Solar panels are an obvious upgrade. Whether to add a battery is the harder question. By 2026 there are five or six battery brands genuinely worth considering for UK homes — and the differences between them matter more than most installer websites admit.
This guide walks through what a solar battery storage system actually does, when it’s worth it, and how the major UK brands compare in 2026.
What does a solar battery actually do?
Solar panels generate most of their electricity in the middle of the day. Most households use most of their electricity in the morning and evening. Without a battery, the gap means you either:
- Use it now or lose it — surplus daytime generation gets exported to the grid at SEG rates (4–15p/kWh)
- Buy it back at peak rates — your morning kettle and evening cooker run on imported grid electricity at 28–34p/kWh
A solar battery bridges that gap. Generation goes into the battery during the day. You use it from the battery in the morning, evening and overnight. Self-consumption goes from typically 30–40% (no battery) to 70–90% (with battery).
Is a battery worth it?
For most Sussex households with daytime occupancy patterns that don’t already match solar generation, yes. The payback period for a battery is typically 6–10 years in 2026 conditions, on top of the solar payback.
The case is strongest when:
- You use 4,000+ kWh of electricity a year
- You’re at home in the evenings (most peak use happens then)
- You drive an EV or are considering one — pair with an EV charger and the maths gets really attractive
- You want backup power during outages (some batteries do this, see EPS section below)
- You’re worried about grid electricity price rises (batteries hedge against them)
How much do solar batteries cost in 2026?
A home battery typically costs £3,000–£6,000 fully installed depending on capacity and brand. Most households benefit from a 5–10 kWh battery.
| Capacity | Suits a household using | Indicative installed price 2026 |
|---|---|---|
| 5 kWh | 2,500–4,000 kWh/year | £3,000 – £4,000 |
| 10 kWh | 4,000–6,000 kWh/year | £4,500 – £6,000 |
| 13.5 kWh (Powerwall) | 5,000–8,000 kWh/year | £8,000 – £10,000 |
| 15+ kWh (stacked) | 6,000+ kWh/year | £6,500 – £9,000 |
The major brands in 2026
Tesla Powerwall 3
The headline-grabbing option. 13.5 kWh capacity, built-in inverter (replaces or supplements your solar inverter), 11.5 kW continuous power output. Tesla Powerwall 3 sells itself partly on the brand and partly on the EPS backup feature — it can power your whole home through a blackout, not just essential circuits.
- Strengths: high power output, whole-home EPS backup, app is very polished, scaleable up to 4 units
- Weaknesses: price-per-kWh isn’t competitive at lower capacities; 10-year warranty (industry standard but no longer)
- Typical fully-installed cost: £8,000–£10,000
- Best for: larger households (4+ people), homes with regular power outages, EV owners
GivEnergy All-in-One
Often the highest-value option for UK homes in 2026. 13.5 kWh capacity, hybrid inverter included, 6 kW power output. GivEnergy is UK-based, the support is excellent, and the price-per-kWh undercuts most rivals.
- Strengths: best value at 13.5 kWh, 12-year warranty (better than industry), UK company with strong support, app is excellent
- Weaknesses: EPS backup is essential-circuits only by default (not whole-home), 6 kW output is plenty for most homes but lower than Powerwall
- Typical fully-installed cost: £6,500–£8,500
- Best for: Most UK homes — strong all-rounder that’s hard to beat on value
SolarEdge Home Battery
Strong choice if you already have a SolarEdge inverter (or are getting solar + battery as a combined install). 10 kWh modular system, scalable. SolarEdge optimises panel-level performance so it shines when partial shading or complex roofs are involved.
- Strengths: excellent panel-level optimisation, modular and scalable, integrates seamlessly with SolarEdge solar
- Weaknesses: only really makes sense if you’re using SolarEdge for solar too; ecosystem lock-in
- Typical fully-installed cost: £5,500–£7,500 for 10 kWh
- Best for: complex roofs, shaded panels, homes wanting a single-vendor ecosystem
Sigenergy SigenStor
Newer entrant gaining traction in 2026. Modular (5 kWh blocks), AC-coupled, fits well with existing solar systems. Becoming popular for retrofit batteries where you don’t want to change your solar inverter.
- Strengths: excellent for retrofit, scalable in 5 kWh increments, fast EV charging integration
- Weaknesses: newer brand so less long-term track record
- Typical fully-installed cost: £4,500–£6,500 for 10 kWh
- Best for: Adding a battery to existing solar without replacing the solar inverter
FOX ESS / Solis / Growatt
Budget-friendly options at the lower end. 5–10 kWh capacity, often the cheapest installed price. Brand maturity and support quality vary. Worth considering if budget is tight but check the local UK support before buying.
- Typical fully-installed cost: £3,500–£5,500
- Best for: Cost-conscious installs, smaller households
EPS / backup power during outages
Grid-tied solar PV automatically shuts down during a power cut for safety reasons. That feels counter-intuitive (“my panels are working and I can’t use them”) but it’s how the regulations work — you can’t backfeed power into the grid while engineers might be working on it.
Battery systems with EPS (Emergency Power Supply) get around this. They isolate your home from the grid during an outage and continue running essential circuits — or the whole home in some cases — from the battery.
EPS comparison at a glance:
| Battery | EPS / backup | Whole-home or essential circuits |
|---|---|---|
| Tesla Powerwall 3 | Yes | Whole-home (with right install) |
| GivEnergy All-in-One | Yes | Essential circuits (whole-home optional) |
| SolarEdge Home Battery | Yes | Essential circuits |
| Sigenergy SigenStor | Yes | Essential circuits |
| FOX ESS / Solis / Growatt | Varies by model | Usually essential circuits |
Retrofit vs new install
Adding a battery to existing solar panels is straightforward in most cases. We assess your existing inverter and consumer unit during a free site survey. An AC-coupled battery (like SigenStor or GivEnergy All-in-One) works alongside your existing solar inverter without needing to replace it.
If you’re getting solar and battery together as a single install, a hybrid inverter (one box for both) is typically the most cost-effective option — GivEnergy and SolarEdge both do this well.
Bottom line: which battery should you choose?
- Best all-round value — GivEnergy All-in-One
- Best for power outages and whole-home backup — Tesla Powerwall 3
- Best for complex/shaded roofs — SolarEdge Home Battery
- Best for retrofit to existing solar — Sigenergy SigenStor
- Best on a tight budget — FOX ESS or Solis
Whichever brand, the install matters as much as the kit. A battery that’s wrongly sized, configured for the wrong tariff, or installed without EPS planning won’t deliver what it should. We size and configure every battery installation individually.
Related guides
- Our Battery Storage Service — MCS certified battery installation across Sussex.
- Solar Panel Cost Guide UK 2026 — Including battery storage pricing.
- Solar + EV Charging — How pairing solar with a battery and EV charger compounds your savings.
