Solar Panel Battery Storage: Is It Worth It?

If you are thinking about installing solar panels in Kent, you may have come across the option to add a battery storage system at the same time. It is an increasingly common choice, and for many homeowners it makes a significant difference to the overall value of going solar. But is solar battery storage actually worth it for your home? This guide looks at how battery storage works, what it costs, and when it makes the most sense to include one.

How does solar battery storage work?

Solar panels generate electricity during daylight hours. Without a battery, any electricity you do not use in the moment is either wasted or exported to the grid via the Smart Export Guarantee. The problem is that most households use more electricity in the mornings and evenings than they do during the middle of the day when the panels are generating at their best.

A solar battery storage system captures that surplus daytime generation and holds it until you need it later in the day. This means the electricity your panels produce in the afternoon can power your home in the evening, rather than being sent back to the grid for a fraction of what you would pay to buy it back.

What are the benefits of solar battery storage?

The primary benefit is that you increase your solar self-consumption rate. Without a battery, a typical household might self-consume around 30 to 40 percent of the electricity their panels generate. With a battery, that figure can rise to 70 percent or higher, depending on the size of the battery and your usage patterns. The more of your own solar electricity you consume, the less you need to buy from the grid, and the lower your energy bills.

Battery storage also provides a degree of energy independence. In the event of planned or unplanned power cuts, some battery systems can provide backup power for essential circuits in your home, which is a feature that a growing number of homeowners in Kent consider valuable.

There is also a future-proofing argument. As time-of-use tariffs become more widely used, households with batteries can charge them during cheaper overnight periods and then use that stored electricity during peak-rate hours, adding further savings on top of what solar alone provides.

How much does solar battery storage cost?

Battery storage is an additional cost on top of your solar panel installation. In 2026, a quality home battery system installed in Kent typically costs between £2,000 and £4,500 depending on capacity and brand. The most common battery sizes for residential use are in the 5kWh to 10kWh range.

The good news is that, like the solar panels themselves, battery storage installed alongside a solar system currently benefits from zero-rate VAT for residential properties. This reduces the effective cost compared to what it would have been in previous years.

Whether the additional cost is worthwhile depends on your household energy usage profile, the size of your solar system, and your current electricity tariff. A larger household that uses significant electricity in the evenings will typically see a better return from battery storage than a household that is mostly out during the day.

Can I add a battery to my existing solar panels?

Yes, in most cases it is possible to retrofit a battery storage system to an existing solar installation. The compatibility depends on the type of inverter you have installed and the age and specification of your current system. AC-coupled batteries can generally be added to most existing solar setups, while DC-coupled systems are more efficient but may require a compatible or new inverter.

If you have an existing solar panel system in Kent and want to explore adding battery storage, Transcrew can assess your current setup and advise on the most suitable option for your property.

What size battery do I need?

The right battery size depends on two things: how much electricity your panels typically generate that is surplus to your daytime needs, and how much electricity you use during the evenings and overnight. A home with a 4kWp solar system and a two to three person household would generally find a battery in the 5kWh to 7kWh range fits well. Larger households, or those with electric vehicles or heat pumps, may benefit from greater capacity.

Getting the sizing right matters. A battery that is too small will fill up quickly and still export a lot to the grid, while an oversized battery may never fully charge and deliver a poor return on the additional spend. A proper assessment from an experienced installer is the best way to arrive at the right recommendation.

Solar panels with battery storage versus solar panels alone

Solar panels on their own are a proven, cost-effective investment for most Kent homeowners. Adding battery storage improves the financial case further by maximising the use of your own generation, but it does extend the overall payback period due to the additional upfront cost.

For many households, particularly those who are at home in the evenings, have an EV to charge, or use an air source heat pump, the combination of solar panels and battery storage represents the strongest long-term investment. For others, particularly those with very low evening electricity usage, solar panels alone may deliver the most straightforward return.

Talk to Transcrew about solar battery storage in Kent

Transcrew installs solar panel and battery storage systems across Kent, working with homeowners in Thanet, Canterbury, Maidstone, and surrounding areas. We will assess your property, review your energy usage, and give you an honest recommendation on whether battery storage is the right addition for your home.

To find out more, get in touch with Transcrew or visit transcrew.co.uk/battery-storage-kent to learn more about our solar battery storage installations.