How much do solar batteries cost?

A solar battery is one of the best ways to get the most out of your solar panel system – but before you do, you’ll want to see how much it costs and saves you.

After all, you only want to buy an extra piece of solar gear for your home if it can help you cut your electricity bills even further.

In this guide, we’ll explain how much different sizes of solar battery cost, which factors affect the price, and whether a solar battery is worth the investment.

If you’re wondering how much a solar & battery system could save you, just answer a few quick questions below and we'll generate an estimate.

What’s the average cost of a solar battery?

The average cost of a 5kWh solar battery is roughly £5,000, including the price of installation and an inverter – but this figure varies, depending on the battery’s size and whether it’s part of a wider system installation.

For instance, if you add a 5kWh battery onto a solar panel system installation, its price generally falls to between £2,000 and £3,000, as you’re already paying for the labour and an inverter.

And a 10kWh battery costs around £7,000 by itself, on average – but if it’s part of a solar & battery project, its price typically drops to £4,000-£5,000.

As usual, you’re better off making all your planned changes to your home at once – otherwise you’ll end up paying more than you need to.

Do you have to pay VAT on solar batteries?

You don’t have to pay any VAT on solar batteries.

In February 2024, the government added standalone solar batteries to its list of energy-saving materials that qualify for a 0% VAT rate until 2027.

Before that point, you had to pay 5% VAT to purchase a solar battery on its own.

As well as solar panels and batteries, you also don’t have to pay VAT on renewable systems including air and ground source heat pumps, water turbines, micro combined heat and power units, and wind turbines.

What factors affect the cost of a solar battery?

Multiple factors affect the cost of a solar battery.

You’ll usually pay a higher price for a more technologically advanced battery, and a bigger battery also typically costs more than a smaller model.

If you choose certain manufacturers or installers over others, you can also save money – or potentially pay more for a better result.

Here are the key factors, followed by more detail about each of them:

Battery size

The bigger the battery, the higher its price, as a rule.

For instance, you’ll pay around £2,000 more to buy a 10kWh battery than a 5kWh version.

It’s therefore worth taking the time to assess your solar generation and electricity consumption, to make sure your battery fits your needs.

Battery quality

As with most products, the quality of your solar battery will go a long way to determining its price.

Make sure you check your battery’s depth of discharge (DoD), as this will tell you how much of its kWh size you’re able to use without degrading the battery in the long run. This may also be referred to as its ‘usable capacity’.

A battery with 100% DoD, meaning you’re able to use its entire capacity, will usually be worth more than a model with 80% DoD, all other things being equal.

The battery’s rate of discharge also affects its price. If it’s high, you’ll be able to use smart battery controls and the best export tariffs more effectively, which should help you to save more on your electricity bills, but will likely cost more upfront.

Consider a battery’s efficiency rate as well, as this shows how much electricity is retained during the transfer from your panels to your battery.

Lithium-ion batteries are usually around 96% efficient, so a higher rate will likely result in a steeper price.

Look through a battery’s datasheet to find these statistics, or ask an installer.

Whether it’s installed with solar panels

The price of installing a solar battery falls by around £2,000-£3,000 if it’s installed at the same time as solar panels.

The price of the inverter is already folded into the total amount of a solar panel system installation, and adding a battery doesn’t involve much additional labour cost either.

This is why it’s also better to add all your solar panels to your system at once, rather than leaving some for later to try to spread out the cost – as it’ll have the opposite effect.

The battery’s manufacturer and installer

A battery’s price can be affected by the brand name it’s attached to, with some companies charging more to position themselves as prestigious, or because they’re genuinely more trusted or highly regarded than others.

The manufacturer’s policies may also affect the price of a battery. A longer warranty may make your purchase more expensive, for instance – though a shorter one may lead to higher overall costs in the long run.

And the way your installer prices their services will impact the cost too, depending on factors including your location, the complexity of the project, and how many engineers are required.

What’s the cheapest type of solar battery?

The cheapest type of solar battery that’s widely available is the lead-acid battery.

These batteries, which you can see in most cars, typically last three to seven years – or less, if you don’t keep up with their numerous maintenance needs.

Lithium-ion batteries are usually more expensive but have a higher average lifespan, at 10-12 years, and very few maintenance needs.

It’s worth choosing a high-quality lithium-ion battery if you want to make the most of your investment in a solar panel system to save the most money and carbon emissions.

Ultimately, it’s no good generating enough electricity to save hundreds of pounds and a tonne of CO2 per year if your battery isn’t able to hold onto the energy effectively – and if you need to replace it every few years.

With a more upmarket model, you can use smart battery controls to make the most of your smart export tariff and save the most money possible each year.

If you would like to see the savings you could get from a solar & battery system, answer a few quick questions below and we’ll provide an estimate.

Are solar batteries worth the cost?

Solar batteries are absolutely worth the cost.

They can help you to combat the main issue with solar panels – that they can’t generate electricity at night – by storing electricity for as long as five days. 

This will enable you to use more of the electricity that your panels produce, which will cut your bills even further.

A solar battery also allows you to access smart export tariffs like Intelligent Octopus Flux and Octopus Flux, which can help increase your savings substantially.

And if you add a battery onto your initial solar panel system installation, it usually won’t cost that much extra – making it excellent value for money.

• You can save much more on your electricity bills with a battery
• A battery costs significantly less if it’s installed at the same time as your solar panels
• You can gain access to the best export tariffs on the market
• It can run your home in a power cut with Emergency Power Supply (EPS), if your installer has enabled it
• Using more of your solar electricity will lessen the impact of energy price rises
• A battery can help you to reduce your carbon footprint

Are there any grants available for solar batteries?

There are multiple grants and schemes that can help you get money off your solar batteries – though they’re all specific in a way that excludes most people.

Homeowners in Scotland can apply to the government’s Home Energy Scotland Grant and Loan scheme for grants and loans to fund renewable energy installations, including solar & battery systems.

You could potentially get a £1,250 grant and £4,750 interest-free loan for solar panels, and an identical package for a battery – equating to £12,000 overall.

If you live in social housing in England, you may be able to access measures including solar & battery systems through the Social Housing Decarbonisation Fund.

This government scheme has handed out millions of pounds to 107 local authorities and organisations – so if your council was successful, ask your representatives to help you out.

The government’s Home Upgrade Grant also provides millions of pounds of funding to local authorities in England, so they can pay for domestic measures including solar & battery systems.

If your home isn’t connected to the gas grid and has an Energy Performance Certificate (EPC) of D, E, F, or G, you may qualify for a free or largely discounted solar & battery installation.

You could also look into solar panel loans.

Solar battery maintenance costs

Lithium-ion solar batteries don’t need much maintenance, as long as you follow the manufacturer’s instructions when using them.

This may include limiting the maximum number of daily cycles, and not running them down below their stated depth of discharge. Ignoring either of these requirements will degrade your battery faster, meaning you’ll have to replace it sooner.

So if you’d like to help your battery’s health and potentially extend its lifespan, you could get an engineer to come round once per year to tell you how well you’re taking care of your battery.

This will cost around £100, with the actual price depending largely on your location.

Batteries don’t usually break down irretrievably, but with a lifespan of 10-12 years, they’re not a particularly long-term investment anyway – unlike solar panels, which last around 30-40 years.

That’s why Sunsave Plus is such an excellent choice: we'll provide you with a free out-of-warranty replacement battery.

Next steps

You now have all the information you need about how much solar batteries cost – and how to maximise their savings potential – to decide whether a battery is right for your home.

You can save thousands of pounds by installing them at the same time as your solar panels, and in return, they can help cut your electricity bills by hundreds of pounds per year.

However, they’ll likely only serve you properly for 10-12 years, after which point you’ll need to spend thousands of pounds on a replacement battery – unless you’re signed up to Sunsave Plus.

If you’re wondering how much a solar & battery system could save you, just answer a few quick questions below and we’ll provide you with an estimate.

Solar battery costs: FAQs