BESS Retrofit — Add Battery Storage to Your Existing Solar PV System
Already have commercial solar panels? Novalux Solar retrofits battery energy storage systems to existing solar PV installations, dramatically improving your returns and energy independence.
Thousands of commercial solar PV systems installed across the UK are operating without battery storage — exporting surplus generation at low rates while their owners still pay peak prices for evening electricity. A BESS retrofit changes that. Novalux Solar is a specialist commercial BESS retrofit installer, working with existing systems from any inverter manufacturer and any installation era.
The Novalux Solar BESS retrofit process
Site assessment and data analysis
Our engineers review your existing system documentation, inverter specifications and half-hourly meter data to build a precise picture of your export profile and demand patterns.
Financial modelling
We model multiple battery size options against your actual data, producing a 25-year cashflow showing payback period, NPV and annual savings for each option.
DNO notification or G99 application
Novalux Solar handles all DNO interaction, including G98/G99 notifications, protection relay requirements and any export limitation discussions.
Installation
Our NICEIC-accredited team installs the battery modules, inverter/charger, protection equipment and monitoring system — typically in one to three days with minimal operational disruption.
Commissioning and optimisation
Your BESS is configured with a charge/discharge strategy tailored to your tariff and demand profile. Remote monitoring is active from day one.
AC-coupled vs DC-coupled retrofit
AC-coupled (recommended for most retrofits)
The battery and its dedicated inverter/charger connect on the AC side of your existing installation — after your solar inverters. Compatible with virtually all existing commercial inverter brands including SolarEdge, SMA, Fronius, Huawei, ABB and Sungrow. No changes to your existing solar equipment are required, preserving existing warranties and minimising installation cost and time.
DC-coupled (for specific applications)
A DC-coupled retrofit replaces your existing inverters with a hybrid system managing both solar and battery on the DC side. More efficient but more disruptive. Novalux Solar will advise whether the efficiency gain justifies the additional cost and downtime for your specific system.
Indicative BESS retrofit pricing
AC-coupled retrofit installed. Suitable for systems up to ~200kWp.
Commercial system installed. Suitable for 200–750kWp solar arrays.
Containerised BESS. Industrial and large commercial applications.
FiT recipients: If your existing solar system still receives Feed-in Tariff payments, adding a battery does not affect your FiT entitlement when installed correctly. Novalux Solar confirms your FiT status as part of the assessment process.
What existing systems are compatible?
AC-coupled BESS retrofit is compatible with the vast majority of UK commercial solar PV systems. This includes older string inverter systems installed during the Feed-in Tariff era (2010–2019) — which represent the largest pool of retrofit candidates in the UK. Systems using inverters from SolarEdge, SMA, Fronius, Huawei, ABB, Sungrow, Solax and most other brands are suitable.
Completed BESS retrofit projects: Novalux Solar has completed combined solar and battery installations for LWC Drinks Liverpool (210kWp + 258kWh), White Barn/Charles Jackson Ltd (417kWp + 500kW/600kWh), Wellington Farm (solar + batteries) and Link Hall Farm (81kWp + 200kWh) — demonstrating our capability across a wide range of commercial and agricultural applications.
Beyond cost savings — additional value from BESS retrofit
- Backup power capability for critical loads during grid outages
- Peak demand shaving to reduce capacity charges on HH-metered sites
- Eligibility for National Grid ESO grid services revenue (Dynamic Containment) for larger systems
- Improved self-consumption ratio — typically from 40% to 70–85%
- Reduced Scope 2 carbon emissions for ESG reporting
Find out if your solar system is ready for a BESS retrofit
Send us your system details and we’ll provide a Quick Quote with financial modelling within 24 hours.
Request Your BESS Retrofit Quote