Battery storage significantly improves solar ROI by storing excess daytime generation for use in evenings. We analyse costs, options, and whether batteries are worth adding to your system in 2026.
Battery Storage Costs
| Brand | Capacity | Typical Cost | Warranty |
|---|---|---|---|
| Tesla Powerwall | 13.5 kWh | £5,500-£6,500 | 10 years |
| GivEnergy All-In-One | 5.2-9.5 kWh | £2,500-£4,500 | 10 years |
| Growatt Hy10 | 10 kWh | £3,500-£4,200 | 10 years |
| SolaX Uni | 6.4-12.8 kWh | £3,000-£5,500 | 10 years |
| Pylontech US5000 | 15.36 kWh | £4,500-£5,500 | 10 years |
How Battery Storage Works with Solar
During the day, excess solar generation charges your battery. In evenings and nights, the battery powers your home instead of drawing from the grid. This increases self-consumption from 30% (without battery) to 70-80% (with battery).
Typical setup: 4kW solar system + 10 kWh battery. Solar generates 3,200 kWh/year. Battery stores 2,240 kWh for evening use. Remaining 960 kWh exported to grid.
1. Tesla Powerwall
Capacity: 13.5 kWh | Cost: £5,500-£6,500 | Warranty: 10 years
Premium option with best build quality, integrated monitoring, and proven reliability. Requires Tesla-compatible inverter. Best for customers wanting a premium, well-integrated system.
2. GivEnergy All-In-One
Capacity: 5.2-9.5 kWh | Cost: £2,500-£4,500 | Warranty: 10 years
Excellent value with integrated inverter. Works with most existing systems. Growing UK installer network. Good choice for budget-conscious customers.
3. Growatt HY10
Capacity: 10 kWh | Cost: £3,500-£4,200 | Warranty: 10 years
Reliable hybrid inverter/battery. Good efficiency, straightforward installation. Popular with UK installers. Excellent mid-range option.
4. SolaX Uni
Capacity: 6.4-12.8 kWh | Cost: £3,000-£5,500 | Warranty: 10 years
Scalable modular design. Can start small and expand. Good efficiency ratings. Growing UK support network.
Battery Size: How Much Do You Need?
3-6 kWh Battery: Covers evening peak usage (6-9pm). Good for light users, cost £2,500-£3,500.
10 kWh Battery: Covers full evening plus morning demand. Most common choice, cost £3,500-£5,000.
15+ kWh Battery: Provides 24+ hours autonomy. For off-grid or very high usage, cost £5,000-£7,000.
Is Battery Storage Worth It?
Annual Benefit Calculation:
Without battery: 30% self-consumption × 3,200 kWh = 960 kWh self-use × £0.245 = £235 savings
With 10kWh battery: 70% self-consumption × 3,200 kWh = 2,240 kWh self-use × £0.245 = £548 savings
Additional annual benefit: £313
Battery cost: £4,000
Payback period: 13 years
Verdict: Batteries don’t improve payback for most homeowners when buying new. Better to increase solar array size instead. However, batteries make sense if: (1) Adding to existing system, (2) Using time-of-use tariffs, (3) Wanting energy independence, (4) Have space for larger solar array already.
Installation Time & Complexity
Adding battery to existing solar: 1-2 days installation, £300-£600 labour. Requires inverter upgrade if very old system.
New system with battery: 2-3 days total, £5,000-£7,000 all-in for 4kW solar + battery.
Get Battery Quotes
Get free quotes for solar battery storage from MCS-certified installers in your area.