV plus heat pump | £850 – £1,500 |
| 30 kWh | £21,000 – £24,000 | £700 – £800 | Rural / high-load / whole-home backup | £1,200 – £2,100 |
Two things fall out of that table. First, cost per kWh falls as capacity rises — the inverter, the electrical work and the labour day are largely fixed, so they are spread over more storage. A 5 kWh unit sits at the top of the £700–£950 band; a 20–30 kWh stack sits at the bottom of it. Second, saving does not scale linearly. A battery only earns when it is cycled, so oversizing beyond your daily consumption plus off-peak charging appetite adds capital without adding return.
Retrofit vs installed with solar: DC-coupled and AC-coupled
If the battery goes in at the same time as the panels, it can be DC-coupled behind a single hybrid inverter. One inverter, one commissioning visit, one round of electrical work. If you already have solar and a working string inverter, the usual route is an AC-coupled retrofit: a separate battery inverter sits alongside the existing one.
| DC-coupled (with new solar) | AC-coupled (retrofit) | |
|---|---|---|
| Typical premium on a 10 kWh install | Baseline | +£600 – £1,200 |
| Round-trip efficiency (typical) | ~92–96% | ~88–92% (extra conversion step) |
| Existing inverter | Replaced by hybrid | Retained |
| Best for | New systems, whole-home backup | Solar already installed, inverter still in warranty |
A third option now exists: replacing an ageing string inverter with an all-in-one hybrid unit at retrofit time. Sigenergy's SigenStor packages inverter and modular battery (5–48 kWh) in one enclosure with roughly a 15-year warranty and genuine whole-home backup; Solax Triple Power builds capacity in around 5.8 kWh units with roughly a 10-year warranty, and is the value pick, though it locks you into the Solax hybrid inverter ecosystem. We compare the two head to head in Sigenergy vs Solax, and the wider field — GivEnergy (UK-made, strong installer network, ~12 years), Fox ESS (value), Tesla Powerwall 3 (13.5 kWh with integrated inverter) and Sunsynk hybrids — in best solar batteries UK 2026.
What actually drives the price
- Inverter — the largest single non-battery line. A hybrid or all-in-one unit typically adds £1,200–£2,500 versus reusing an existing inverter.
- Cabling run — a garage battery 3 m from the consumer unit is cheap. A loft or outbuilding installation 20 m away, through masonry, adds labour, containment and cable cost, commonly £300–£900.
- Consumer-unit work — older boards frequently need a new dedicated way, an upgraded board, or a backup sub-board for essential circuits: £250–£1,400.
- Scaffolding — irrelevant for a standalone battery, but £600–£1,500 on a combined solar-and-battery job depending on roof access and storeys.
- Battery chemistry and build — LFP dominates domestic storage for cycle life and thermal safety. Warranty length, guaranteed end-of-life capacity and cycle count matter more to lifetime cost than the headline kWh price.
- Backup capability — true whole-home backup needs an automatic changeover and, often, additional board work. Budget £400–£1,200 above a grid-tied-only install.
0% VAT until 31 March 2027 — the worked saving
Domestic solar, battery storage (including standalone batteries since February 2024) and heat pumps carry 0% VAT until 31 March 2027, reverting to the 5% reduced rate afterwards. Note the date: several sites still quote 31 January, which is wrong — HMRC VAT Notice 708/6 is the authority.
Worked example on a £9,000 10 kWh install: today the invoice is £9,000. From 1 April 2027 the same job is £9,450 — a £450 saving for installing inside the window. On a £17,000 20 kWh system the difference is £850. That is not a reason to buy a system you do not need, but it is a real reason not to defer one you do.
Batteries are not eligible for the Boiler Upgrade Scheme (£7,500 towards an air source heat pump in England and Wales, claimed on your behalf by the MCS installer). Some households may access ECO4 LA Flex through their local council until 31 March 2026; eligibility is means- and property-tested and rarely covers storage alone.
Payback: SEG plus off-peak arbitrage
Battery returns come from three places: storing your own solar instead of exporting it, charging cheaply overnight and discharging at peak, and exporting under the Smart Export Guarantee. SEG rates are indicative and supplier-dependent, spanning roughly 1p to 27p/kWh — Octopus is consistently the strongest — and claiming SEG requires MCS certification plus a working smart meter.
A 10 kWh battery with about 9 kWh usable, cycled roughly 300 days a year on a tariff with a ~20p/kWh spread between night and peak rates, produces in the region of £540 of arbitrage before any solar contribution. Add self-consumption of solar that would otherwise export at a low rate and £700–£800 a year is realistic for a 3–4 bed home. Against an £8,000 cost that is a 10–11 year payback, shortening to around nine years for households that shift heavy loads (EV, immersion, heat pump) into the battery window. Treat any quote promising a sub-six-year battery payback with real scepticism unless the arithmetic is shown in full.
How to compare quotes properly
- Normalise to cost per usable kWh, not nominal capacity. A "10 kWh" battery with 9.0 kWh usable is a different product from one with 10.0 kWh usable.
- Compare warranty on the same basis: years, throughput or cycles, and guaranteed remaining capacity at end of term (commonly 70–80%).
- Confirm MCS certification and DNO notification are included — without them your SEG application stalls.
- Ask what is excluded: consumer-unit upgrade, scaffolding, backup changeover and long cable runs are the four most common post-survey additions.
- Check the workmanship warranty separately from the product warranty. Ours is 10 years.
- Insist on a written saving calculation naming the tariff, the spread and the assumed number of cycles.
If you are in Hull, Yorkshire or Lincolnshire and want a costed, survey-backed figure rather than a range, request a quote through our online form and we will size the system against your actual half-hourly consumption. Full scope and process is set out on our battery storage installation page.
Frequently asked questions
How much does a 10kWh solar battery cost to install in the UK in 2026?
Expect £7,000–£9,000 installed for a 10 kWh usable system, equivalent to £700–£900 per usable kWh including the inverter, electrical work, commissioning and MCS certification. Retrofits onto an existing solar array typically sit £600–£1,200 higher than the same battery installed at the same time as new panels, because AC coupling needs its own battery inverter. All figures are indicative ranges and vary with site conditions and hardware choice.
Is a solar battery worth it without solar panels?
It can be, but the return comes from tariff arbitrage rather than solar. A standalone battery charges on a cheap overnight rate and discharges at peak; on a roughly 20p/kWh spread, a 10 kWh unit with about 9 kWh usable, cycled around 300 days a year, saves in the region of £540. Standalone batteries have qualified for 0% VAT since February 2024, which helps the maths. Without solar you forgo Smart Export Guarantee income, so payback is usually longer than for a combined system.
Do I still pay VAT on a solar battery in 2026?
No. Domestic solar, battery storage including standalone batteries, and heat pumps carry 0% VAT until 31 March 2027, after which the 5% reduced rate returns. Some sites incorrectly state 31 January; HMRC VAT Notice 708/6 is the correct reference. On a £9,000 installation that window is worth £450.
Can I add a battery to an existing solar PV system?
Yes. The standard route is an AC-coupled retrofit, where a separate battery inverter works alongside your existing string inverter. Round-trip efficiency is a few percentage points lower than DC coupling because of the extra conversion step, and the cost premium is typically £600–£1,200. If your existing inverter is near end of life, replacing it with an all-in-one hybrid unit is often better value than paying for a second inverter.
What is the payback period on a home battery?
For a 3–4 bed home with a 10 kWh battery at around £8,000, saving £700–£800 a year through off-peak charging, solar self-consumption and SEG export, payback lands at roughly 10–11 years. Households that shift an EV, immersion heater or heat pump into the battery window can bring that closer to nine years. Be sceptical of any quote claiming payback under six years unless the calculation is shown in full.
Do I need an MCS-certified installer for a battery?
You do if you want to claim the Smart Export Guarantee, which requires MCS certification and a working smart meter. MCS also underpins most manufacturer warranty terms and gives you a recognised route for complaints. YEERS is MCS-certified and installs across Hull, Yorkshire and Lincolnshire; if your property is outside that area, use the MCS Find an Installer directory to find a certified installer local to you.
Last updated August 2026 · YEERS — MCS-certified installers, Hull & Yorkshire.
