Short answer: Yes. A home charger can be set to use surplus solar power, and a 4 kWp south-facing system in Birmingham makes about 476 kWh in July. In December it makes about 136 kWh, so winter charging still leans on the grid. How much solar ends up in the car depends mostly on whether it's at home in daylight.
How much power a Birmingham roof makes each month
PVGIS gives a south-facing Birmingham roof about 969 kWh a year for every kWp of panels. The monthly split is what matters for a car:
| 4 kWp south-facing system | Approximate generation |
|---|---|
| December | about 136 kWh |
| March | about 340 kWh |
| June | about 464 kWh |
| July | about 476 kWh |
| September | about 364 kWh |
Not all of that goes into the car. The house uses some first, and the rest is only useful for charging if the car is plugged in while the sun is up.
Turning kWh into miles
Your car’s dashboard or app shows its efficiency in miles per kWh. Multiply that by the solar power that ends up in the car. For example, if your car does 3.5 miles per kWh and 150 kWh of solar goes into it in a summer month, that is about 525 miles of driving. Use your own car’s figure, because efficiency varies with the model, the weather and how you drive.
The car has to be home
Whether the car is at home in daylight matters most. A car that sits on the drive on sunny days can soak up a lot of spare generation. A car that leaves at 8am and comes back at 6pm will mostly charge from solar at weekends. Neither is wrong, but it changes how much of your driving the panels cover.
Solar-aware chargers
A standard charger draws power at full rate whenever the car is plugged in, whether that comes from the panels or the grid. A solar-aware charger watches how much power your home is exporting and sends the surplus to the car instead. Most offer modes such as:
- Solar only: charges only from surplus, so it stops when a cloud passes or the kettle goes on.
- Solar plus grid: tops up the surplus with some grid power so charging doesn’t stop.
- Scheduled: charges fully at a set time, usually overnight on a cheaper tariff, so the car is full by morning whatever the weather.
In winter the scheduled mode does most of the work. In summer the solar modes take over.
Where a battery fits
A home battery stores surplus solar for later, which helps if the car is out all day. But power stored in a battery and then moved to the car loses some along the way, and a home battery is small next to a car’s. Many households find it works best to let the battery cover the house in the evening and let the car charge on a cheap overnight rate when the sun can’t do it. Solar battery storage explains sizing.
Costs and the grant
Checkatrade lists EV charger installation in Birmingham at £547 to £922, with an average of £704. If you rent or own a flat, the government chargepoint grant takes 75% off, up to £500. Fitting the charger at the same time as panels or a battery saves a second visit. EV charger installation covers the process.
Bottom line
Solar can cover a real share of your driving in spring and summer, especially if the car is often at home in the day. In winter, plan on charging overnight on a cheaper tariff. A solar-aware charger does both automatically. We fit chargers and panels together, and quotes are free. Call 0121 330 1151, 9am to 7pm, 7 days.