If you already have solar panels installed, you may be wondering whether you can add a solar battery to your existing set up. The short answer is yes – in most cases, battery storage can be retrofitted to an existing solar PV system, and for many homeowners in the South East, it is one of the most effective ways to increase savings and energy independence.
At SolarTherm UK we regularly upgrade existing systems with modern battery storage, helping customers get more value from the solar they are already generating.
What Does Retrofitting a Solar Battery Mean?
Retrofitting simply means adding battery storage to a solar PV system that is already installed and operational. Instead of exporting excess electricity to the grid during the day, a solar battery stores that energy so it can be used later – typically in the evening, overnight or during periods of high electricity prices.
Can All Solar PV Systems Have a Battery Added?
Most modern solar PV systems can be upgraded with a solar battery without having to upgrade your panels, but the approach will depend on how your system was originally designed and when it was installed.
When assessing the suitability of your existing solar PV system for battery storage, we look at the type of inverter you already have (string, hybrid or microinverters) and the age and condition of your system.
Even older systems installed years ago can usually be adapted using AC-coupled batteries, operating independently of the original inverter.
We also assess your property for available space for a battery and that your electrical capacity and wiring is compliant with current regulations. If you are on the original FiT tariff please discuss battery options with your installer to ensure your new system doesn’t affect your FiT payments.
AC-Coupled vs DC-Coupled Batteries
Understanding the distinction between AC-coupled and DC-coupled batteries is important when retrofitting.
AC-Coupled Battery Storage
- Ideal for existing solar PV systems
- Works alongside your current inverter
- Minimal disruption to the original installation
- Often the most cost effective retrofit option
DC-Coupled Battery Storage
- Typically requires a hybrid inverter
- More common in new installations
- Higher efficiency but often more complex to retrofit
For most retrofit projects in the South East, AC-coupled battery storage is the preferred solution.
Benefits of Adding a Solar Battery to an Existing System
Adding a battery does not increase how much electricity your panels generate, but it dramatically improves how much of that energy you use in your home.
Solar batteries give you higher self-consumption of your self-generated free electricity, lowering electricity bills further, especially in the evenings when electricity rates are at their highest.
A solar battery also gives you the opportunity to use time of use tariffs, this allows you to charge you battery using cheap overnight grid electricity that you can then use during peak periods when your solar is not generating.
For many households, a solar battery transforms solar panels from a daytime only benefit into a 24 hour energy solution.
Is Retrofitting a Solar Battery Worth It?
For homeowners in the South East – where electricity prices remain high and solar generation is strong – battery storage often delivers an excellent return on investment.
Battery retrofits are particularly worthwhile if you are exporting a lot of solar energy during the day and you are mainly home in the evenings. The give you the freedom to use your free electricity generated on your roof top around your lifestyle, saving you money around the clock.
If you are looking to install a heat pump or purchase an EV in the future, solar batteries help you future proof your solar PV system, by giving you the energy storage needed to run your heating and EV in the evenings when solar isn’t generating.
A properly sized battery can significantly shorten your payback period by maximising on site energy use.
What Is Involved in a Battery Retrofit?
A professional retrofit is usually straightforward and completed within a day.
Typical steps include:
- Site survey and system assessment
- Battery sizing based on usage and generation
- Electrical upgrades if required
- Battery installation and commissioning
- Monitoring setup and user handover
At SolarTherm UK, all retrofit work is designed to integrate seamlessly with your existing solar PV system.
Adding Battery Storage in the South East
Homes across Essex, Kent, Surrey and the wider South East are increasingly retrofitting solar batteries as part of their long term energy strategy. With rising electricity costs and greater demand for flexibility, battery storage is no longer just an optional extra – it’s the next logical step.
Final Thoughts
So, can you add a battery to an exiting solar system? In most cases, absolutely, and the benefits are substantial.
If you already have solar panels, adding battery storage allows you to take back control of when and how you use your energy, making your solar PV system work smarter for your home.
Speak to SolarTherm UK today for a free, no obligation quote, tailored to your property, usage and future energy needs. No hard sell, just honest, expert advice.
Your home. Your energy. Your future.
