EV
Pairing an EV charger with solar and a battery
Charging from the roof
A smart charger can follow your solar output and use only the spare. In summer a car left on the drive by day can run mostly on your own power. In winter there is little spare, so you will still buy from the grid. Do not plan on a car being fully solar-charged all year.
If someone in the house takes Southeastern from Faversham station and the car stays on the drive on weekdays, that is a good fit for daytime charging. A car that leaves at eight and returns at six is not.
Charging by night
Take an example, labelled as one. A car that draws 2,500 kWh a year, which is our round figure, not a published one. At the 26.32p price cap that is about £660. On Intelligent Octopus Go's 7.6p night rate it is about £190 (our arithmetic, from rates read on 7 October 2026). That is a big gap, and it is the reason many car owners look at tariffs before they look at batteries. Check the tariff's eligibility rules and your car and charger first.
The day rate on those tariffs is high, so shift what you can. The tariff guide has the numbers.
Where the battery fits
A battery stores midday solar for an evening charge, and it can also fill cheaply overnight. It is a useful buffer, but a 5 kWh battery holds only a fraction of what a car needs for a long trip. It softens the evening peak. It does not replace the charger.
How big a system
A car adds a lot of demand, so a bigger array may help. Think 5 kWp rather than 3 kWp, if the roof allows. A 5 kWp system would cost more than the £5,500 to £7,500 we estimate for 4 kWp, so size it to your real mileage. Tell us your mileage and what you charge at now and we will test options in the estimator.
A sensible order of jobs
If you are buying a car, a charger and solar in the same year, do the sums in this order. Fix the tariff and charger first, because that is where the biggest saving usually sits. Then size the solar to the daytime use you will really have. Add a battery last, and only if the evening gap is still large. Doing it the other way round tends to leave you with a battery that has nothing much to do.
Fitting and grants
A home charger needs a safe supply, wall space, and sometimes a conversation with UK Power Networks, the network operator, if it adds a lot of load. Your installer tells you whether that applies. Renters and flat owners may be able to claim up to £500 towards a chargepoint, through a GOV.UK grant available until 31 March 2027. Check the current eligibility rules before you order.
The 0% VAT rule covers solar and batteries. Check the charger's VAT on its own quote. More in the VAT guide.
Questions people ask
Can solar fully charge my car?
Not in winter. In summer, with the car at home by day, a good share of the charge can come from solar.
Do I need a special charger?
A smart charger that follows solar output helps. Ask which models work with your system and your tariff.
Does 0% VAT cover the charger?
Not as far as we know. The relief names energy-saving materials such as solar and batteries. Check the charger separately.
Is there a grant for a charger?
GOV.UK lists up to £500 for renters and flat owners, available until 31 March 2027. Check it applies to you.
Want numbers for your own house? Try the estimator or ask for a free quote.
Sources
- GOV.UK: electric vehicle chargepoint grants
- Octopus Energy: Intelligent Octopus Go
- Octopus Energy: public tariff data (product list)
- Ofgem: changes to the energy price cap, 1 October to 31 December 2026
- Energy Saving Trust: battery storage
More guides
- What solar and a battery cost for a Faversham house
- Is a home battery worth it?
- What size solar and battery do I need?
- Solar only, battery only, or both?
- 0% VAT on solar and batteries, and what it means
- Planning permission and network approval in Faversham
- Cheap overnight tariffs and home batteries
- Smart Export Guarantee: real rates, October 2026
- Solar by house type in Faversham