Battery Storage for Solar Panels in the UK: What You Need to Connect

Many UK homeowners want to use more of the electricity their solar panels generate, particularly after sunset when household demand often rises. A battery can reduce grid reliance, improve control over energy use and, depending on the system, support limited backup power during an outage.

This guide explains what you need to connect battery storage for solar panels in the UK, including compatible inverters, circuit protection, metering requirements, installation locations and DNO considerations. Choosing the right battery system involves more than selecting a capacity, as the setup must be professionally designed and connected by a suitably qualified installer.

What do you need to connect battery storage to solar panels in the UK?

To connect battery storage to solar panels in the UK, you generally need a compatible battery, an inverter, consumer-unit connection, circuit protection, metering, monitoring equipment and DNO notification or approval. A qualified installer will confirm whether your existing solar system can support the proposed battery.

The exact equipment depends on whether you are:

• Retrofitting a battery to existing solar panels.
• Installing solar panels and storage together.
• Adding backup power for selected circuits.
• Using the battery with a time-of-use electricity tariff.

Your installer should assess the existing solar inverter, battery charging method, consumer unit, meter arrangement and available installation space before recommending equipment.

Can you add a battery to existing solar panels?

Yes, you can usually add a battery to existing solar panels, but compatibility should be checked first. Most UK solar PV systems can be upgraded with battery storage, even if the panels and inverter were installed years ago.

Before installation, an installer will check your solar array output, inverter model, consumer unit, available space and whether additional equipment is required. In some cases, the inverter may need to be upgraded.

Retrofit battery storage

For existing solar systems, AC-coupled battery storage is a common retrofit option. It uses a separate battery inverter connected alongside the existing solar inverter, which means you may not need to replace a working solar inverter.

AC coupling can also allow grid charging, depending on the system design and tariff. However, it may involve extra conversion steps compared with DC-coupled systems, resulting in some efficiency loss.

New solar and battery installations

When solar panels and batteries are installed together, a hybrid inverter is often used to manage solar generation, battery storage and grid electricity in one system.

DC-coupled systems can offer efficiency advantages by storing solar energy directly before conversion for household use. However, the best choice depends on your panels, battery compatibility, budget, backup needs and future expansion plans.

Inverter, consumer unit and meter requirements

The inverter, consumer unit and metering equipment work together to move electricity safely between the solar panels, battery, home and grid. The design must comply with relevant UK electrical requirements, including BS 7671, and must be suitable for the property’s existing wiring.

Hybrid inverter and AC-coupled inverter options

A hybrid inverter solar battery system combines solar and battery management in one device. It converts the panels’ DC electricity into AC for household use, while controlling when surplus energy charges the battery or is exported.

An AC-coupled system uses the existing solar inverter and a separate battery inverter. This is often easier when the solar PV system is already installed because the original inverter can remain in service if it is compatible.

An installer should also confirm the battery’s usable capacity, maximum charge and discharge power, depth of discharge, warranty and whether it supports export charging or backup operation.

Consumer unit connection and circuit protection

The battery normally connects to the property through a dedicated circuit from the consumer unit. The installer will select appropriate breakers and protection based on the equipment and the characteristics of the installation.

Depending on the design, this may include:

• A dedicated MCB or RCBO.
• A bidirectional RCBO where the device requires current to flow in both directions.
• RCD protection where appropriate.
• AC and DC isolation switches.
• Clear labels for the battery, inverter and shutdown points.

The electrician should check the consumer unit’s capacity, earthing arrangement and existing circuits. All isolation points and warning labels should remain accessible so future electricians can work safely.

Smart generation meter, DTSU meter and CT metering

Metering tells the energy-management system where electricity is going. A generation meter can record solar output, while a smart electricity meter measures electricity imported from and exported to the grid.

A DTSU meter is a type of energy meter used with some systems to measure power flow. CT clamps, or current transformers, monitor electricity passing through cables without needing to interrupt them.

Correctly positioned CT metering helps the battery decide whether to charge from surplus solar, discharge to meet household demand or limit exports. Poorly installed or configured sensors can produce inaccurate app readings and incorrect battery behaviour.

Do you need DNO approval for solar battery storage?

In many cases, yes. A grid-connected battery system generally needs notification to, or approval from, your Distribution Network Operator (DNO). The installer normally handles the DNO notification solar battery process and confirms which application route applies.

The DNO checks that the installation will not create unacceptable risks for the local electricity network. Requirements can vary by region and system design, particularly where the battery can export electricity independently of the solar panels.

G98, G99 and G100 in simple terms

G98 generally applies to smaller installations that meet specific technical limits and can usually be notified after installation.

G99 is typically required for larger or more complex systems and usually involves approval before installation begins.

G100 relates to export limitation. If a battery system uses export controls to keep electricity sent to the grid within an agreed limit, the installer may need to provide evidence that the equipment works correctly.

The correct DNO process depends on the total system capacity, phase connection, export settings and local requirements. Do not assume that a quotation stating “DNO covered” includes all necessary approvals — ask your installer what documents will be provided after installation.

Electrical certificates and installer paperwork

After a solar battery installation UK project, ask for a complete handover pack. This should normally include:

• An Electrical Installation Certificate.
• DNO notification or approval confirmation.
• MCS documentation, where applicable.
• Battery and inverter warranties.
• Product datasheets and user manuals.
• Monitoring app access details.

Keep these documents with your household records. They may be useful for warranty claims, insurance questions, future electrical work or selling the property.

Safe battery locations and UK installation rules

A battery’s location affects fire safety, ventilation, access, maintenance and the installer’s ability to meet current guidance. The most convenient space is not necessarily the safest or most suitable one.

PAS 63100 fire safety guidance

PAS 63100:2024 provides guidance for the installation of electrical energy storage systems in buildings, including considerations around fire safety and placement. Installers should assess ventilation, separation from hazards, access and the building’s escape routes.

The battery should be mounted securely on a suitable, fire-resistant surface that can support its weight. Equipment should not obstruct doors, windows or escape routes, and the installation must allow safe isolation and maintenance.

PAS 63100 is guidance rather than a substitute for a site-specific design. Your installer should explain how the proposed arrangement addresses the relevant requirements.

Suitable indoor and outdoor locations

Common locations for solar battery storage installations in the UK include:

• Garages with suitable ventilation and access.
• Utility rooms with adequate space and airflow.
• Purpose-built external battery enclosures.
• Other non-habitable areas approved by the installer.

Outdoor equipment must be designed for external conditions and protected from flooding, impact, excessive heat and unauthorised access. Weather resistance alone does not make every external location suitable.

Locations installers usually avoid

Installers commonly avoid lofts, bedrooms, stairwells, escape routes and small cupboards. These areas can create challenges involving heat, access, fire risk and evacuation.

A competent installer must assess the individual property rather than applying assumptions. Existing batteries are not automatically required to move because guidance changes, but an inspection may be sensible if you have concerns about location, ventilation or condition.

Step-by-step installation process and homeowner checks

A typical installation moves from a technical survey to system design, installation, commissioning and handover. The process can take longer if the consumer unit needs upgrading or DNO approval is required before work starts.

Home survey and energy assessment

Before recommending a battery system, the installer should assess your electricity usage, solar generation and existing electrical setup. This helps determine the right battery size, inverter compatibility and installation requirements.

The survey should cover:

• Existing solar inverter and panel output.
• Electricity consumption patterns and smart-meter data.
• Consumer unit, earthing and cable routes.
• Electricity meter and DNO connection.
• Proposed battery location.
• Internet or communications availability.

The installer may also ask whether you need backup power, want to use a time-of-use tariff or plan to expand your solar system in the future.

System design and equipment selection

The system design should match battery capacity with your household demand and available solar generation. A battery that is too small may leave excess solar energy unused, while an oversized system may increase upfront costs and extend the payback period.

Your quotation should clearly specify the main components, including:

• Battery capacity and usable capacity.
• Solar or hybrid inverter.
• Protection devices and isolation equipment.
• Metering and CT clamps.
• Monitoring system.
• Installation, commissioning and aftercare costs.

Check whether the quote includes additional costs, such as electrical upgrades, DNO paperwork, VAT and any backup power equipment.

For homeowners looking to add storage to an existing solar setup, the Anker SOLIX Solarbank 4 E5000 Pro is designed as a flexible battery storage option. It helps capture surplus solar energy that would otherwise be exported to the grid and allows homeowners to use more of their own solar generation later in the day. With expandable storage, intelligent energy management and compatibility with smart metering solutions, it can suit households looking to improve self-consumption without replacing their entire solar setup.

Professional installation and commissioning

During installation, the electrician fits the battery, inverter and required protection equipment according to the approved design. They also complete the necessary electrical connections, testing and commissioning.

Before handover, the installer should check that the system operates correctly, explain basic controls and provide important documents, including warranties, manuals and monitoring access details.

Conclusion

Understanding what you need to connect battery storage for solar panels in the UK starts with choosing the right inverter, ensuring a suitable consumer-unit connection, accurate metering, reliable monitoring, safe mounting and an appropriate installation location. Grid-connected systems may also require DNO notification or approval, while certificates, warranties and user instructions should be provided at handover. A professional survey before purchase can help confirm compatibility, battery location and the specific requirements of your home energy system.

FAQs about battery storage for solar panels in the UK

Can I install a solar battery myself in the UK?

In most cases, installing a solar battery is not a suitable DIY project in the UK because it involves electrical connections, protection equipment and grid requirements. It involves high electrical currents, battery-specific controls, protective devices and grid-connection requirements. A qualified electrician must design, install and test the system to the relevant UK standards. DIY work may invalidate warranties, insurance and DNO compliance.

Do I need a smart meter for solar battery storage?

Not always, but a smart meter is often useful and may be required for certain tariffs. It records electricity imported from and exported to the grid, while separate CT meters can control battery operation. Your installer and supplier can confirm whether your existing meter supports the tariff and export arrangement you want.

Can solar batteries be installed outside in the UK?

Yes, solar batteries can be installed outside in the UK when the equipment is approved for outdoor use and protected in a secure, weather-resistant enclosure. The location must also address ventilation, flooding, temperature, impact and fire safety. Your installer should confirm the enclosure, mounting surface and cable routes are suitable.

How long does solar battery installation take?

Many domestic battery installations take one to two days once the equipment and approvals are ready. The work may take longer if the consumer unit needs changes, cables are difficult to route, backup circuits are added or DNO approval is required before installation. Paperwork can continue after the physical work is complete.

How much battery storage do I need for my solar panels?

Most homes need a battery sized around their surplus solar generation and evening electricity use, rather than simply choosing the largest available model. A professional will review seasonal output, daily consumption, inverter power and tariff plans. Typical domestic systems may be around 5–15kWh, but the suitable capacity varies considerably.