A home storage battery costs between £1,500 and £10,000 in the UK, and a typical 5kWh unit comes in around £4,600, per the Energy Saving Trust. Fitted alongside solar panels, a battery lets you use your own generation in the evening instead of selling it cheap and buying it back dear: exported units earn you around 12p each on a typical Smart Export Guarantee tariff, while every unit you avoid importing saves you 26.11p at the current price cap. That gap is the whole case for a battery. Whether it pays depends on the battery price, how much of your generation you currently waste, and the fact that the battery will need replacing years before your panels do.
How much does a solar battery cost in the UK?
The Energy Saving Trust puts home battery storage at £1,500 to £10,000 depending on type and size, with a 5kWh system costing around £4,600. A complete battery storage setup for a typical home sits in the £5,000 to £8,000 range. Capacity is the main price driver: a small 3 to 5kWh unit suits a modest solar array and low evening use, while bigger homes running heat pumps or car chargers push towards 10kWh and beyond. Source: Energy Saving Trust, battery storage.
Two ways to keep the price down:
- Install the battery at the same time as the panels. The installers are already on site, the scaffolding is already up, and the battery is integrated as part of one job. EST notes this is normally cheaper than coming back to retrofit later.
- Do not oversize it. A battery you never fill is capital doing nothing. Sizing follows your actual usage, not the biggest unit on the price list, and a good installer will work from your consumption figures. Our guide to choosing an MCS-certified installer covers the questions to ask.
For the panels themselves, budget around £6,100 for a typical 4.5kWp system before you add storage. The full breakdown is in our solar panel costs guide.
You pay 0% VAT on a battery until 31 March 2027
Battery storage is zero-rated for VAT across the UK until 31 March 2027, whether it is installed with your panels, retrofitted to an existing solar system, or even fitted on its own to charge from the grid. Batteries were added to the energy-saving materials relief on 1 February 2024, and HMRC's guidance names all three cases explicitly. From 1 April 2027 the rate reverts to the reduced rate of 5%, not the standard 20%. Source: gov.uk, VAT Notice 708/6.
The practical point: on a £4,600 battery, the zero rate is currently saving you a few hundred pounds against the post-2027 position, and over a thousand pounds against standard-rate VAT. The relief applies to supply-and-install jobs by a VAT-registered installer, which is how home batteries are normally bought. Buying a battery from a retailer without installation is standard-rated, so a supply-and-install quote is usually the better structure as well as the safer one.
How a battery changes the solar maths
Without a battery, the units your panels generate while the house is empty go to the grid for around 12p each. With one, those units come back out in the evening and replace electricity you would have bought at 26.11p. The 12p is the Energy Saving Trust's typical Smart Export Guarantee rate; the 26.11p per kWh is the electricity unit rate under the Ofgem price cap for 1 July to 30 September 2026 (direct debit average). So every unit a battery shifts from export to self-use is worth roughly 14p more to you than selling it.
Three things follow from that arithmetic:
- The saving scales with waste. If you are home all day and already use most of your generation, there is little left for a battery to shift, and the case weakens. Households out at work on weekdays, exporting half their generation, gain the most.
- Storage is not free energy. Some electricity is lost charging and discharging the battery, so a stored unit is worth slightly less than a directly used one. EST flags this round-trip loss as one of the trade-offs.
- The battery dies before the panels. Typical battery lifespan is 10 to 12 years against 25 or more for panels, so a full-life calculation has to include a replacement battery. Ask the installer about the warranty and expected cycle life in writing.
A battery also opens up smart time-of-use tariffs: charging cheaply overnight and discharging at peak, which works even on days the sun does not. That flexibility, rather than solar alone, is where much of a battery's value now sits. For the payback picture on panels themselves, see whether solar panels are worth it in the UK.
Do you still get SEG payments with a battery?
Yes. When your battery is full and your panels are still generating more than the house is using, the surplus exports to the grid and your SEG tariff pays out as normal, it just happens less often. The Energy Saving Trust makes exactly this point: a battery changes how often you export, not whether you can. SEG payments are calculated on export meter readings, rates are set by each supplier rather than government, and the scheme covers Great Britain only. As at mid-July 2026 tariffs ranged from about 3p to 18p per kWh, with the headline rates carrying conditions. Sources: Ofgem, Smart Export Guarantee; Energy Saving Trust.
You will need an MCS-certified installation to register for a SEG tariff, and it is worth comparing export rates before you pick a supplier, because the spread between the best and worst is wide. Current rates and their small print are in our Smart Export Guarantee comparison.
Is there a battery grant?
There is no universal battery grant, the same as there is no universal solar grant. The one scheme moving in that direction is the Warm Homes Plan: for low-income households it includes fully funded installations of solar panels and a battery, delivered in phases through social landlords and local councils, with wider eligibility detail due later in 2026. For everyone else the support is the 0% VAT rate above. The full picture, scheme by scheme, is in our guide to solar panel grants in the UK.
The practical details worth knowing
A typical home battery is about 100cm by 60cm by 25cm, roughly a slim washing machine, and usually lives in a garage, utility room or on an external wall. A few more practicalities from the Energy Saving Trust and the Energy Networks Association:
- Grid paperwork. Solar installations up to 3.68kW per phase connect under the simple G98 notify-after process. Adding a battery can take the combined inverter capacity of a solar-plus-battery system above that threshold, which means the installer applies to your network operator for G99 approval before connecting. Your installer normally handles either route; it mainly affects timing, so ask which applies to your quote. Source: Energy Networks Association.
- The system protects itself. Batteries stop discharging at a set floor, around 20% of capacity, because running to empty shortens their life. Usable capacity is therefore a little less than the headline figure, another question worth putting to the installer.
- Use an MCS-certified installer and get at least three quotes. EST's advice for batteries matches its advice for panels, and it keeps your SEG registration straightforward.