Assumptions for calculating the charging cost savings

The following parameters can be set:

The annual mileage can be varied in these steps: 10,000 km, 15,000 km, 20,000 km.
The costs for the electricity tariff can be varied in these steps: 30 Ct./kWh, 32 Ct./kWh, 36 Ct./kWh.
A PV system with 10kWp can be selected as an option.
For electricity consumption, only the household's electricity consumption is entered and can be varied in these steps: 2,500 kWh, 3,500 kWh, 4,500 kWh.

Three different charging profiles:

A) “At night”: The electric car can be charged after the average daily use from 5 pm in the evening until 8 am in the morning.

B) “Half-day”: The electric car can be charged after the average daily use in the afternoon from 1 p.m. until 8 a.m.

C) “All-day”: The electric car is used exclusively in the morning and can be charged from 9 a.m. until 8 a.m. the following day.

The charging profiles that can be selected here are greatly simplified.

The following simplified assumptions were made:

The charging processes are market price-optimized on the basis of a dynamic electricity tariff.
The day-ahead prices from 2024 based on an HPFC (Hourly Price Forward Curve) were used for the calculation.
The proportion of charging processes at home is 80%, i.e. 20% of charging processes are carried out in public spaces, for example at fast chargers.
As grid charges fluctuate locally, 19 cents/kWh of the Berlin grid were assumed.
The feed-in tariff for solar power is 8.2 cents/kWh.
The maximum charging capacity of the wallbox is 11kW.
The charging efficiency depends on the charging power and averages 94.5%.
The power consumption of the electric car is based on an ID.4 Pro 210 kW (286 PS) 77 kWh 1-speed automatic and is 16 kWh/100km according to the WLTP standard, regardless of the time of year.
The vehicle battery has a size of 77 kWh and is based on an ID.4 Pro 210 kW (286 PS) 77 kWh 1-speed automatic.
The target SOC of the vehicle battery is 80%, i.e. the vehicle battery is always charged to this value.
The discharge capacity of the home storage system depends on the battery capacity and is 0.5 kilowatts per kilowatt hour of battery capacity, i.e. 5 kW.
Charging takes place from a PV surplus of 1.4 kW until the battery of the electric car is 100% full.
No distinction is made between working days and weekends in the daily use of the vehicles. The calculation assumes that the solar power currently generated is always used first for the household. Surplus solar power flows first into the home storage system, then into the electric car and the remainder into the electricity grid. When the home storage system is discharged, household consumption is served first and, if there is still residual power, the electric car is charged.
The PV system is a south-facing system with an optimum inclination at the Neckarsulm site.
Solar power yield: around 1,200 kilowatt hours per kilowatt of photovoltaic output per year.

Calculate how much you can save today

Reduce your electricity costs today – with smart solutions from Elli. Only want to use energy when it’s at its cheapest? No problem. Elli’s intelligent solutions automatically optimize charging times so that power is only drawn when electricity rates are at their lowest – making a valuable contribution to the energy transition in the process.

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Can you really save money while using electricity?

Did you know that the price of electricity is constantly fluctuating? It is heavily influenced by factors such as the weather or the time of day. This means that how much you pay for your electricity depends on exactly when you start charging your EV.

With Elli, you can make the most of this savings potential. Intelligent functions allow you to charge your vehicle when the electricity is cheapest for you – which is pretty clever!

Elli has the perfect solution for everyone. Elli does that.

An overview of what we have to offer:


The new Elli Charger 2 intelligently regulates the supply to your EV with up to 22 kW of charging power.

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The latest generation
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Dynamic electricity tariff

With the Volkswagen Naturstrom Flex tariff, your electricity consumption is billed by the hour using your smart meter at the rate applicable when the electricity is consumed.

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Full control via app

Our smart charging app ensures that the EV, vehicle app, charger, and the flexible electricity tariff interact seamlessly with one another – meaning you always know what’s going on. Plus, your identified usage profile makes sure you avoid any unwanted surprises – your EV is always ready when you need it. All while you charge as cheaply as possible.

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Smart control

Sophisticated forecast calculations in the smart control software help us to plan the best and most precise way to save you money when charging your EV before you plug it in. This means that your consumption is always optimized in the same way. And what’s more, you also help to protect the environment without breaking a sweat.

You will mainly use electricity from the grid when the price is low, which is usually the case when there is an oversupply of renewable energies. If you have your own solar panels, give preference to using the electricity they produce to charge your EV, as this is especially self-sufficient and sustainable.

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Calculate how smart charging can save you here

The results are based on simulation calculations under simplified assumptions, whereby the charging processes are optimized on the basis of a dynamic electricity tariff at market prices.In practice, the values can also deviate significantly from this. More detailed information on the calculation basis and the calculation method can be found here.

What next?

You will find everything you need to know on our products page – where you can also place your order.


Support for your Elli Charger

Send your support request to Elli Customer Support

toll-free, Monday to Sunday, 6 am to 10 pm

00800 - 3554 1111*

* Toll-free number. Calls from cell phones may incur charges depending on your provider. If your provider does not support this number, please ask them to enable “00800” numbers. Costs will depend on the respective tariff of your provider. Calls from abroad may incur roaming charges.