- A solar storage battery for a typical house costs around £5,000
- You can save money on a battery by having it installed at the same time as solar panels
- A ‘solar plus storage’ system cuts the average home’s annual energy bill by nearly £600
A solar storage battery is well worth having in the UK. If you add a battery to your solar panel system, you can use much more of the electricity your panels produce.
This is because a battery stores any excess energy your solar panels produce when the sun shines, so you can use it to power your home after dark. Your energy bills and fossil fuel usage fall much further than if you have solar panels alone.
The best solar storage batteries also let you store electricity from other sources, such as from the grid during off-peak hours.
But while a battery can save you a fortune in electric bills, it is a chunky upfront investment. The average price of a storage battery for a UK home is £5,000.
Prices vary according to factors including a battery’s capacity, lifespan and brand name. You can also cut the cost of solar panels and a battery by having them installed at the same time. We’ll go into detail about battery costs and savings below.
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How much does a solar storage battery cost in 2025?
You can buy a solar storage battery for less than £2,000 or more than £11,000. But if you’re looking for a battery with a medium capacity of 5 kWh (kilowatt hours), which is ideal for a three-bedroom house, expect to pay around £5,000.
Capacity is the main factor that dictates how much a storage battery costs. It works out at around £900-£1,000 per kWh of electricity a battery can store.
The more solar panels you have, and the higher your energy usage, the larger your battery’s capacity will need to be.
Many of the best batteries are modular or stackable, which means you can add extra units to increase the system’s overall capacity. This lets you start small, then scale your storage system as your solar output or energy needs grow.
What size solar battery do I need?
The size (capacity) of solar storage battery you need depends on how much electricity you produce and use.
A large capacity battery is ideal for you if have a big solar PV system that generates 8 kWp or more per day, most of which you use in the evening. The battery will bank all that energy and let you use it 24/7.
If your household and PV system are small, your battery capacity needs will be small too.
Don’t be tempted to buy a bigger battery than you need. If a battery can’t fully empty and recharge (fill back up) regularly, it won’t perform as well as it should.
Note that a battery’s headline capacity is not always the same as its “usable capacity”. This refers to the amount of stored energy you can actually use, minus the small amount (usually 5-10%) used by the battery while charging and discharging.
The table below gives you a rough idea of battery prices, including professional installation. Make sure to get at least three quotes when shopping around.
| House size | Solar system size | Size battery needed | Average battery price |
|---|---|---|---|
| 1-2 bedrooms | 2.1 kWp (6 panels) | 4 kWh | £4,000 |
| 3 bedrooms | 3.5 kWp (10 panels) | 5 kWh | £5,000 |
| 4+ bedrooms | 4.9 kWp (14 panels) | 10 kWh | £9,000 |
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Get startedWhat makes one storage battery cost more than another?
Size isn’t everything. The price of a solar storage battery is affected by many factors other than capacity. Brand name, for example – as you’ll know if your eyes have watered over the price of Tesla batteries. Here’s what else comes into play:
Battery type
There are two main types of battery: lithium-ion and lead-acid.
Most storage batteries are lithium-ion. They are slightly more expensive to buy than lead-acid batteries, but they’re better performers and have a longer lifespan.
Lead-acid batteries have a cheaper upfront cost but don’t perform as well, especially as the years pass. They may end up costing you more in the long run because they’re more likely to need replacing.
Here’s a quick comparison:
| Features | Lead-acid battery | Lithium-ion battery |
|---|---|---|
| Capacity | 4 kWh (example) | 4 kWh (example) |
| Average price | £2,000 | £4,000 |
| Average depth of discharge | 50% | 90% |
| Average cycles | 1,800 | 4,000 |
| Cost per kWh, per cycle | 56p | 28p |
Lifespan (cycles)
The table above mentions the number of “cycles” a 4 kWh lithium-ion and lead-acid battery will achieve in its lifetime, on average. One cycle means one full charge and discharge of the battery.
More cycles generally means a longer lifespan. The more times a battery can empty and recharge, the healthier it is and the more years you can expect it to last.
Batteries with more guaranteed cycles tend to cost more than batteries with fewer cycles, but it’s not an exact science. One of our 7 best storage batteries, the Alpha Smile5 ESS 10.1, boasts 10,000 expected cycles (much higher than average) but offers superb value for money at around £4,000 for a usable capacity of 9.1 kWh.
Depth of discharge (DoD)
This refers to the amount of electricity you can extract from a battery before it needs recharging. It’s similar to usable capacity, but not quite the same.
It’s rare for a solar storage battery to have a DoD of 100%. Most batteries can be drained about 90% before they need recharging.
This is a common principle with rechargeable batteries, including the ones in your phone and laptop.
That said, a few of the best solar storage batteries do have a DoD of 100%. Examples include the new Enphase IQ Battery 5P, which can be completely drained of its 5 kWh capacity before it needs recharging.
Warranty
Solar batteries typically come with a 10-year warranty.
That’s less than half the typical 25-year warranty period for a solar PV system, so be aware that you may need to replace your storage battery long before you replace your panels.
Occasionally a battery will come with a longer warranty – and that doesn’t always make it especially expensive. The Moixa Smart Battery, another of our 7 best storage batteries, costs a good-value £4,500 for a 4.8 kWh model and comes with an unlimited warranty if you join Moixa’s Gridshare Cashback Scheme.
Scalability
Stackable and modular battery systems let you scale your battery capacity as needed. This means you can start with a smaller battery and add more units later.
The modular option normally adds a bit to the price of a battery, but not always. The stackable Huawei Luna 2000-10 is excellent value, costing around £3,500 per 5 kWh unit. You can connect as many as six units to create a whopping total capacity of 30 kWh.
Smart features
The more expensive solar batteries normally include “smart charge” functions, which mean they automatically calculate their charging patterns according to factors such as your energy usage.
You can manage your battery’s smart functions and track various metrics via a mobile app.
Many premium batteries also offer automatic power cut support. They instantly provide you with emergency power without feeding any current back into the grid – to spare the safety of any poor engineers working to restore power.
Installation cost
Solar storage batteries must be installed by qualified professionals, so that’s another cost to take into account. Large, premium batteries may cost more to install than smaller, cheaper ones.
Installation costs also vary based on based on the size of battery you need, your location and the layout of your property. You can normally knock a bit of money off if you’re having solar panels installed at the same time.
Solar battery cost calculator
The bigger your house and the more energy you use, the higher capacity your solar battery will need – and the more you’ll need to pay for it.
Here’s a quick cost calculator to help you plan:
Is a solar storage battery worth buying?
A storage battery cuts your energy bills, shrinks your carbon footprint and can even keep your home running in a power cut. But it costs thousands to buy and install, and may not break even for decades – if ever.
The pros, cons and costs aren’t the same for everyone. Here’s a quick summary:
Long term benefits
- A solar battery system helps to protect you from energy price rises, since it means nearly all your electricity will come from solar.
- A three-bedroom property with a solar panel system and a 5kWh battery will save nearly £600 per year through reduced electricity bills.
- A solar battery is one of the best ways to reduce your carbon footprint. Over the lifetime of your solar panels, a battery can prevent an additional 28 tonnes of greenhouse gas emissions from entering the atmosphere.
- Many batteries can automatically keep your home powered during a power cut. If you work from home, it could protect your livelihood!
Short term costs
- The average solar panel system costs more than £7,000, so £5,000 on top of that for a battery is a huge chunk of money to find.
- It takes longer to break even on a solar-plus-battery system than on solar panels alone: around 26 years compared to 15.66 years without a battery.
- The additional savings on your bills from adding a battery are unlikely to outweigh the cost of the battery, since batteries only last 10-15 years.
- A storage battery takes up roughly the same amount of space as a washing machine or combi gas boiler.
- If you already have solar panels, you may have to buy an additional inverter if you want an AC (alternating current) battery. An inverter typically costs £800.
- There’s arguably little point in buying a storage battery if you have an EV (electric vehicle). Instead of storing the excess energy from your panels, you could just use it to charge your car.
Find more info about the costs and benefits of batteries in our article asking whether solar batteries are worth buying in the UK.
How big is your solar panel system, and how roughly much did it cost?
“We had a combined package of solar panels and solar batteries, with a capacity of 13.8 kilowatts (kW). The total cost was £14,500. The panels were about £5,000.”
Do your solar panels generate enough power to cover all your electricity needs?
“In June, which was sunny, we used solar for almost all our electricity needs, including the car and hot water. In July and August, we had to use some grid power overnight to charge the batteries because the weather wasn’t so good.”
Have you managed to break even on your solar panels?
“We won’t break even for a few years yet, but feel we have pre-bought our energy and are protected from the vagaries of the energy market.”
Kassy lives in North Yorkshire, and has owned solar panels and solar batteries since February 2023.
Which solar products are you interested in?
Get startedNext steps
By now, you’ve made up your mind whether or not to include a solar battery with your solar PV system.
If you don’t already have panels, the next step is to compare quotes for panels alone or panels with a battery.
Pop a few details into this free form, and we’ll ask a hand-picked selection of installers to get in touch with a tailored quote.
Frequently asked questions
What happens when batteries fill up?
Once your solar battery is full, it will stop storing electricity from your solar panels. The excess electricity that your panels produce will just go to the national grid.
If your battery is connected to the grid and you’re part of the government’s Smart Export Guarantee (SEG), you’ll earn money from the excess you export.
Should I get a bigger battery than I need just in case?
No. If your battery’s capacity is bigger than your energy needs and bigger than your solar PV system’s output, it will struggle to complete full cycles properly and it won’t work to the best of its ability.
If you’re worried about needing extra energy storage at some point, get a stackable battery whose capacity you can increase as your needs grow.
How many hours will a solar battery last?
If your electricity is cut off, a fully-charged 10 kWh battery can power your house for around 30 hours. It’ll power you for less time if you use more electricity, for example if you do multiple loads of laundry in a day – or you work from home and you’ve forever got the kettle on. Maybe not the best strategy in a power cut!
