An Aldershot roof that already carries panels has done the larger part of a battery system’s job. On the Energy Saving Trust’s national figures, a typical array costs more than a typical small battery, and the generation is already there. What is missing is somewhere to keep the afternoon surplus for the evening. This guide is for owners in GU11 and GU12 who fitted panels first and now want to know whether storage can be added, how it connects and when it is not worth the second visit. For the wider picture, including where a battery fits in North Town terraces and Wellesley new-builds, see our page on battery storage in Aldershot.
There are plenty of arrays to add to. DESNZ records about 1,998 solar PV installations of all sizes across Rushmoor at the end of 2025, as first published, with 10.34 MW of capacity between them. That count covers every scale and both Aldershot and Farnborough, so it is not a count of homes. Nationally, retrofitting storage has become routine: DESNZ counted 44,033 MCS-registered battery installations in existing homes in 2025/26, up 81.6% from 24,242 the year before. Those are statistics in development.
Start with what the array makes, not with the battery
A retrofit battery can only store what the panels make beyond what the house is using at the time. PVGIS 5.3, the European Commission’s solar model, puts a 4 kWp array facing due south in Aldershot at about 482 kWh in June and 486 kWh in July, against about 137 kWh in December and 156 kWh in January. Spread over the month, June is roughly 16.1 kWh a day and December about 4.4 kWh a day (our arithmetic). Ofgem’s typical domestic consumption value from 1 July 2026 is 2,500 kWh a year, about 6.8 kWh a day.
So in summer an unshaded Aldershot array runs well ahead of an average house, and the surplus is exported unless something keeps it. In December there is rarely anything spare. That is why a retrofit battery is sized to the evening gap on a spring-to-autumn day, not to winter. If your array is smaller than 4 kWp, or faces east or west, scale those figures down before anyone talks about capacity.
Three things the survey checks on the existing system
The inverter. Its rating, age and position decide the design. A plain solar inverter cannot charge a battery by itself, so the battery either brings its own inverter or a hybrid replaces the old one.
The consumer unit. In an older North Town or West End house the board may need work before anything new is connected, and that cost belongs in the quote, not in a surprise later.
The cable route. A mid-terrace has no side wall to use, so the battery usually goes indoors near the consumer unit. Four of Rushmoor’s nine conservation areas cover parts of Aldershot, including Aldershot West and Manor Park, and an indoor position keeps the unit out of public view there as well.
AC-coupled or hybrid: the choice in practice
An AC-coupled battery has its own inverter and connects alongside the existing solar inverter, which stays where it is. It leaves the panel wiring alone, which often makes it the simpler retrofit, but it means two inverters on the wall.
A hybrid inverter replaces the existing one and runs the panels and the battery together. It makes most sense when the old inverter is near the end of its life: inverters typically carry shorter warranties than panels, which are designed to last 25 to 30 years. Replacing a tired inverter with a hybrid turns the retrofit into an upgrade rather than an extra layer of kit.
The battery systems we fit are EnSmart and Hanchu. On a Wellesley new-build, check what the developer has already fitted before choosing either route; the newer the wiring, the easier the job.
The SSEN step changes when the battery arrives
Adding storage changes what your home can feed into the network, so SSEN Distribution has to know. Aldershot sits in its Southern Electric Power Distribution area; the town-centre point is about 5.5 km from the nearest UK Power Networks area. The test is the total: the existing solar inverter’s rating plus the battery inverter’s. If the combined figure stays within 16 A per phase (3.68 kW), the installer notifies SSEN under G98, before commissioning or within 28 days of it. Above that, a G99 application has to be approved before work starts, and SSEN says it aims to answer small fast-track applications within 10 working days.
That is one practical point in favour of a hybrid on some Aldershot houses: with one inverter rather than two, the total can sometimes stay under the G98 line, which the design will show. SSEN’s £5.6 million upgrade of the town’s substation switchgear, completed in February 2023 and serving 61,000 customers, strengthened the local network, but it does not change this paperwork.
If you are paid for exports under the Smart Export Guarantee, ask your supplier whether its terms change once a battery is added. We never print export rates: suppliers set them, they must be above zero under Ofgem’s rules, and they change at short notice.
What a retrofit costs, and the second-visit penalty
The Energy Saving Trust puts home batteries at £1,500 to £10,000, with a 5 kWh system at around £4,600 and a typical home system perhaps 10 kWh. 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. DESNZ’s MCS statistics show what retrofit jobs actually cost in 2025/26, equipment, installation and VAT where it applied: on our arithmetic, about £6,570 for the average battery in the 1 to 5.99 kWh band, about £8,520 in the 6 to 10.99 kWh band and about £10,380 in the 11 to 29.99 kWh band. A battery fitted on its own qualifies for the 0% VAT rate until 31 March 2027, then 5%; our guide to VAT on solar panels and batteries has the detail.
When we would tell you not to bother
A retrofit is a weak case when the array is small and someone is home all day, so its output is used as it is made; when your evening use is low; or when the inverter and board both need replacing and the total stacks up. Houses in Rushmoor average a SAP score of 62 against 70 for flats, on the council’s housing strategy figures, so for some owners insulation is the better first spend. And a retrofit battery, like any standard grid-tied battery, shuts down in a power cut unless backup is designed in, with a backup-capable inverter and chosen circuits wired to it.
Our guide to what size home battery you need shows how to read your bills for the evening figure. If your panels are older or you are thinking of extending the array, our page on solar panels in Aldershot covers the roof side, and the Hampshire solar panels hub covers the county picture. We are MCS-certified for solar PV and battery storage, with certification held via NAPIT (member 73495).
Sources: DESNZ, Renewable electricity by local authority 2014 to 2025 (published 29 September 2026); DESNZ, MCS-certified domestic battery installation statistics (28 May 2026); PVGIS 5.3, European Commission Joint Research Centre (PVGIS-SARAH3 2005–2023; 4 kWp, 35°, due south, 14% losses; run 15 October 2026); Ofgem, typical domestic consumption values from 1 July 2026; Rushmoor Borough Council, Housing and Homelessness Strategy 2023–2027 and conservation areas register; NESO, GB DNO licence areas (May 2024); SSEN, Who we are, and news release of 14 February 2023 on the Aldershot switchgear upgrade; Energy Networks Association, EREC G98 Issue 2 (10 March 2025); Ofgem, Smart Export Guarantee; Energy Saving Trust, Battery storage (updated 19 August 2026) and Solar panels: costs, savings and benefits explained (updated 27 August 2026); HMRC, VAT Notice 708/6. Daily figures, percentages and average job costs are our arithmetic on the published figures.