Should I get a solar battery with my solar panels?

Adding battery storage to your solar panel system can help you make greater use of the electricity your home generates and reduce the amount of electricity you need to buy from the grid.

Solar panels generate electricity during daylight hours, but this doesn't always coincide with when your household uses the most energy. A battery allows you to store some of the electricity you don't use immediately and use it later — for example, during the evening when your solar panels are generating little or no electricity.

Whether a battery is right for you will depend on how much electricity you use, when you use it, the size of your solar system, your electricity tariff and the cost of the battery.

What are the benefits of a solar battery?

Use more of the electricity you generate

Without battery storage, surplus electricity that isn't being used by your home can be exported to the grid. A battery allows you to store some of that surplus electricity and use it later.

Reduce your reliance on the grid

Using stored solar electricity during the evening or at other times when your panels aren't generating enough can reduce the amount of electricity you need to purchase from your energy supplier.

Make use of cheaper electricity tariffs

Some modern battery systems can also charge from the grid. If you have a suitable time-of-use tariff, this can allow you to charge your battery when electricity is cheaper and use the stored electricity when grid prices are higher.

Greater control over your home energy

Many modern solar and battery systems include apps that allow you to see how much electricity your panels are generating, how much your home is consuming and when your battery is charging or discharging.

Potential backup during a power cut

Some battery systems can provide backup electricity if there is a power cut. However, this isn't standard with every installation and may require additional equipment, so check this with your installer if backup power is important to you.

How much does a solar battery cost?

Battery prices vary depending on capacity, manufacturer, technology and installation requirements. A typical home battery can cost several thousand pounds, with larger or premium systems costing considerably more.

Rather than simply choosing the largest battery available, it's important to select a system that suits your home's electricity consumption and the amount of electricity your solar panels are likely to generate.

If you're considering a new solar installation, it can be useful to ask for two quotations:

Solar panels only

and

Solar panels + battery storage

This allows you to compare the additional investment against the potential benefits of storing more of the electricity you generate.

How long do solar batteries last?

Many modern home batteries are designed to operate for around 10–15 years, although actual lifespan will depend on the battery technology, how frequently it is charged and discharged, operating conditions and the manufacturer's specification.

Battery warranties also vary, so it's worth comparing both the warranty period and the manufacturer's guaranteed performance when choosing a system.

Are solar batteries worth it?

There isn't one answer that applies to every household. A battery may be particularly attractive if you generate significant amounts of surplus solar electricity during the day but use more electricity during the evening.

The economics can also be influenced by smart electricity tariffs that allow compatible batteries to charge when electricity is cheaper.

When assessing a battery, consider:

The cost of the battery and installation
Battery capacity
Your household electricity consumption
When you use electricity
How much surplus solar electricity you're likely to generate
Your electricity tariff
Available export tariffs
Battery lifespan and warranty

A reputable installer should be able to model how a solar and battery system could perform based on your individual property and electricity usage.

Do I need a solar battery to sell excess electricity through the Smart Export Guarantee?

No. You don't need a battery to export surplus solar electricity to the grid.

The Smart Export Guarantee (SEG) allows eligible households with renewable electricity generation to receive payment from an SEG supplier for electricity exported to the grid.

Solar panels without a battery

If your solar panels are generating more electricity than your home is using, surplus electricity can be exported to the grid.

If your system meets the relevant requirements and you have an SEG agreement in place, your SEG supplier can pay you for the electricity you export.

Solar panels with a battery

With battery storage, you have another option.

Instead of immediately exporting all of your surplus solar electricity, some of it can be stored in your battery and used later.

Once your battery is sufficiently charged, additional surplus electricity can still be exported to the grid.

Depending on your equipment and energy tariff, some systems can also be configured to make more sophisticated decisions about when electricity is stored, used or exported.

Should I store my electricity or export it?

This depends on the relative value of the electricity. Using your own solar electricity means you avoid buying that electricity from the grid. Exporting it means receiving your applicable export tariff.

The best option therefore depends on your import electricity price, export tariff, battery efficiency, usage pattern and when electricity is required. This is one reason modern solar systems are increasingly considered as complete home energy systems rather than simply a collection of solar panels.

Solar generates the electricity.
Your home uses what it needs.
Your battery can store some of the surplus.
Anything remaining can potentially be exported to the grid.

Find the right solar and battery system for your home

The right combination of solar panels and battery storage will depend on your property, electricity consumption and budget.

Comparing options from experienced providers can help you understand the appropriate system size, likely generation, battery capacity, installation cost and potential savings before deciding whether to proceed.