Solar · Advice
How do solar panels work with an electric car and home charger?
Short answer
Charging an EV from surplus daytime solar is one of the best uses of it, using a solar-aware charger that follows export. Most drivers still charge overnight on a cheap EV tariff in winter. If you have a battery, the charger must be wired or configured so the house battery does not drain into the car.
Last checked 24 September 2026 · 1 source
In more detail
- Solar-matched charging needs the charger to see export via a CT clamp or inverter integration; minimum charge current (~1.4 kW single-phase) means small surpluses may not be enough.
- Battery systems measure the grid with a CT or meter; if the EV charger is downstream of that point, the battery sees the car as house load and discharges into it. Installers either place the charger upstream of the measurement point or set the battery to hold during charging.
- EV tariffs like Intelligent Octopus Go give a cheap overnight window which can also charge a home battery.
- Tesla: during power cuts Powerwall can coordinate with Tesla vehicles so charging does not exceed backup capacity.
The facts, dated
- 01Traditional solar without battery backup does not work in a grid cut (Tesla UK)
manufacturer · UK · checked 24 September 2026 · Tesla
What we saw in the field
[QA review 2026-09-24] C2-11 AGREES partly; C2-10 opinion UNVERIFIABLE. | Earlier notes: Agrees with Customer 2: some chargers must be wired upstream of the battery so they don't drain it into the car; Customer 2 called the Tesla Wall Connector the weakest part (opinion).
Sources
Last checked: 24 September 2026