Bi-directional charging

Bidirectional charging: The future energy storage device on wheels

The switch to renewable energy is not only important, it is even crucial if we want to achieve our climate goals by 2030. Solar, wind and hydropower could generate a large amount of sustainable electricity in the long term and partly replace power plants. But where should all the electricity be stored?

Bi-directional charging could be the solution. But what does that mean exactly? With bidirectional charging, e-cars serve as a temporary energy storage devices, which, in the event of grid fluctuations or energy peaks, return the stored energy to the power grid and make it usable again.

Such storage systems can, for example, absorb solar power on sunny days and feed it back into the grid at night or on cloudy days so that demand can be met. And that doesn't necessarily just require large energy storage devices. Electric cars can also be used as temporary storage spaces through bidirectional charging.

How does bidirectional charging work?

The principle is pretty simple. Bidirectional charging enables energy exchange in two directions. Accordingly, electricity can not only flow into the e-car battery, but also back into the wallbox. While the electric car is charging, the alternating current from the power grid is converted into direct current. If the electricity is to be fed back into the grid, it must be converted back into alternating current. The changer does this either in the wallbox or directly in the car.

What are the benefits of bidirectional charging technology?

There are two different uses for bidirectional charging:

Vehicle to Grid (V2G)

Die V2GTechnology connects electric cars to the smart grid, i.e. the intelligent power grid. If the vehicle is not used for a longer period of time, the downtime can be used to deliver the decentrally stored electricity and thus stabilize the grid at the same time. In the future, e-car drivers could even earn money or have lower energy costs by making their vehicle available as an energy storage device. This would also further reduce the cost of owning e-cars. It's convenient, isn't it?

Vehicle to Home (V2H)

As the name suggests, with the V2H-Principle, the electricity supplied is not used publicly, but privately in one's own home. In this way, personal needs can be covered, if necessary even for several days.

To understand this better, here is a calculation example:

According to the Federal Ministry of Economics and Climate Protection (BMKW), a family of four has an average daily requirement of 11 kilowatt (kW). This is what an electric car, with a battery capacity of 50 kilowatt hours, could cover for around four days.

Which cars can charge bidirectionally?

In principle, all e-cars can charge bidirectionally. To be able to use this technology, all you need is a bidirectional wallbox and an electric vehicle that supports charging in both directions. In addition to the Type 2-, and CCS-, who CHAdeMO-Plug on. CHAdeMO is the abbreviation of “charge de moVE” (charging to move) and is derived from a part of the Japanese sentence “Ocha demo ikaga desuka”.

Translated, this roughly means “How about a cup of tea?” and can be understood as an indication of possible use of time during charging. In addition, the Japanese fast-charging system enables data communication between charging infrastructure and e-cars. It sends commands as to when energy should be withdrawn or “delivered” to the car.

conclusion

With bidirectional charging, a solution was found that not only improves your own CO2 balance, but also contributes to a greener energy mix. It is only a matter of time before the new charging technology is used across the board. And Elvah will also be involved in this big step towards the future.

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