Is a Home Battery Worth It? Costs, Lifespan and When It Pays Off

A home battery can be worth it, but the answer depends on what it is paired with.

Energy Saving Trust research published in 2026 found that batteries tend to save more when they run a heat pump on a suitable time of use tariff than when they simply store surplus solar. It also found that adding a battery to solar panels may not pay back on savings alone while export rates stay at current levels.

The Energy Saving Trust currently puts typical costs at around £1,500 to £10,000, and a typical lifespan at about 10 to 12 years.

What a home battery actually does

A home battery stores electricity to use later. It can be charged in two ways:

1. From solar panels, storing daytime surplus for the evening instead of exporting it.

2. From the grid, charging when electricity is cheap on a time of use tariff and discharging when prices are higher.

Battery capacity is measured in kilowatt hours (kWh), which tells you roughly how much electrical energy the battery can store. The Energy Saving Trust says a typical home system might be around 10kWh.

A battery does not usually empty completely. Systems normally stop discharging at a set level, often around 20%, to protect the battery's life. Some energy is also lost when charging and discharging, so stored electricity is slightly less efficient than using it directly.

How much does a home battery cost?

According to the Energy Saving Trust (updated August 2026), battery storage can cost between £1,500 and £10,000 depending on the type and size. A 5kWh system costs around £4,600. These are current typical figures, not fixed prices.

Installing a battery at the same time as solar panels or a heat pump can reduce costs, because installers are already on site.

Installing a home battery currently carries 0% VAT. HMRC guidance confirms this covers:

• batteries added to existing solar panels

• standalone batteries charged from the grid

• batteries charged from both

This applies until 31 March 2027, after which it reverts to 5%.

How long do home batteries last?

The Energy Saving Trust puts the typical lifespan of a home battery at about 10 to 12 years. That is shorter than solar panels, which usually last 25 years or more, so a solar home will normally need to replace its battery before its panels.

Lifespan depends on the battery chemistry, how often it charges and discharges and how deeply it is used. Warranties are set by the manufacturer. When comparing quotes, ask:

• how long the warranty lasts

• what capacity the battery is guaranteed to keep by the end of it

• whether the warranty is limited by a number of charge cycles

When is a battery worth it? Five common scenarios

"Worth it" changes depending on how the battery earns its keep. These are five common situations homeowners weigh up.

Scenario	How the battery earns its keep	What the evidence suggests
Solar panels only, no battery	No battery; surplus solar is exported	The baseline. Export income is reasonable at current SEG rates
Solar panels plus a battery	Stores daytime surplus for evening use	May not pay back on savings alone at current export rates, but reduces dependence on future export rates
Battery on a time of use tariff, no solar	Charges when electricity is cheap and supplies the home at peak times	Can be worthwhile, particularly where there is a large gap between cheap and peak rates
Heat pump plus battery	Stores cheap electricity to run the heat pump outside cheap periods	Energy Saving Trust found batteries perform better with heat pumps than with solar, given the right tariff
Heat pump, solar and battery	Combines all three with suitable tariffs	Around £800 a year lower energy bills in general in Energy Saving Trust modelling, with the best combinations saving around £1,000 or more

These findings come from Energy Saving Trust research published in 2026, based on measured data from 546 homes and around 1.1 million modelled combinations. They are scenario-based results, not savings promises. Real outcomes depend on the tariff, the property and how the household uses energy.

Solar panels only

Without a battery, solar surplus is exported under the Smart Export Guarantee. This is the starting point for judging whether a battery adds enough to justify its cost.

Our guide to whether solar panels are worth it covers solar value, savings and payback in detail.

Solar panels plus a battery

A battery lets you use more of your own solar electricity in the evening.

The Energy Saving Trust's research found that, purely on savings, this may not justify the battery's cost at present. Current export rates allow homes to earn almost as much by exporting surplus at peak times. A battery does make a solar home less dependent on export rates staying where they are.

If you already have panels, see whether you can add battery storage to existing solar panels.

A battery on a time of use tariff, with no solar

A battery does not need solar panels. On a time of use tariff, it can charge when electricity is cheapest, often overnight, and supply the home during more expensive periods. When the battery is full, it simply stops charging until the next cheap period.

How well this works depends on the gap between the tariff's cheap and peak rates and on how much electricity the home uses at peak times.

A battery with a heat pump

This was one of the clearest findings in the Energy Saving Trust research. A heat pump uses a lot of electricity, and a battery lets it run on electricity bought at off-peak prices rather than peak rates.

The same research found that heat pumps on a standard flat-rate tariff often cost as much or more to run than an efficient gas boiler, and that a suitable tariff made a significant difference. A battery increases how much of a heat pump's electricity can come from cheap periods.

For more on this, see our guide to heat pump running costs.

If you are also considering a heat pump, check the grants currently available for heat pumps.

Heat pump, solar and battery together

The Energy Saving Trust called this the "integrated electric home". With the right tariffs, bills fell by around £800 a year in general in its modelling. Results in individual homes will vary with the tariff, the property and how energy is used.

This combination is the most expensive to install, and it is rarely done all at once. Many households add each technology in stages.

Will a battery keep the power on during a power cut?

Not necessarily. Many home battery systems do not supply the house during a power cut unless they have been specifically set up to do so, and switchover is not always automatic.

Whether a battery can provide power during an outage depends on:

• the inverter

• how the system is wired

• whether a backup function has been configured

• which circuits are included

Where backup is available, it may only cover certain circuits rather than the whole home. If this matters to you, ask the installer directly whether the proposed system will supply power during a power cut and which circuits it would cover.

When a battery may not pay back

A battery is less likely to be worthwhile when:

• the household uses little electricity in the evening or at peak times

• the home is on a flat-rate tariff with no cheap period to charge from

• the battery is much larger than the home can make use of

• the aim is purely to store solar surplus while export rates remain good

In those situations, a battery may still offer other benefits, but the financial case is weaker.

Replacing or upgrading a battery later

Because batteries usually last 10 to 12 years, a battery installed with solar panels is likely to need replacing within the panels' lifespan.

Before buying, ask:

• whether capacity can be added later

• whether the battery is compatible with other equipment you might add, such as a heat pump or an electric car charger

Getting advice on whether a battery suits your home

The value of a battery depends on your electricity use, your tariff and the other technologies in your home, now and in future.

Puraflow Renewables is MCS certified and installs battery storage alongside solar PV and air source heat pumps, so a battery can be considered as part of your wider energy setup.

If you already have solar panels, our guide to adding a battery to existing panels explains the compatibility and sizing checks.

Frequently asked questions

Can I sell electricity from my battery back to the grid?

Surplus solar can be exported when your battery is full through a Smart Export Guarantee tariff. Some more advanced tariffs also let homes export stored electricity at peak times. Check the terms of any tariff you are considering.

Can I use my electric car as a home battery?

Generally not yet. The Energy Saving Trust notes that bidirectional charging, which lets a car supply power to a home, is being trialled but is not widely available.

Is there a grant for home batteries?

There is no general grant for home batteries at present. The Warm Homes Plan is set to include fully funded support for low-income households and low or zero-interest loans for other homeowners, with details still being developed. Installation currently carries 0% VAT until 31 March 2027.

Where does a home battery go?

Batteries are typically installed in a garage, utility room or on an external wall, depending on the model. The Energy Saving Trust says a typical unit measures around 100cm by 60cm by 25cm.