BrightGridAdding an EV to a home with solar panels changes the energy equation. An electric car creates a large, flexible electricity load that can potentially absorb surplus solar generation. Add a battery and the home becomes a more flexible energy system, with several ways to decide where electricity should go.
How solar, battery and EV charging work together
Solar panels generate electricity during the day. A battery can store some of the surplus. An EV charger can send electricity directly to the car. The home's normal appliances use electricity as required.
| Component | Main role |
|---|---|
| Solar panels | Generate electricity |
| Home battery | Store electricity for later |
| EV charger | Supply electricity to the vehicle |
| Smart controls | Manage when flexible loads operate |
Can you charge an EV directly from solar?
Yes. A compatible smart charger can be configured to use surplus solar electricity. The amount of solar available changes throughout the day, so the charging strategy may either prioritise solar-only charging or combine solar generation with grid electricity.
Solar-only EV charging
Solar-only charging attempts to use surplus solar generation without importing electricity from the grid. This can be attractive when the car is parked at home during daylight hours, although charging speed may vary with cloud cover and solar output.
Should the battery charge the EV?
Not necessarily. Routing solar through a home battery and then into an EV introduces additional conversion losses. In many circumstances, using surplus solar directly in the EV can be more efficient than storing it in the home battery first.
What about overnight EV charging?
If the car is normally away during the day, a smart EV tariff may make overnight charging attractive. The exact financial outcome depends on the tariff and charging requirements.
Do you need load balancing?
A 7kW EV charger can represent a substantial electrical load. Load management can reduce charging power temporarily when other large appliances are operating, helping manage the home's available electrical capacity.
The cheapest electricity is not always the best strategy
A good energy-management system considers solar generation, battery state of charge, EV requirements, household demand and tariff prices together.
What does an ideal solar + battery + EV setup look like?
- Solar panels sized around household and EV demand.
- Battery storage sized around evening and overnight consumption.
- A smart EV charger.
- Appropriate electrical protection.
- Load management where required.
- A tariff that supports the household's charging pattern.
- Monitoring so energy flows can be reviewed.
Design your complete home energy system
Combine solar, battery storage and EV charging into one system designed around your electricity use.
Check Your SavingsFrequently asked questions
Can I charge my electric car from solar panels?
Yes. A compatible EV charger can use surplus solar electricity to charge the vehicle when solar generation is available.
Should solar charge my EV or home battery first?
It depends on your priorities and tariff. Directly charging an EV from surplus solar can avoid some storage losses, while a battery provides flexibility when the car is not available.
Do I need a battery if I have an EV and solar?
Not necessarily. An EV itself can absorb significant surplus solar electricity, particularly if it is parked at home during the day. A battery adds additional flexibility.
Can a 7kW EV charger overload my house?
A proper installation assesses the property's electrical capacity. Load management may be used where appropriate to reduce charger output when other high-demand appliances are operating.
Sarah Kimani
Systems Designer at BrightGrid Energy
