Battery storage in Sevenoaks

Sevenoaks at a glance

Four Sevenoaks homes in five heat with gas

At the 2021 Census, 80.6% of the 8,207 households in the four wards whose names begin with Sevenoaks (Town and St John’s, Kippington, Eastern and Northern) heated with mains gas and nothing else, against 72.3% across Sevenoaks District. Oil alone heats 6.7% of the district’s households but only 1.0% of the town’s. Those four wards leave out Riverhead, Dunton Green, Seal and Sevenoaks Weald, which are counted separately.

So in most Sevenoaks homes a battery does nothing for the heating. Its job begins as the panels tail off in the late afternoon: lights, cooking and appliances run on electricity the roof made at midday instead of electricity bought from the grid. The 6.5% of households heating with electricity alone are different. Their demand peaks in winter, when a TN13 roof generates least, so their battery is sized from twelve months of bills, not from a summer evening.

36.9% with four bedrooms or more

Sevenoaks homes run large. At the Census, 36.9% of households in the four wards had four or more bedrooms, against 21.1% across England, and 34.3% lived in a detached house. In the 12 small areas that best fit the wards, the Valuation Office Agency puts 28.7% of homes in council tax bands G and H, where England’s share is 4.1%.

A bigger house does not make the case for a battery on its own. The value table further down models a home using 2,500 to 2,999 kWh a year and occupied for half the day, on the 4,192 kWh a year PVGIS gives an unshaded 4 kWp south-facing array at TN13 1AA. On those inputs, a 10 kWh battery lifts the solar electricity used in the house from 755 kWh to 2,348 kWh a year. A year of bills shows where a Sevenoaks household sits against that usage band; a bedroom count cannot. Our guide prices, 4kWp to 8kWp and each with 10kWh of storage, are on solar panel cost in Kent with their conditions, and our guide to whether solar is worth it in Kent works the Sevenoaks payback through with and without a battery.

Storage for arrays already on the district’s roofs

DESNZ counted 3,282 solar PV installations in Sevenoaks District at the end of 2025, 84% more than the 1,783 at the end of 2020. The district runs from Swanley to Edenbridge and Westerham, so the count is not the town’s own, but 1,783 arrays were already in place more than three years before 1 February 2024, the date from which a battery added on its own to existing panels qualified for the VAT zero rate.

On a house with an older array, our survey looks at the existing installation and its inverter arrangement first, and confirms what can be integrated safely before anything is quoted. Installation, commissioning and the app monitoring set up at handover are on our battery storage installation page.

TN13 on the South Eastern licence: G98 or G99

TN13 1AA sits in Elexon grid supply point group _J, which puts Sevenoaks on UK Power Networks’ South Eastern Power Networks (SPN) licence. The connection rules UK Power Networks applies, G98 and G99, count a battery alongside the panels when they size a home’s generation. At 16 A per phase or less, which is 3.68 kW on a single-phase supply, UK Power Networks is notified within 28 days of commissioning under G98; anything larger needs a G99 application, accepted before the system is connected.

For a Sevenoaks house adding storage, the inverter layout decides the route. A battery on its own inverter adds that rating to the solar inverter’s, so panels that sat inside G98 can tip over it; a hybrid inverter running panels and battery together counts at its own rating only. Our guide-priced systems include the DNO G98/G99 paperwork as standard, whichever route applies.

Landlords, freeholders and listed houses

Two Sevenoaks households in three own their home (65.9%, against 71.5% across the district), and one in five (20.3%) rents privately, half as many again as the district’s 13.4%. A battery is fixed to the building, so a private tenant starts with the landlord, and the 12.1% in social housing, mostly with housing associations rather than the council, start with their provider. A quarter of households live in a flat, where the freeholder usually controls the roof that panels need.

Historic England’s list holds 189 entries inside the four wards, 2 at Grade I, 12 at Grade II* and 175 at Grade II, and 114 of them sit in Town and St John’s. Sevenoaks District Council’s listed-building guidance says works to a listed building usually need listed building consent, and that the whole building is covered, not only its front. In a listed Sevenoaks house, then, raise the battery position and its cable route with the council before either is fixed, even indoors.

Eight of the district’s 41 conservation areas fall in or touch the wards, from Sevenoaks High Street, designated in 1971, to Hartslands in 2011. The council, whose offices are on Argyle Road, says on its conservation-area page that even relatively minor works such as cladding or altered doors and windows can affect an area’s character, and advises contacting its Planning Team first. An inverter or battery planned for an outside wall there is worth that call; in an unlisted house, an indoor spot such as a garage keeps it off the street scene.

0% VAT until 31 March 2027, and the run from Keston

Since 1 February 2024, HMRC’s VAT Notice 708/6 has listed batteries as energy-saving materials in their own right, so one retrofitted to panels already on a home’s roof is zero-rated, as is one fitted with new panels. The 0% rate runs until 31 March 2027, and the reduced rate of 5% applies from 1 April 2027; your written quotation confirms the VAT on your job. Whether any scheme could help a Sevenoaks household is covered on solar and battery grants in Kent.

We are based at Glebe Farm Business Park, Keston, 8.6 miles (13.8 km) from central Sevenoaks as the crow flies and further by road. For the wiring side of a TN13 home, from a consumer unit to an EICR, see electrician in Sevenoaks.

What a battery could be worth on a Sevenoaks roof

PVGIS 4,192 kWh a year for this town. Illustrative first-year figures, not a guarantee: import 26.32p/kWh (Ofgem energy price cap, 1 Oct – 31 Dec 2026, electricity, Direct Debit, GB average unit rate (26.32p/kWh)); export 12p/kWh (Outgoing Octopus Smart Export Guarantee tariff, 12p/kWh variable (Octopus customers with a half-hourly export meter), read 15 Oct 2026); self-use from MCS MGD 003 Issue 2.0 self-consumption tables, 2,500–2,999 kWh use, occupied half the day. Coutts' guide price for 4kWp with 10kWh battery capacity is from £9,500, inclusive of VAT at 0% (the relief runs to 31 March 2027). Full worked example: solar panel cost in Kent; schemes: solar and battery grants in Kent.

What every battery storage job includes

• 10kWh battery capacity included in every guide-priced system
• Installed and commissioned alongside the array by our own engineers
• App monitoring set up at handover so you can see storage and use
• Retrofit to an existing solar array is possible — we survey first