How Much Can You Save With a Solar Battery in the UK?
A solar battery doesn’t generate electricity. What it does is change how much of your solar generation you actually keep, which directly changes how much you save. For most UK households, that shift is worth £400–£700 per year on top of what your solar panels are already delivering.
Here’s a realistic breakdown of where those savings come from and what to expect from your own setup.
The Two Numbers That Drive Your Savings
Solar battery savings come down to two figures:
- Your electricity import rate – what you pay your supplier per kWh
- Your export rate (SEG) – what your supplier pays you for unused electricity sent back to the grid
Right now, the Ofgem energy price cap sits at 24.67p per kWh for electricity from April to June 2026. SEG export rates range from around 4p to 15p per kWh on fixed tariffs, with top time-of-use tariffs reaching 25-30p at peak hours for households with a battery. OfgemUK Solar Calculator
The gap between what you pay to buy and what you’re paid to sell is where the financial case for a battery lives. If you’re importing at 24.67p and exporting at 4-6p, every kWh you store and use yourself is worth around 20p more than the same kWh sent back to the grid.
How Much You’ll Actually Save
Without a battery, most UK households use 30-50% of the electricity their solar panels generate. The rest is exported. Adding a battery lifts self-consumption to around 80%, meaning a much larger share of your generation offsets your import bill rather than earning the lower export rate.
Here’s how that plays out for typical UK system sizes:
| System | Annual Generation | Solar-only Saving | Solar + Battery Saving | Extra from Battery |
| 4kW (10 panels) | ~3,800 kWh | £550–£750 | £1,000–£1,300 | £400–£550 |
| 5kW (12 panels) | ~4,700 kWh | £700–£900 | £1,250–£1,600 | £500–£700 |
| 6kW+ (14+ panels) | ~5,600 kWh | £850–£1,100 | £1,450–£1,900 | £600–£800 |
These figures assume an import rate of 24.67p/kWh, a flat SEG rate of around 6p, and typical UK household usage of 2,700 kWh per year. A higher SEG rate or a time-of-use tariff like Octopus Flux can push savings further.
What Increases Your Battery Savings
Three factors push your savings toward the upper end of the range:
Higher electricity prices. Every time the price cap goes up, your battery becomes more valuable, because you’re avoiding more expensive imports. The reverse is also true.
Time-of-use tariffs. Tariffs like Octopus Flux pay up to 29p/kWh during peak hours for households with a compatible battery. Charging your battery from cheap overnight rates and discharging during peak times can add a meaningful uplift.
High evening usage. Households that use most of their electricity in the evening benefit most. The battery stores solar generation during the day and releases it when grid prices are highest.
What Reduces Your Savings
A battery isn’t always the right move financially. A few things to be aware of:
- Low daytime occupancy. If nobody is home during the day, a battery still adds value, but you’re already exporting most of your generation anyway, which lowers the marginal benefit.
- Smaller solar systems. A 2kW system with a battery may not generate enough surplus to justify the upfront cost.
- Lower export rates. If you’re on a flat 4-6p SEG rate, the battery case strengthens. If you’re on a higher rate like 15p, exporting more isn’t as costly.
The Payback Picture
A typical home battery costs between £4,000 and £7,000 installed depending on capacity and brand. With annual savings of £400–£700 from the battery itself, most UK households see payback in 8-12 years.
That sits inside the warranty period for most modern lithium batteries, which typically run 10-12 years. After payback, every year of additional life delivers pure return on investment.
When a Solar Battery Makes Financial Sense
A solar battery is usually the right decision if you have:
- A solar PV system generating 4kW or more
- Higher than average evening electricity usage
- An import rate above 22p/kWh
- A flat-rate SEG tariff under 10p/kWh
If all four apply, you’re likely to land toward the higher end of the savings range. If only one or two apply, the financial case is still positive but the payback period stretches.
Get a Personalised Savings Estimate
Generic figures will only get you so far. Actual savings depend on your roof, your usage pattern, your tariff, and the battery you install. For a free site visit and a clear projection of what a solar battery will save for your property, call 01633 270 285 or request a quote.