Vehicle-to-Grid (V2G)

In order to avoid that solar and wind energy have to be curtailed in times of overproduction, electric cars can be used as temporary storage: As soon as they are connected to the power grid via a charging station, the electricity can be charged into the battery. Using a correspondingly enabled charging station, the electricity is fed back into the grid in times of low energy production. This is also called bi-directional charging.

With vehicle-to-grid technology, renewable energies can be used efficiently. The V2G simulator developed by LADE shows the potential behind V2G and what the power grid of the future could look like.

Charging infrastructure

Charging infrastructure is the generic term for charging points and charging systems including the operational management tools available for EV charging. Depending on the access, a distinction is made between public, semi-public and private charging infrastructure.

Public charging infrastructure includes charging points on public roads or in areas restricted to user groups (parking lots for suppliers, police, fire brigade …). in Germany, this can also include charging points that are not available around the clock, but at least twelve hours on weekdays (Monday to Saturday).

Semi-public charging refers to charging points that are available to the public but are located on private property. These are, for example, charging points in parking garages, hotels and supermarkets.

Private charging infrastructure includes charging points at private parking spaces (carport, garage…).

Charging point

A charging point is an electrical device with all safety-relevant equipment required to charge electric vehicles. Through a charging point, the vehicle is connected to the supply network. Only one vehicle can be charged at a charging point at the same time. A charging park, on the other hand, can have several charging points in order to charge several vehicles at the same time.

Charging pole

A charging pole provides at least one charging point. Thanks to a robust housing, it is suitable for outdoor use. It is mounted on the ground. Some manufacturers offer the option to mount wallboxes on steles. Charging poles allow electric vehicles to be charged.

Wallbox / LADEbox

A wallbox is a charging point. It is suitable for indoor installation (garage, multi-storey car park, etc.). Wallboxes are usually attached to the wall. They are mainly used in private areas to charge electric vehicles.

Charging station (for electric vehicles)

A charging station is a technical system that supplies battery electric vehicles with energy. This usually happens via a plug connection (conductive charging). But it can also be inductive. The energy is then transferred wirelessly. A charging station can comprise one or more charging poles or wall boxes. People also use the term charging point.

Alternating current

Alternating current is electrical current that periodically changes its flow direction. Alternating current is abbreviated to AC.

The German and European power grids provide alternating current. In order to charge electric cars, this electricity has to be converted into direct current. With AC charging, this happens by the charger in the e-vehicle, and with DC charging it happens by the charging station itself.

AC charging (regular charging)

How does AC charging work and what are the advantages?

AC charging stations supply the electric car with alternating current (AC). An on-board charger in the vehicle converts the alternating current into the direct current (DC) required for the battery.

The charging capacity of most on-board chargers is between 3.7 and 22 kW. Theoretically, up to 44 kW are possible.

The charging power depends, among other things, on the vehicle model, the available power supply, the cabling and the construction of the charging point.

AC charging is particularly useful for longer idle times of 20 minutes or more: at home overnight, during working hours, when doing weekly shopping, etc.

AC charging is very beneficial to the grid, as users expect a certain length of stay, anyways, which gives more leeway to control the charging capacity.