A standalone battery allows you to buy and store cheap, off-peak electricity, then use it throughout the day to replace more expensive grid electricity.

This process can cut your energy bills by hundreds of pounds per year – and you can secure additional savings by joining a virtual power plant.

In this article, we’ll explain how it works to have a standalone battery, how much it costs, and which households should consider making this step.

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

How does a battery-only system work?

As with solar panels, you’ll need a professional installer to set up your system.

However, you'll need to sign up for a time-of-use tariff yourself - an installer can't do this for you.

Here’s more detail about these steps.

Installation

Your installer will first work out where to put your battery, which will ideally be outside or in your garage (as per the latest guidelines).

They’ll then install an inverter one or two metres away from your battery, if it’s not built-in.

The inverter will convert the grid’s Alternating Current (AC) electricity into Direct Current (DC) electricity that you can store in your battery.

It’ll then convert this DC power back into AC electricity that you can use in your home. The speed of this conversion process depends on the size of the inverter.

Your inverter will also send information to the grid and your app, which is made by the inverter’s manufacturer, so that everyone involved always knows what’s happening.

Your battery will probably be AC-coupled, meaning it’ll be an all-in-one machine, with both battery and inverter capabilities.

Your installer will also run a communication cable, usually known as a comms cable, between the battery and your supply meter.

Time-of-use tariff setup

You’ll need to sign up to a time-of-use (TOU) import tariff – that is, one that comes with peak and off-peak periods.

These rates have been around since 1978, in the form of Economy 7 tariffs – but the spread of smart meters has given rise to a new type of TOU tariff, which targets the increasing number of households with an electric vehicle, battery, or heat pump.

It’s appealing for these customers, who can run their energy-intensive appliances for less, and it suits energy suppliers, as they don’t have to pay peak prices for wholesale electricity as often.

To save money, you just have to shift your consumption. Let’s say you sign up to a TOU tariff with a daily off-peak rate of 20p per kilowatt-hour (kWh) between 12am and 5am.

Using your inverter app, you can set your battery to only import electricity from the grid during this period, then use this low-cost electricity to power your home at other times.

You should be able to fill a 10kWh battery in five hours, for just 20p per kWh. That’s 19% cheaper than the April 2026 price cap of 24.67p per kWh.

Some batteries communicate with the grid smartly, so they can automatically import electricity when it’s cheapest, but even then, it’s worth checking on them every so often.

You could get a better rate if you also had an EV or a heat pump, but you can still save money with just a battery (more on the best tariffs and savings lower down).

Unlike with solar panels though, there’s no way to earn export income. All export tariffs require you to have a system that’s certified by the Microgeneration Certification Scheme (MCS) or Flexi-Orb to generate renewable electricity.

Who are standalone batteries best suited for?

Standalone batteries are a great option for anyone who can’t switch to solar, but still wants to gain some protection against rising energy bills.

There are many homeowners who don’t have a suitable roof for solar panels, for multiple reasons: their roof could be flat, structurally unsound, too small, exclusively north-facing, or covered in dormers and/or velux windows.

For a lot of these households, a standalone battery could unlock serious savings.

How much does battery storage cost?

A storage battery costs about £3,000-7,000.

The price you pay can fluctuate depending on several factors including the battery’s brand, the size of the battery, its quality, the type of battery, and the installation’s complexity.

If you’re thinking of gradually expanding your battery storage over a few years, it’s usually better to instead get it all at once. That way, you only have to pay one installation fee for the entire system.

For more information, read our full guide to battery costs.

How much can you save with a battery?

A home that uses 3,400kWh per year (the national average) and has a 10kWh battery can save £396 annually on Good Energy Heat Pump, as of June 2026.

This tariff provides a daily off-peak rate of 14p per kWh from 5am to 9am and 1pm to 4pm. The household can fill its battery during these periods, giving it 10kWh of cheap electricity to use for the rest of the day.

If the home uses 3,400kWh per year, that works out to 9.3kWh per day on average, meaning 10kWh should be enough to power everything in the home on most days.

Good Energy Heat Pump also comes with a lower standing charge than the April 2026 energy price cap: about 48.01p per day, compared to 57.21p per day. This would save you roughly £34 per year.

Based on a battery that costs £3,000 to £7,000, this means it’ll take between 7.6 and 17.7 years to break even – but this is just an example. Your payback period will depend on the TOU tariff you’re on, your usage, and your battery size.

The crucial part is getting a large enough battery to cover most (or all) of your household’s usage with off-peak electricity. After that, it all comes down to your battery tariff – and there are an increasing number of appealing entries in this field.

To learn more, read our guide to what size battery you need – though as a rule of thumb, a 9-10kWh battery is suitable for the typical home.

Additional savings with virtual power plants

Virtual power plants (VPPs) bring small renewable generators, batteries, and pieces of smart technology into one group that’s controlled by a company.

This firm can charge and discharge your battery (and possibly thousands of others) to the grid for maximum profit, like any other power plant – without you lifting a finger.

In this way, households all over the country can profit from energy trading on a much larger scale than they would be able to individually.

Since VPPs are designed to make money for all participants, this would provide you with additional earnings every year, on top of the estimated savings outlined in the previous section.

It’s difficult to estimate how much you’re likely to earn, but multiple VPPs (including Axle Energy) are guaranteeing that participants will receive around £10 to £20 per month.

And by providing the grid with an extra source of energy when demand surges, VPPs help avoid power cuts, lower everyone’s electricity bills, and allow the grid to expand at a relatively steady, affordable rate.

For more information, check out our guide to virtual power plants.

What are the best tariffs for a battery?

Good Energy Heat Pump is currently the best tariff for homes with standalone batteries.

There are currently only three cost-effective tariffs available in this field – but that’s three more than there were until recently, and the market is set to expand quickly.

Homes with EVs and heat pumps can gain access to dozens of other time-of-use tariffs. We’ve ranked the best EV tariffs and the best heat pump tariffs, so you can maximise your household’s savings.

You could also go for an Economy 7 tariff, but they tend to come with higher off-peak rates – and often higher peak rates – so they’re usually not worth it.

To learn more, check out our guide to the best battery tariffs.

Are there any grants for batteries?

There are no grants for standalone batteries.

You may be able to access several solar panel grants and schemes that include full solar & battery systems, though the requirements are extremely stringent.

These programmes include the Warm Homes: Local Grant, ECO4 (until December 2026), and – if you live in Wales – the Welsh Government Warm Homes Programme and Green Homes Wales.

Or if you have a mortgage with Barclays, Halifax, or Lloyds, you could receive £500 or £1,000 in cashback payments after you get a storage battery installed, thanks to their green home rewards schemes.

Can batteries provide backup power?

Some batteries can provide backup power during power cuts, known as home battery backup.

If the battery you choose comes with this function, you’ll still need an electrician to set it up, as it requires a separate consumer unit (also known as a fuse box) to be installed in your home.

This consumer unit is connected to a dedicated socket, specific circuits within your home, or all your circuits. In a power cut, it’ll send the electricity in your battery to these outlets.

However, the UK’s lack of blackouts means this is only really necessary if you have frequent, debilitating power cuts or medical equipment that must always stay on.

The average home in this country experiences 0.4 outages per year, and loses electricity for roughly 36 minutes in total, according to the latest Ofgem report.

Lengthy power cuts are rare – and in the unlikely situation that one does happen to you, you’ll still only be able to use the electricity you happen to have in your battery when your area goes dark.

How long do batteries last?

Modern lithium-ion batteries, which any good installer should choose for your home, last around 10-12 years.

After this point, they usually need replacing, or they’ll keep degrading until you’re barely saving anything on your energy bills.

Like any appliance, they get less effective over time, in their case due to Solid Electrolyte Interphase growth, lithium plating, and Cathode Material Degradation.

These processes involve the anode being coated with layers of electrolyte and lithium – which reduces its resistance and capacity – and the cathode physically and chemically breaking down.

General wear and tear and particularly cold weather can accelerate this process, which gets quicker over time, with every new cycle taking longer and producing more heat.

For more information, check out our guide to how long batteries last.

Do you need DNO permission for a battery?

You will need to get permission for a standalone battery from your Distribution Network Operator (DNO) – that is, the company that runs the hardware supplying your area of the UK with electricity.

It’s the same situation you’ll encounter if you get solar panels, even though you won’t be exporting electricity with a standalone battery.

Your DNO needs to know you have a device that could potentially send electricity to the grid if the right export tariffs emerge – or if you add solar panels.

Plus, you’ll have a machine that’s capable of importing large amounts of electricity in a short space of time, meaning it could cause sudden, unexpected spikes in demand if the DNO doesn’t know about it.

Which type of permission you need from your DNO depends entirely on the size of your inverter. If its maximum capacity is over 3.68kW, your installer should submit a G99 application after fitting your system, but limiting your inverter’s capacity.

Your DNO will likely take around four to eight weeks to respond. If the application is approved, which most are, you’ll be able to use your inverter’s full capacity – meaning you can charge and discharge your battery as quickly as possible.

Inverters under 3.68kW only require your installer to send in a G98 application, which is simply a notification to your DNO that a new device has been fitted. Unlike a G99, a properly filled-in G98 form can’t be rejected.

A good installer will take care of this for you, without you having to ask or chase them.

Are standalone batteries worth it?

Standalone batteries are well worth it for households, thanks to the growing popularity of TOU tariffs.

And with VPPs also becoming widespread as energy prices continue to stay high, you could save hundreds of pounds on your electricity bills per year.

They’re particularly suited to households that can’t go solar but still want to cut their energy bills, while also gaining some protection against future price rises.

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

Battery storage without solar: FAQs