DVLA records about 5,428 privately kept plug-in vehicles across the London Borough of Sutton at the end of June 2026, up from 4,264 a year earlier. That is a rise of about 27% in twelve months on our arithmetic. It does not count chargers or households, and it covers the whole borough rather than Carshalton alone, but it does show that more Sutton households now have a car to plug in. If you are one of them, the question is how a charger, a battery and panels fit together. Our page on home battery storage in Carshalton covers the battery side in full.
We use the privately kept figure deliberately. Sutton’s all-keeper total, about 6,600 plug-in vehicles, includes company-registered vehicles, which are counted at the keeper’s registered address rather than where the car is kept, so it says less about Carshalton households.
Three pieces, three different jobs
Panels make electricity in daylight. A battery moves it from the afternoon to the evening. A charger puts it into the car. In a Carshalton home with all three, the most useful order is usually: run the house from the panels, charge the car from any surplus while it is at home, top up the battery with what is left, and use the battery for the house after dark. On a south-facing SM5 roof, most of that solar car charging happens between spring and autumn, as the PVGIS months below show.
The sizes explain why. The Energy Saving Trust suggests a typical home battery might be 10 kWh. A 60 kWh car charge is six times that on our arithmetic. Emptying a home battery into a car moves a small amount of energy and leaves the house buying from the grid that evening. Overnight, an off-peak EV tariff prices units well below the 26.32p per kWh October to December 2026 cap rate, which is usually the cheaper way to fill a car in Sutton outside the summer months. Every new home chargepoint sold in Great Britain has had to be smart since 30 June 2022, which is what lets it be scheduled for those hours.
The fuse comes before the kit
A 7.4 kW charger draws 32 A continuously. Most homes have a 60 A, 80 A or 100 A main fuse, and load management, a current sensor on the incoming supply that throttles the charger when the house is busy, usually avoids a supply upgrade. UK Power Networks, which runs the network in SM5, says it can upgrade a main fuse from 30 or 60 A to 80 or 100 A, and that a looped supply shared with a neighbour has to be re-planned with both households and may carry a charge. Our post on whether your fuse will take a 7 kW EV charger goes through the checks.
A battery adds a separate check. Under G98, generation and battery storage up to 16 A per phase, 3.68 kW, is notified to the network operator; above that, G99 approval comes first. Carshalton’s town centre sits in UK Power Networks’ South Eastern Power Networks licence area, about 2.4 km from the London Power Networks boundary, so check your postcode with its area checker. Every new chargepoint is notified to the network operator by the installer too.
What each piece costs in VAT and grants
The three pieces are taxed differently, which matters most for the Carshalton South and Clockhouse semis and detached houses most likely to fit all three at once. Under HMRC’s VAT Notice 708/6, residential solar panels and batteries are zero-rated until 31 March 2027, with 5% from 1 April 2027. A home EV charger is not on the energy-saving materials list, so it carries 20%. A quote that combines all three should show the VAT on each line.
Grants depend on your home. Owner-occupiers of houses get no OZEV chargepoint grant; that scheme closed in April 2022. Renters and people who own and live in flats can get 75% of the purchase and installation cost, up to £500 per socket, with private off-street or allocated parking, through an OZEV-authorised installer. On-street-only households can get up to £500 towards a chargepoint with an approved cross-pavement solution, subject to Sutton Council’s rules. Our post on who qualifies for the EV chargepoint grant has the detail.
Which Carshalton homes suit all three
Carshalton’s housing splits sharply. In Carshalton South and Clockhouse, Census 2021 puts 45.3% of households in semis and 24.1% in detached houses, with 80.7% owning their home: most can decide on all three pieces themselves. In The Wrythe, 31.1% live in terraces and 29.9% in purpose-built flats. In St Helier West, the ward covering part of the London County Council’s 1928–1936 St Helier estate, 58.3% of households live in terraced houses and 37.9% rent socially, 29.3% from the council, so a tenant needs the landlord’s written consent before a charger or a battery goes on the wall.
Flats are where the grant rules and the building rules meet, and in The Wrythe they house nearly a third of households. A flat owner with allocated parking may qualify for the £500 grant, but the cable route to the bay and any battery inside the flat usually need the freeholder’s agreement first.
June and December in SM5
PVGIS, the European Commission’s solar model, gives about 481 kWh in June and about 138 kWh in December for a 4 kWp array facing due south in Carshalton, roughly 16 kWh and 4.5 kWh a day on our arithmetic. In June a car at home in daylight can take a useful share of that. In December the panels barely cover the house, and the car and the battery both rely on overnight off-peak units. That seasonal swing is why we size a Carshalton battery to the household’s evening use, not to the car. The roof side is on our page on solar panels in Carshalton, and the neighbouring boroughs are on our south-west London solar panels hub. For the charger itself, see our home EV charger installation page.
Sources: Department for Transport and DVLA, VEH0142 licensed plug-in vehicles by local authority, 2026 Q2 (published 23 September 2026); Energy Saving Trust, Battery storage (updated 19 August 2026); HMRC, VAT Notice 708/6; GOV.UK, Changes to electric vehicle chargepoint grant schemes from 1 April 2026 (updated 7 July 2026); Electric Vehicles (Smart Charge Points) Regulations 2021; UK Power Networks, licence boundaries open data and fuse-upgrade guidance; Ofgem, energy price cap (October to December 2026); Energy Networks Association, EREC G98 Issue 2 (10 March 2025); ONS Census 2021, TS044 and TS054 for Sutton wards E05013757, E05013769 and E05013762 (Nomis, read 14 September 2026); Wikipedia, St Helier, London; PVGIS 5.3, European Commission Joint Research Centre (PVGIS-SARAH3 2005–2023, run 15 October 2026).