The short answer

Solar can contribute to home EV charging when generation and charging overlap. A suitable charger can respond to surplus generation, but the available power and the car’s charging requirements still matter.

Start with your driving energy

For an illustrative week, 200 miles at 0.25 kWh per mile uses 50 kWh in the vehicle. If charging efficiency is assumed to be 90%, the electricity supplied to charging is about 50 ÷ 0.90 = 55.6 kWh.

Use your own vehicle’s evidence rather than this example. If that charging is already in your electricity bill, do not add it again to the household total.

Match the car’s availability to the roof

Write down the hours when the car is normally at home. Compare a weekday-away scenario with a weekend-at-home scenario rather than assuming the vehicle is always available.

Surplus is what remains after other demand at that moment. A 4 kW solar output alongside 1 kW of household use leaves about 3 kW before any other flows or constraints are considered.

Ask what the charger does when clouds pass

Manufacturer modes can differ: some top up from the grid to maintain charging, while others pause if surplus falls below their threshold. Check the actual product and car combination.

Discuss how the charger and home battery share priorities. Ask whether a boost or departure target can override a surplus-only preference.

Include the right demand in the estimate

Include EV charging in your total annual electricity use, then allocate its share to EV charging in SolarIQ. For a future EV, increase the total first. The EV field does not add consumption on top of that total. SolarIQ does not send instructions to your charger or measure your car’s actual consumption.

An installation assessment should confirm the electrical supply, charger configuration and coordination with the proposed storage system.

Before your assessment

Bring these questions with you.

  • Typical weekly mileage and measured consumption.
  • Plug-in and departure times.
  • Charging already included in household bills.
  • Solar, battery and ready-by priorities.