Plug-in cars are no longer unusual on Barnet driveways. DVLA records 12,097 privately kept plug-in vehicles across Barnet borough at the end of June 2026, up from 10,089 a year earlier, an extra 2,008 cars, or about 20% (our arithmetic on the Department for Transport’s table). We use the privately kept figure because the borough total of 15,749 includes company-registered cars. For a household weighing solar panels in Barnet with an electric car on the drive, the obvious question is whether the roof can fuel the car.
The short answer is: some of the time, and far more in June than in December. This guide puts numbers on that for a High Barnet roof, then covers the charger, the main fuse and where a battery does and does not help. The figures are for the borough or for a single PVGIS point; your own roof and driving set the real answer.
What a Barnet roof makes across the year
PVGIS 5.3, the European Commission’s solar model, puts a 4 kWp array facing due south at 35° in High Barnet at about 3,959 kWh a year, with 14% system losses on the 2005–2023 satellite record. The monthly split is the point for an EV driver: about 477 kWh in June and 483 kWh in July, against about 157 kWh in January and 139 kWh in December. Per day, that is roughly 15.9 kWh in June and 4.5 kWh in December (our arithmetic).
To put that next to a car: putting 60 kWh into a battery takes the whole output of that High Barnet roof for about four June days, or about thirteen December days, before the house uses any of it (our arithmetic). A due-south, unshaded roof is the best case; an east or west slope, or a tall tree on an Arkley plot, pulls both figures down.
Daylight is the catch
Solar charging only works when the car is plugged in while the sun is up. A Barnet household with someone at home during the day, or a second car that sits on the drive, can use a smart charger to send surplus solar into the car. A commuter whose car leaves at eight and returns at six will do most charging overnight whatever is on the roof. In that case the panels earn their keep by cutting what the house buys in daylight, and the car runs on grid electricity. At the October to December 2026 price-cap unit rate of 26.32p per kWh, 60 kWh would cost about £15.79 (our arithmetic on the average capped rate); off-peak EV tariffs price overnight units well below that.
Where Barnet households charge
Housing decides who can fit a charger at all. In High Barnet ward, 23.7% of households live in detached houses and 24.7% in semis, and 67.6% own their home, so many of those households control both the roof and the parking. Barnet Vale, next door, is different: 37.2% of its households live in purpose-built flats, where parking and roof space belong to a freeholder or management company. In Underhill, 24.0% of households rent socially, which puts both decisions with a landlord.
The government’s OZEV grants follow the same lines. Owner-occupiers of houses get no grant. Renters and people who own and live in flats can get 75% of the cost, up to £500 per socket, with private off-street or allocated parking; households with on-street parking only may get up to £500 towards a chargepoint with an approved cross-pavement solution, subject to the council’s rules. Our guide to who qualifies for the EV chargepoint grant goes through each route.
The fuse in a Barnet semi
A 7.4 kW charger draws 32 A continuously, and most homes have a 60 A, 80 A or 100 A main fuse. Load management, a sensor on the incoming supply that turns charging down when the house is busy, usually avoids an upgrade. Barnet sits in UK Power Networks’ Eastern licence area, and the installer notifies UK Power Networks of every new chargepoint. UK Power Networks says it can upgrade a main fuse from 30 or 60 A to 80 or 100 A. In East Barnet, where semis house 36.4% of households, it is worth asking at the survey whether your supply is looped, meaning shared with a neighbour; a looped supply has to be re-planned with both households and may carry a charge. Our guide to whether your fuse will take a 7 kW charger covers the checks.
Where a battery fits, and where it does not
A home battery is not a car charger. The Energy Saving Trust puts a 5 kWh system at around £4,600 and says a typical home system might be 10 kWh, which is a fraction of a car’s battery. In practice most EV owners charge the car directly and let the home battery carry daytime solar into the house’s evening. Our page on battery storage in Barnet covers sizing for that job. One more point: a standard grid-tied battery shuts down in a power cut unless backup is designed in, so it is not a reason on its own to buy one.
VAT and the order of work
The VAT rules treat the three devices differently. Residential solar panels and batteries are zero-rated until 31 March 2027 and 5% from 1 April 2027; a home EV charger is not on HMRC’s energy-saving materials list and carries 20%. Every new home chargepoint sold in Great Britain has had to be smart since 30 June 2022. If panels, a battery and a charger are all on a Barnet household’s list, one survey that looks at the roof, the consumer unit and the main fuse together avoids doing the supply work twice.
Next step
Barnet borough sits within our solar panels in North London coverage, and green belt, which covers 46.4% of the Chipping Barnet constituency, does not by itself remove a house’s roof-mounted rights. If the survey shows your roof or your driving pattern would not make solar worth it for the car, we will say so. You can ask for one through our contact page.
Sources: DfT and DVLA, VEH0142 licensed plug-in vehicles by local authority, Barnet, 2026 Q2 and 2025 Q2 (published 23 September 2026); PVGIS 5.3, European Commission Joint Research Centre (PVGIS-SARAH3 2005–2023; 4 kWp, 35°, due south, 14% losses; High Barnet run 15 October 2026); Ofgem, energy price cap unit rate October to December 2026; ONS Census 2021, TS044 and TS054, High Barnet, Barnet Vale and Underhill wards, via Nomis; 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 EV charging guidance; Energy Saving Trust, Battery storage (updated 19 August 2026); HMRC, VAT Notice 708/6; MHCLG, green belt statistics 2024-25. Daily, per-charge and percentage figures are our arithmetic.