If you installed solar panels between 2010 and 2020, you are likely part of the "Export Generation." You generate free, green power during the day, but send up to 70% of it back to the National Grid. By the time you return home in the evening, the sun has set, forcing you to buy electricity back at peak market rates.
Most older systems export 50-70% of their generation. You are effectively giving away free energy.
We retro-fit a battery to any existing solar PV array. This stores your surplus energy for evening use.
Homeowners often worry that modifying their system will void their lucrative FIT payments. This is a myth.
Your payments are based on your "Total Generation Meter." We install the battery after this meter. You get paid for every unit you generate, whether you store it or use it.
Most older systems use "Deemed Export" (paid for 50% regardless of actual export). You keep this payment AND keep the physical energy. It is financially superior.
As of 2024/25, the UK government applies 0% VAT to retrofit battery storage. You pay no tax on the hardware or the installation labour.
Adding a battery isn't just about "saving solar." It opens up a second revenue stream called Grid Arbitrage.
Instead of buying power at 24p/kWh (average peak rate), you use your stored solar power for free.
In winter, when solar is low, you charge the battery from the grid at night using a smart tariff (e.g., Octopus Agile or Go) for as little as 7p/kWh.
We use two engineering methods to integrate storage, depending on your current inverter's health.
We keep your existing solar inverter and install a standalone battery unit alongside it.
We remove your ageing inverter and replace it with a modern Hybrid Inverter.
Our retrofit solutions are tested and compatible with all major legacy inverter brands found in the UK, including:
To comply with PAS 63100 fire safety regulations, we assess the best location for your battery:
Send us a photo of your inverter. We check compatibility remotely.
We handle the G98/G99 grid application paperwork for you.
Installed in 1 day. Power is off for less than 60 minutes.
We set up the app and link it to smart tariffs like Agile.
No. We can retrofit batteries to systems installed as far back as 2010. If your inverter is extremely old or inefficient, we simply replace it (Method B) as part of the upgrade.
It depends on the hardware. Standard AC batteries often do not. However, if you choose a system with "Emergency Power Supply" (EPS) capability—such as the SigenStor or Tesla Powerwall—we can wire it to keep essential circuits running.
Retrofit pricing varies by capacity, but typically starts from £4,500 (Supply & Install). This includes 0% VAT. To get an exact figure for your home, please request a free quote.
For most systems installed between 2010 and 2020, adding storage is the logical next step to reduce reliance on the grid. It allows you to utilise the energy you are currently exporting, without affecting your Feed-in Tariff.
We advise checking if your system requires a simple add-on (AC) or a full replacement (DC) before deciding.
HSB Renewable Energy are a renewable energy supplier and installer based in North Wales covering areas such as Wrexham, Conwy, Chester & more. Contact a member of the team today to book in your free, no-obligation survey, and to discuss your requirements with one of our experienced specialists.
© 2026 HSB Renewable Energy Ltd | All Rights Reserved
HSB Renewable Energy LTD Unit 1, Pendle Court Evans Way, Shotton, Deeside CH5 1QJ
