Home and public charging mix

Short answer #

Weight each charging location by its realistic share. Add charging losses and spread charger cost over years of use; solar electricity carries at least foregone export revenue as opportunity cost.

Important variables #

• Equal holding period and mileage
• Net sale proceeds and contract cost
• Energy, maintenance and insurance
• Liquidity and finance rate

Worked example #

60% at €0.32, 25% at €0.48 and 15% at €0.69 gives €0.416 per grid kWh before subscriptions.

Break-even: What changes the result? #

Test the main driver as a cautious, central and optimistic range. Also check whether the ranking reverses at a crossover or remains robust across the range.

Common mistakes #

• Comparing monthly payments only
• Treating resale as certain
• Omitting one-offs or mileage

Sources & assumptions

• Bundesministerium der Finanzen — Steuerbefreiung für Elektroautos (2026-08-17)
• RATIOXA — Methodology and formulas (2026-08-17)