Why charging at home changes everything
Take the worked example below: at €0.20 per kWh at home against €0.45 in public, a driver covering 5,000 km a month pays €180 at home and €405 in public. That is €0.036 per km against €0.081, a €225 gap every month, before any other cost is counted. This calculator puts your own two prices side by side the same way, per km and per month.
Wallbox payback
On that same example, a €1,200 wallbox pays for itself in 5.3 months — €1,200 divided by the €225 monthly saving. Drive fewer km, or pay prices closer together, and the payback stretches; charge only in public, and there is no saving for a wallbox to pay back at all.
What's the best car for TVDE — electric or combustion?
There's no single answer — it depends on how much you drive and where you charge. For drivers doing many km a month with somewhere to charge at home or at work, an EV with good real-world range (not just the advertised range) usually wins clearly on cost per km and maintenance. For low-mileage drivers, or those relying entirely on pricier public chargers, a hybrid or an efficient diesel can still make more sense, at least for now.
Worked example: 5,000 km a month
Take a driver doing 5,000 km a month in a car that uses 18 kWh per 100 km, paying €0.20 per kWh at home and €0.45 per kWh at public chargers, with a wallbox that cost €1,200. The calculator works it out like this: monthly energy use is 18 ÷ 100 × 5,000 = 900 kWh. Charging at home costs 900 × €0.20 = €180 a month; the same energy in public costs 900 × €0.45 = €405. The saving from charging at home is €405 − €180 = €225 a month. Per km, home charging costs 18 ÷ 100 × €0.20 = €0.036, against 18 ÷ 100 × €0.45 = €0.081 in public. The wallbox pays for itself in €1,200 ÷ €225 = 5.3 months — after that point, the €225 a month is pure saving against public charging, month after month, for as long as the driver keeps the same pattern.
| At home | Public charger | |
|---|---|---|
| Energy used (per month) | 900 kWh | 900 kWh |
| Cost per km | €0.036 | €0.081 |
| Monthly cost | €180 | €405 |
| Saving vs public | €225 | — |
| Wallbox payback (€1,200) | 5.3 months | — |
The public-only driver
The same math looks very different without home charging. A driver doing 3,000 km a month at 17 kWh per 100 km, charging only in public at €0.50 per kWh, uses 17 ÷ 100 × 3,000 = 510 kWh and pays 510 × €0.50 = €255 a month, or €0.085 per km. There is no saving for a wallbox to pay back, so the calculator shows no payback in that case — correctly, because the wallbox only earns its cost back from the gap between two prices, and a driver who never charges at home has no gap. For this driver, the lever is not equipment but price: finding cheaper public charging, or any regular access to a domestic socket, even part of the time, changes the monthly figure more than any other single factor.
What moves the number most
Three inputs drive the result, and they do not matter equally. The price gap between home and public charging matters most: on the 5,000 km example, if the home price rose from €0.20 to €0.30 per kWh, home charging would cost 900 × €0.30 = €270, the saving would fall to €405 − €270 = €135 a month, and the wallbox payback would stretch from 5.3 to €1,200 ÷ €135 = 8.9 months. Consumption comes second: at 22 kWh per 100 km instead of 18, the same 5,000 km needs 22 ÷ 100 × 5,000 = 1,100 kWh, costing 1,100 × €0.20 = €220 at home and 1,100 × €0.45 = €495 in public, a saving of €275 a month. Kilometres come third in one sense — more km means more total saving — but they do not change the per-km cost at all, which is why two drivers with the same car and prices but different mileage get the same €0.036 and €0.081 per km and very different monthly totals. The practical order for a driver trying to cut charging costs is therefore: secure the cheapest charging location first, then watch real consumption, then let mileage do what it does. And because cost per km feeds straight into trip profit, it is worth carrying the result over to the Trip Calculator, which judges a single trip by its € per km, and to the Monthly Income page, where charging sits alongside fuel, commissions and taxes in the full monthly picture. The Fuel Cost page runs the same comparison for a petrol or diesel car, so a driver weighing electric against combustion can compare like with like.
Frequently asked questions
Is an electric car really worth it for TVDE?
For drivers doing many km a month who can charge at home, usually yes — cost per km drops significantly versus petrol or diesel, and there's less maintenance (no oil, no clutch, less brake wear). The math changes if you depend solely on public chargers, which are much pricier, or if you do few km — then the higher upfront cost of the car takes longer to pay off. It's worth running your own numbers above rather than trusting a general rule.
What consumption figure should I use?
Start from 16–20 kWh/100 km for city TVDE use, then test the ends of that range. Over 5,000 km a month at €0.20 per kWh at home, 16 kWh/100 km means 800 kWh and €160; 20 kWh/100 km means 1,000 kWh and €200. The same two figures in public at €0.45 per kWh cost €360 and €450. Your own figure beats either end: divide the kWh you actually charged over a month by the km you drove, and enter that.
Does the wallbox always pay for itself?
No. The payback is the wallbox cost divided by the monthly saving against public charging, so it only works when there is a saving. If you charge mostly at home at a low domestic rate, the saving is large and the payback is measured in months, as in the example above. If you charge almost entirely in public, the saving is close to zero and the wallbox never pays back — the calculator shows no payback in that case. It also only makes sense if you keep the car and the charging setup long enough to pass the payback point.
Why is my real consumption higher than the advertised figure?
City TVDE driving means constant stopping and starting, short trips, and heating or air conditioning running for much of the shift, all of which push consumption above the advertised figure. That is why this page suggests 16–20 kWh per 100 km for city use rather than the brochure number. The most accurate figure is your own: divide the kWh you actually charged over a month by the km you drove, and use that in the calculator.
Is home charging always cheaper than public charging?
Only when your home price per kWh is lower than the public price you would otherwise pay. The saving is simply the public cost minus the home cost, so if a cheap public subscription ever undercut your domestic rate, the math would flip and public charging would win. That rarely happens in practice, because domestic rates are usually well below public charger prices, but the calculator compares your two actual prices rather than assuming home always wins — which is why entering both prices honestly matters more than any rule of thumb.