Practical guide
When is public EV charging more expensive than fuel?
The useful question is not simply whether electricity is cheaper than fuel. It is the public charging price at which your own car and fuel comparison break even.
Use a consistent measurement basis
Start with battery-side energy per 100 km. Divide by your assumed billed-energy efficiency to obtain billed energy. Use 100% where the billed quantity already matches energy entering the battery. Applying a loss factor to a wall-meter consumption reading can count losses twice.
A worked example, not a current tariff
Suppose an EV uses 18 kWh from the battery per 100 km, with 95% billed-energy efficiency for the chosen public charging arrangement. Billed energy is 18 ÷ 0.95 = 18.95 kWh per 100 km. A comparison car using 6.5 litres per 100 km at €1.70 per litre costs €11.05 per 100 km.
The energy-price break-even is €11.05 ÷ 18.95 = approximately €0.583 per kWh. At €0.60 per kWh, this public-only EV example costs approximately €11.37 per 100 km. A home/public blend changes the comparison.
Do not forget additional costs
Account for subscriptions, session fees and time-based charges without counting the same charge twice. This is an energy-cost comparison. It says nothing by itself about the overall cost of buying, insuring or maintaining either car.
Reference: ADAC charging-loss tests.