Solar Battery Storage Guide 2026
Battery storage transforms a good solar investment into a great one. Store surplus energy, eliminate export at low rates, and keep your lights on during power cuts.
Why Add Battery Storage to Solar?
A solar panel system without battery storage exports surplus electricity to the grid at low SEG rates (typically 3–15p/kWh) and then buys electricity back in the evening at full retail price (24–28p/kWh). A battery closes this gap by storing your own solar electricity for use when the sun is not shining.
With a battery, a typical 4kW solar system with 9.6kWh storage can achieve 80–90% self-sufficiency throughout summer months. The additional cost of a battery is typically recovered in 5–7 years through avoided import costs.
Solar Without Battery vs Solar With Battery
| Solar Without Battery | Solar With Battery |
|---|---|
| Surplus exported at 3–15p/kWh | Surplus stored for evening use |
| Evening power purchased at 24–28p/kWh | Very little evening grid import |
| Self-consumption: 30–50% | Self-consumption: 80–90% |
| Lower upfront cost | Backup power in outages (some models) |
Battery Comparison 2026
All prices include installation and 0% VAT. Supplied and installed by Midland Solar.
| Battery | Capacity | Max Power | Warranty | Installed Price | Notes |
|---|---|---|---|---|---|
| Fox ESS EP5 | 9.5kWh | 5kW | 10 years | £3,800–£4,800 | Best value for most homes |
| Tesla Powerwall 3 | 13.5kWh | 11.5kW | 10 years | £8,500–£10,000 | Premium — ideal for EV owners |
| Fox ESS ECS2900 | 9.6kWh | 3kW | 10 years | £3,200–£4,200 | Reliable, competitive pricing |
| SIG Energy | 10kWh | 5kW | 10 years | £3,500–£4,500 | Excellent UK-supported system |
| Solis RHI-3P | Up to 20kWh | 10kW | 10 years | £5,000–£8,000 | Ideal for larger homes |
How to Choose the Right Battery Size
| Household | Daily usage | Recommended battery | Ideal solar |
|---|---|---|---|
| 1–2 people | 6–8 kWh/day | 5–9.6 kWh | 3–4 kW |
| 3–4 people | 10–14 kWh/day | 9.6–14.4 kWh | 4–6 kW |
| 5+ people | 15–20+ kWh/day | 14.4–20 kWh | 6–10 kW |
Frequently asked questions
How much does a home battery storage system cost in the UK?
Home battery storage systems typically cost between £2,500 and £10,000 in the UK, depending on capacity. A 9.6kWh Fox ESS battery costs approximately £3,500–£4,500 installed. A 14.4kWh system costs £4,500–£6,500. When combined with a solar installation, batteries often attract package discounts.
How long does a home battery last?
Most modern home batteries are rated for 6,000–10,000 charge cycles and come with 10-year warranties. In normal use (one full charge-discharge cycle per day), this equates to 16–27 years of service life. In practice, batteries typically last 12–15 years before needing replacement.
What size battery do I need?
The right battery size depends on your daily energy consumption and solar system size. For a typical UK home using 10–15 kWh per day with a 4kW solar system, a 9.6–14.4 kWh battery is usually sufficient to store the surplus from a sunny day. We size batteries precisely to your usage pattern during our survey.
Can I add battery storage to an existing solar system?
Yes — battery storage can be retrofitted to most existing solar installations. Depending on your current inverter, we may need to install a hybrid inverter alongside the battery. Midland Solar installs battery storage retrofits regularly and can assess compatibility with your existing system.
Do battery storage systems qualify for 0% VAT?
Yes — since February 2024, standalone battery storage systems (without solar panels) qualify for 0% VAT when installed in a residential property. Previously, the 0% rate only applied to batteries installed alongside solar panels. This has made battery-only retrofits significantly more cost-effective.
Which battery is best — Tesla Powerwall or Fox ESS?
Both are excellent systems. The Tesla Powerwall 3 is premium-priced but integrates with Tesla EVs and solar exceptionally well. Fox ESS offers excellent performance at a competitive price point. We recommend the right system for your needs during your free survey.
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Complete solar & battery packages
Fixed prices, supply and installation included. Every package is MCS certified and comes with our 2-year workmanship guarantee.
- 3.84kW · 8 panels£5,995
- 8 × LONGi 480W all-black
- Fox ESS 3.68kW hybrid inverter
- Fox ESS EP6 — 5.76kWh storage
- 5.76kW · 12 panels£6,995
- 12 × LONGi 480W all-black
- Fox ESS 5.0kW hybrid inverter
- Fox ESS EP6 — 5.76kWh storage
- 7.68kW · 16 panels£7,995
- 16 × LONGi 480W all-black
- Fox ESS KH7 hybrid inverter
- Fox ESS EP6 — 5.76kWh storage
Upgrade any package to the Fox ESS EP12 (11.52kWh) for £995.
All package prices assume every panel fits on a single roof elevation. The price covers the cost of scaffolding to one elevation. If your roof needs scaffolding on more than one elevation, or has restricted access, that additional cost is quoted separately after survey. Prices include VAT. Domestic solar and battery storage is zero-rated for VAT until 31 March 2027. Subject to a free technical survey. We will confirm the final price in writing before any work is booked.