In 2026 the cost of solar battery storage in the UK is typically £3,000 to £7,000 installed for a 5kWh to 10kWh battery, with larger 13.5kWh to 15kWh+ systems costing around £6,500 to £10,000 or more. Batteries fitted at the same time as new solar panels are usually cheaper than retrofits, and home battery installation is currently 0% VAT until 31 March 2027.
This guide breaks down solar battery costs by size, explains what a quote should include, and works through the savings and payback on a time-of-use tariff with the assumptions shown, so you can judge whether a battery is worth it for your home. It is written from the perspective of an MCS certified installer, so it also covers the practical things that push a price up or down on the day.
Solar battery storage prices in 2026 at a glance
The table below shows typical UK installed prices by battery capacity. The first column is the cost of adding a battery to an existing solar system. The second is the extra cost of the battery when it is installed at the same time as new solar panels, where scaffolding, the inverter and the electrical work are already being paid for.
| Usable capacity | Retrofit to existing solar | Added to a new solar install | Typical household |
|---|---|---|---|
| 5kWh | £3,000 to £4,600 | £2,500 to £4,000 | 1 to 2 people, low evening use, around 2,000 to 3,000kWh a year |
| 10kWh | £4,500 to £7,000 | £4,000 to £6,000 | Average family home, around 3,000 to 4,500kWh a year |
| 13.5kWh | £6,500 to £9,500 | £6,000 to £8,500 | Larger homes, EV owners, heat pumps |
| 15kWh and above | £7,000 to £10,000+ | £6,000 to £9,000+ | High usage, EV plus heat pump, or tariff optimisation |
These are market ranges drawn from UK price guides published in 2026, including the Energy Saving Trust, which puts a typical 5kWh battery system at around £4,600. Our own guide price for a battery added to a solar install is typically £3,000 to £6,000, depending on size and brand. Premium all-in-one units with whole-home backup sit at the top of each range; modular batteries from value brands sit at the bottom.
Solar panels and battery cost together
If you are buying everything at once, the combined solar panel price with a battery is typically:
- Around 3 to 4kWp of panels with a 5kWh battery: roughly £8,000 to £11,000 installed.
- Around 4 to 6kWp of panels with a 10kWh battery: roughly £10,000 to £14,000 installed.
- Larger 6 to 8kWp systems with 13kWh+ of storage: roughly £12,000 to £16,000+.
For reference, Octopus Energy quoted its most popular 12-panel system with a 10kWh battery at £11,115 on July 2026 prices. For a full breakdown of panel-only prices, see our solar panel cost guide for 2026.
What is included in a solar battery installation price
A like-for-like comparison between quotes is only possible if you know what each one includes. A proper home battery installation quote should cover:
- The battery itself: almost always lithium iron phosphate chemistry in 2026, with the usable capacity stated, not just the headline figure.
- An inverter: either a hybrid inverter that runs both panels and battery, or a battery with its own built-in inverter.
- Installation labour: typically a half day to a full day for a retrofit, and part of a one to two day job alongside new panels.
- Electrical work: cabling, isolators, protection devices, a CT clamp or energy meter, and sometimes a consumer unit upgrade.
- Backup power, if wanted: an emergency power supply circuit or a whole-home gateway so the battery keeps running during a power cut.
- Commissioning and set-up: connecting the monitoring app, setting charge schedules for your tariff and testing the system.
- Paperwork: notifying your network operator, Part P building regulations certification, and MCS certification where applicable.
Hardware is the biggest single cost, but it is not the whole story. Bare battery modules from online retailers start at under £1,000 for around 5kWh, which is why some headline prices look very low. Those prices exclude the inverter, installation, commissioning and warranty support, and supply-only batteries do not qualify for the 0% VAT rate.
Hybrid inverter or AC-coupled battery?
This is the single biggest variable in a retrofit price.
- You already have a hybrid inverter: the battery connects straight to it. This is the cheapest retrofit, often only the battery plus a few hundred pounds of labour.
- You have a standard string inverter: you can either fit an AC-coupled battery with its own inverter, leaving your panels untouched, or replace the old inverter with a hybrid unit. Either route typically adds around £1,000 to £2,000.
- Your inverter is old or near the end of its life: replacing it with a hybrid inverter at the same time often makes sense, as you would be paying for a new inverter within a few years anyway.
Retrofit vs installing a battery with new solar
Installing a battery at the same time as new solar panels is usually £500 to £1,500 cheaper than adding one later. That is because one hybrid inverter does both jobs, the electrician is already on site, and the design, network notification and certification are done once.
A retrofit costs more but can still be a sound decision. It lets you see your real generation and usage data before choosing a battery size, and most solar systems can take a battery. If you are unsure, a sensible middle route when buying panels now is to specify a battery-ready hybrid inverter, which typically costs a few hundred pounds more than a standard inverter and saves a second inverter swap later. Our UK solar battery guide compares the main brands and the retrofit process in more detail.
New-build homes are a slightly different case. If a developer is fitting solar panels anyway, adding a battery during the build is usually the cheapest time of all, although not every developer offers it as an upgrade.
VAT on solar batteries in 2026
Home batteries currently attract 0% VAT. According to HMRC’s VAT Notice 708/6, the zero rate applies from 1 February 2024 to 31 March 2027 to batteries installed in residential accommodation, including:
- batteries installed with new solar panels,
- batteries retrofitted to an existing solar system, and
- standalone batteries that charge from the grid.
From 1 April 2027 the rate is due to return to the reduced rate of 5%, not the full 20%. On a £5,000 battery that would add around £250. The relief only applies when the battery is supplied and installed; buying a battery supply-only is standard-rated at 20%. If you are planning a battery, getting it installed before the end of March 2027 locks in the saving. Our guide to 0% VAT on solar panels explains how the relief works in practice.
Running and replacement costs
Day-to-day running costs
A home battery has very low running costs. There is no fuel and no routine servicing in the way a boiler needs. The ongoing costs to be aware of are:
- Round-trip losses: a modern battery returns roughly 90% of the energy put in, so about 1kWh in every 10 is lost.
- Standby consumption: the battery and inverter use a small amount of power to stay on.
- Optional health checks: some owners pay for an inspection every year or two; it is not normally a warranty condition, but check your manufacturer’s terms.
Lifespan and replacement
Most home batteries carry a 10-year warranty and are expected to last around 10 to 15 years. They fade gradually rather than stopping suddenly. Warranties usually guarantee around 60 to 80% of original capacity at the end of the term, so a 10kWh battery might be holding 7 to 8kWh after a decade.
Budget for two things over the long term:
- Inverter replacement: hybrid inverters often need replacing after 10 to 15 years, typically costing around £1,200 to £2,500 installed at today’s prices.
- Battery replacement: at today’s prices a replacement battery would cost broadly what the original did, but battery prices per kWh have fallen steadily and are expected to be lower when replacements are due.
How much can a battery save? A worked example
Savings depend far more on your tariff and habits than on the battery. Here is a worked example for a typical family home, with every assumption stated so you can adjust it for your own situation.
Assumptions
- A 10kWh battery, cycling around 8kWh a day into the home, with 90% round-trip efficiency.
- Existing solar panels of around 4kWp.
- A time-of-use tariff with an off-peak rate of 8.5p/kWh overnight and a day rate of 28p/kWh. Octopus Go, for example, advertised an off-peak rate of around 8.5p/kWh in September 2026. For comparison, the Ofgem price cap unit rate for October to December 2026 is 26.32p/kWh.
- An export rate of 12p/kWh for surplus solar.
Winter, October to March
Solar surplus is small, so the battery charges overnight from the grid. Charging 8.9kWh at 8.5p costs about 76p. Using 8kWh from the battery instead of buying it at 28p avoids £2.24. That is a saving of about £1.48 a day, or around £270 over 182 days.
Summer, April to September
The battery fills with surplus solar that would otherwise be exported. Say 7kWh a day goes in and 6.3kWh comes out. You give up 84p of export income but avoid £1.76 of peak-rate imports, a saving of about 92p a day, or around £170 over 183 days.
Total and payback
| Scenario | Estimated annual saving | Battery cost | Simple payback |
|---|---|---|---|
| Retrofit, time-of-use tariff, 12p export | Around £440 | £5,000 | Around 11 years |
| With new solar, time-of-use tariff, 12p export | Around £440 | £4,000 | Around 9 years |
| With new solar, time-of-use tariff, 4p basic export rate | Around £540 | £4,000 | Around 7 to 8 years |
| Flat-rate tariff, no overnight charging, 12p export | Around £170 to £200 | £5,000 | 25 years or more |
The pattern is clear. A battery earns its keep on a time-of-use tariff, because it can be charged cheaply every night of the year. On a flat-rate tariff it only saves the gap between the export rate and the import rate on stored solar, which is much less. A lower export rate actually makes a battery more valuable, because each kWh you store rather than export is worth more. Our guide to the Smart Export Guarantee in 2026 compares current export rates.
This example is simplified. It ignores gradual battery degradation, future price changes and the extra value some owners get from export tariffs that pay more at peak times. Treat it as a guide to the order of magnitude, not a guarantee.
Is a solar battery worth it?
A battery is most likely to be worth it if you:
- already have solar panels, or are installing them, and export a lot of surplus in the daytime,
- use most of your electricity in the evening, when nobody is home during the day,
- are willing to switch to a time-of-use tariff,
- have or plan an electric car or heat pump, which raises your overall usage, or
- want backup power during outages.
It is less likely to pay back if you are at home using most of your solar during the day anyway, have a small system with little surplus, want to stay on a flat-rate tariff, or plan to move house within a few years. If you have an EV, our guide to solar EV charging covers how a battery and car charger work together.
What size battery do you need?
The right size is the one that covers your evening and overnight use without leaving expensive capacity idle. A simple rule of thumb:
- Look at your annual usage on your bill and divide by 365 for a daily figure.
- Estimate how much of that is used after the sun goes down and before your cheap-rate window starts. For most homes it is roughly half to two thirds.
- Choose a battery with usable capacity close to that figure.
A home using 3,500kWh a year uses about 9.6kWh a day, of which perhaps 6 to 7kWh is in the evening. A 10kWh battery suits that home well. A 5kWh battery would suit a smaller household, while a home with a heat pump or EV may justify 13.5kWh or more. Bigger is not automatically better; an oversized battery that never fills or empties fully adds cost without adding savings.
kW vs kWh: what a 10kW battery means
Many people search for a 10kW battery when they mean 10kWh of storage. kWh is the amount of energy stored. kW is the power, meaning how fast the battery can charge or discharge. Most home batteries deliver 3 to 6kW, enough for normal household use but possibly not for an electric shower, oven and kettle all at once. Check both figures on any quote.
Does a battery without solar make sense?
Yes, in the right circumstances. A standalone battery charges from the grid overnight on a cheap rate and runs your home during the day and evening. Using the same assumptions as the worked example, a 10kWh standalone battery cycling 8kWh a day could save roughly £400 to £540 a year, similar to a battery paired with solar on a time-of-use tariff. Standalone batteries also qualify for 0% VAT until 31 March 2027.
The risks are that it relies entirely on the gap between peak and off-peak prices staying wide, and on you staying on a suitable tariff. With solar, the battery also stores free energy, which gives you a second source of value if tariffs change. For most homeowners with a suitable roof, adding panels as well gives the stronger long-term case.
What affects the price of your quote
- Capacity and brand: the largest factor. Premium integrated systems cost more per kWh than modular stacks.
- Inverter compatibility: whether your current inverter can run a battery.
- Location: the British Standard PAS 63100:2024 rules out lofts, bedrooms and escape routes such as hallways and landings. A garage, utility room or suitable outside wall is typical. Longer cable runs cost more.
- Backup power: whole-home backup gateways add cost compared with a single emergency socket or none.
- Network approval: systems rated above 3.68kW per phase on a single-phase supply normally need G99 approval from your network operator before switch-on, which can take several weeks.
- Consumer unit condition: older fuse boards may need upgrading.
How to get a fair price
- Get at least two or three quotes that state usable capacity, the inverter model, backup options and warranty terms.
- Use an installer certified by the Microgeneration Certification Scheme and registered with an electrical competent person scheme such as NICEIC.
- Ask for a savings estimate based on your actual usage and your intended tariff, not national averages.
- Check who handles the network notification and building regulations sign-off.
- Be wary of quotes that look far cheaper than the ranges above; they often exclude the inverter, electrical work or VAT-compliant installation.
Frequently asked questions
How much does it cost to add battery storage to a solar system?
Adding a battery to an existing solar system typically costs around £3,000 to £7,000 installed in 2026. A 5kWh battery is usually at the lower end and a 10kWh battery at the upper end. If your current inverter cannot run a battery, either an AC-coupled battery or a new hybrid inverter is needed, which can add roughly £1,000 to £2,000.
How much does a 10kWh solar battery cost in the UK?
A 10kWh battery typically costs around £4,000 to £6,000 when fitted alongside new solar panels, and around £4,500 to £7,000 when retrofitted to an existing system. Brand, backup power features and how much electrical work is needed all move the price.
How long will a 10kWh battery last?
On a single charge, a 10kWh battery with around 9 to 9.5kWh usable capacity will run a typical home’s evening and overnight use of 6 to 9kWh, so most households get through to the next cheap-rate period or the next morning’s solar. Over its life, most home batteries carry a 10-year warranty and are expected to last around 10 to 15 years.
Is it worth getting battery storage with solar panels?
Usually yes, if you pair it with a time-of-use tariff and use most of your electricity in the evening. In our worked example a 10kWh battery saves around £440 to £540 a year, giving a payback of roughly 7 to 11 years. On a standard flat-rate tariff with a good export rate, savings are much smaller and payback can run past 20 years.
Is there VAT on solar batteries in 2026?
No. Batteries installed in homes are zero-rated for VAT until 31 March 2027, whether fitted with new solar, retrofitted to existing panels or installed on their own. From 1 April 2027 the rate is due to return to 5%. Buying a battery supply-only, without installation, is charged at the standard 20% rate.
Can you get a home battery without solar panels?
Yes. A standalone battery charges from the grid at a cheap overnight rate and powers your home at peak times. It works best on a tariff with a large gap between off-peak and peak prices, and it also qualifies for 0% VAT until 31 March 2027 when installed in a home.
How often does a solar battery need replacing?
Most lithium iron phosphate home batteries are warrantied for around 10 years and are expected to last 10 to 15 years. They lose capacity gradually rather than failing suddenly, and many warranties guarantee around 60 to 80% of original capacity at the end of the term. Hybrid inverters often need replacing sooner, typically after 10 to 15 years.
What is the difference between a 10kW and a 10kWh battery?
kWh measures how much energy a battery stores, while kW measures how fast it can charge or discharge. A 10kWh battery stores 10 units of electricity. Its power rating, often 3 to 6kW for home systems, decides how many appliances it can run at once. When people search for a 10kW battery they almost always mean 10kWh of storage.
Are there grants for solar batteries?
There is no universal grant for home batteries in 2026. The main saving for most households is 0% VAT until 31 March 2027. Some lower-income households may be eligible for government-funded schemes such as the Warm Homes: Local Grant, which is run by local councils and has its own eligibility rules.
Get an accurate battery price for your home
The ranges above give you a realistic budget, but the right battery depends on your roof, your inverter, your usage and your tariff. Greener Solar Solutions is an MCS certified, NICEIC approved installer with directly employed electricians, covering Sussex and Surrey. We check inverter compatibility, suitable battery locations and your usage data, then give you a fixed price and an honest savings estimate. Find out more about our battery storage installations, or book a free survey to get a quote.
