Between the end of June 2025 and the end of June 2026, DVLA’s count of privately kept plug-in vehicles across North Hertfordshire went from 3,219 to 4,509. That is about 1,290 more privately kept plug-in vehicles in a single year, a rise of roughly 40% (our arithmetic). The count covers the whole district, Hitchin and Letchworth included, and it counts vehicles, not chargers or households. But it explains why a car now often sits in the middle of a conversation about a home battery.
This guide sets out how the three pieces, car, battery and panels, share one supply in a Hitchin home, and where the battery actually earns its place. For the battery in general, including where it goes and how it connects, see our page on battery storage in Hitchin.
Three pieces, three different jobs
Panels make electricity in daylight. A battery moves electricity from when it is cheap or plentiful to when it is dear or scarce, usually the early evening. A car is the biggest single load most homes will ever add, and it is usually charged overnight. Each has a different job, and it is tempting, but wrong, to size the battery for the car. A home battery is sized to the house’s evening use; the Energy Saving Trust says there is no exact formula and puts a typical home system at 10 kWh, which is small next to the 60 kWh charge used in the example below.
What a Hitchin roof can give the car
PVGIS 5.3 estimates a 4 kWp array facing due south at 35° in Hitchin makes about 478 kWh in June and about 136 kWh in December. That is roughly 15.9 kWh a day in June and 4.4 kWh a day in December (our arithmetic). In June, if the car is at home during the day, a good share of surplus solar can go straight into it, no battery needed. In December, the whole month’s output is about 136 kWh, a little more than two 60 kWh charges (our arithmetic), and the house uses most of it as it is made. Winter car charging in Hitchin comes from the grid, whatever is on the roof.
That is why the tariff matters more than the roof for a driver. At the Ofgem price-cap unit rate for October to December 2026, 26.32p per kWh on Direct Debit, a 60 kWh charge costs about £15.79 (our arithmetic on the average capped rate). Off-peak EV tariffs price overnight units well below that. A battery on the same kind of tariff can charge overnight too and carry the cheaper electricity into the evening for the house.
The supply has to carry all of it
A 7.4 kW home charger draws 32 A continuously. Most homes have a 60 A, 80 A or 100 A main fuse, and a charger with load management, a current sensor on the incoming supply, usually avoids a supply upgrade by easing off when the house is busy. UK Power Networks says it can upgrade a main fuse from 30 or 60 A to 80 or 100 A, and that where an installer has applied to connect the device an upgrade may not be needed. A looped supply shared with a neighbour has to be re-planned with both households. Every new home chargepoint sold in Great Britain has had to be smart since 30 June 2022, and the installer notifies the network of each one.
The battery and panels go through the same network. Hitchin’s town centre sits in UK Power Networks’ Eastern Power Networks licence area. A system up to 16 A per phase (3.68 kW) is notified under G98; anything larger needs a G99 approval before work starts. Planning the charger, battery and panels together means one design for one supply, rather than three separate jobs that each assume the fuse is theirs. Our guide to whether your fuse will take a 7 kW EV charger goes further.
VAT and grants differ for each piece
Residential solar panels and batteries carry 0% VAT until 31 March 2027, reverting to 5% from 1 April 2027. A home EV charger is not on the energy-saving-materials list, so its installation is standard-rated at 20%. For grants, the OZEV scheme for owner-occupiers of houses closed in April 2022; renters and people who own and live in flats can claim 75% of the cost, up to £500 per socket, with private off-street or allocated parking. North Hertfordshire’s £1.5 million Warm Homes: Local Grant allocation covers privately owned homes at EPC D to G that meet an income or other route, and the national scheme funds a battery only alongside solar PV.
How it fits in a Hitchin semi
Semis are the largest group of homes in Hitchin’s built-up area, 33.4% of households at Census 2021, with detached houses at 17.7%. Where a house has off-street parking and a garage or utility room, the battery and inverter usually sit near the consumer unit and the charger goes on an outside wall close to where the car parks, keeping both cable runs short. In the Hitchin Conservation Area, whose Article 4 direction of 9 October 2012 covers several changes fronting a highway, ask North Herts Council before fixing a charger or any unit to a street-facing wall. The 29.1% of households in flats or maisonettes start with the freeholder.
In a power cut
A standard grid-tied battery shuts down with the grid, and the charger stops too. Backup designed in at the start can keep chosen circuits running, but it is sized for the fridge and lights, not the car. We are a NAPIT member (73495), MCS-certified for solar PV and battery storage through NAPIT. The roof is covered on our page for solar panels in Hitchin, the county on our Hertfordshire solar page, and sizing in our guide on what size home battery you need.
Sources: DfT and DVLA, VEH0142 licensed plug-in vehicles, private keepers, North Hertfordshire, 2026 Q2 and 2025 Q2 (published 23 September 2026); European Commission JRC, PVGIS 5.3, PVGIS-SARAH3 2005–2023 (run 15 October 2026); Ofgem, energy price cap October to December 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) and Warm Homes: Local Grant successful local authorities (updated 2 July 2026); Electric Vehicles (Smart Charge Points) Regulations 2021; UK Power Networks, fuse upgrades and Open Data licence boundaries; Energy Networks Association, EREC G98 Issue 2; ONS, Towns and cities, characteristics of built-up areas: Census 2021 (table 5c); North Herts Council, About conservation areas, Article 4 directions (updated 4 August 2026).