If you already have solar panels on a Camberley roof, you are far from alone. DESNZ records about 2,178 solar PV installations of every size across Surrey Heath at the end of 2025, as first published, and Surrey Heath Borough Council says more than 500 solar panel and battery installations have been completed on homes in the borough through Solar Together Surrey since its 2021 launch. Plenty of the arrays on Camberley roofs went up without a battery, and the question their owners ask most is whether one can be added. Usually it can. This guide explains how, what changes, and when it is not worth it. For battery sizing and costs in general, see our page on home battery storage in Camberley.
Retrofitting is now the common route nationally, too. DESNZ counted 44,033 MCS-registered battery installations in existing homes in 2025/26, up 81.6% from 24,242 the year before. Those figures cover existing homes only and are statistics in development, but they show that adding storage to a house, often one that already has panels, is now an everyday job.
Why the battery question comes after the panels
Panels make most of their energy when a household needs least. PVGIS 5.3, the European Commission’s solar calculator, puts a 4 kWp south-facing array at the Camberley town-centre point at about 479 kWh in June and about 482 kWh in July, against about 137 kWh in December. Our arithmetic makes December about 29% of June. On a summer day a Camberley array runs well ahead of what the house is using, and without a battery the surplus is exported. A battery keeps some of it for the evening. In winter there is little surplus to keep, which is why a retrofit battery is sized to the summer evening gap rather than to a December shortfall it cannot close. These are figures for an unshaded south-facing roof; on the Bagshot Beds’ sandy soils tall conifers are common, and shading changes the real figure more than the town does.
Two ways to join a battery to a Camberley array
There are two common designs. An AC-coupled battery comes with its own inverter and connects alongside the existing solar inverter, which stays in place; it is usually the simpler retrofit, and it leaves the original array’s wiring alone. A hybrid inverter replaces the existing one and handles panels and battery together; it makes most sense when the existing inverter is near the end of its life, since inverters typically carry shorter warranties than panels, which are designed to last 25 to 30 years. The battery systems we fit are EnSmart and Hanchu, and which design suits your house depends on the age of what is on the roof and where the inverter and consumer unit sit.
Where the battery goes in a Surrey Heath house
Surrey Heath’s housing makes the physical side easier than in many places. At Census 2021, 43.7% of the borough’s 36,005 households lived in detached houses, 25.4% in semis and 12.4% in terraces, and 74.0% owned their home, so the decision usually sits with the person reading this. A detached or semi-detached house often has a garage or utility room within reach of the consumer unit, which keeps the cable run short. Terraces without side access are harder. In one of Camberley’s flats, including The Atrium’s 217 apartments, anything fixed to shared fabric needs the freeholder’s agreement first. And if your home is in one of Camberley’s two conservation areas, the former Staff College on London Road or Upper Gordon Road to Church Hill, keep any external unit off the street-facing walls.
What changes on the paperwork in Camberley
Adding a battery changes what your home can generate, so the network operator has to know. Camberley’s town centre sits in SSEN’s Southern Electric Power Distribution area, about 4.7 km from the nearest other licence area, and GU15, GU16 and GU17 all resolve to SSEN’s southern region in the National Energy System Operator’s data. If the combined system stays within 16 A per phase (3.68 kW), the installer notifies SSEN under G98 before commissioning or within 28 days of it. If the battery takes the total above that line, a G99 application has to be approved before work starts; SSEN says it aims to answer fast-track applications within 10 working days.
If you are paid for exports under the Smart Export Guarantee, ask your supplier whether its terms change once a battery is added. We do not print export rates: they are set by each supplier, must be above zero under Ofgem’s rules, and change at short notice. Any new work we do is certified in the usual way: we are MCS-certified for solar PV and battery storage via NAPIT (member 73495).
What a Camberley retrofit costs, and when it is not worth it
The Energy Saving Trust puts home batteries at £1,500 to £10,000, with a 5 kWh system at around £4,600, a typical home system of perhaps 10 kWh and a lifespan of about 10 to 12 years. It also says fitting storage at the same time as panels costs less than a separate visit later, which is the honest drawback of a retrofit: you are paying for a second visit. The 0% VAT rate applies to a battery fitted on its own until 31 March 2027, reverting to 5% from 1 April 2027. Our post on how long solar batteries last covers the warranty side.
A retrofit is not worth it when the array is small and the house is occupied all day, so there is little surplus to store; when evening use is low; or when the old inverter and wiring would need replacing anyway and the cost stacks up. Surrey Heath’s median EPC score is 69, with detached homes lowest at 66, a reminder that for some Camberley houses insulation is the better first spend. A retrofit battery, like any standard grid-tied battery, also shuts down in a power cut unless backup is designed in. Our guide to what size home battery you need helps you check the size on any quote.
If you are still deciding about panels, our page on solar panels in Camberley covers the roof side, and solar panels in Surrey the county picture.
Sources: DESNZ, Renewable electricity by local authority 2014 to 2025 (published 29 September 2026); DESNZ, MCS-certified domestic battery installation statistics (28 May 2026); Surrey Heath Borough Council news, Solar Together Surrey; PVGIS 5.3, European Commission Joint Research Centre, PVGIS-SARAH3 2005–2023, run 15 October 2026; ONS Census 2021, TS044 and TS054 (Surrey Heath); ONS, Median energy efficiency score, England and Wales (March 2025 edition); Surrey Heath Borough Council conservation-area list; SSEN, Who we are; NESO, GB DNO licence-area boundaries and regional lookup; Energy Networks Association, EREC G98 Issue 2 (10 March 2025); Ofgem, Smart Export Guarantee; Energy Saving Trust, Battery storage (updated 19 August 2026); HMRC VAT Notice 708/6.