Bidirectional charging stations for your electric car

In bidirectional charging, the vehicle battery is used as an intermediate storage of electrical energy (e.g. to store surplus solar power). In contrast to monodirectional charging, which is still common today, a bidirectional charging station can be used to feed electrical power and energy back into the building (V2H/V2B) or the electrical supply network (V2G) as required.

In principle, bidirectional charging is equivalent to the operation of stationary batteries. If the charging infrastructure complies with the VSE recommendation on grid connections for energy generation systems (NA-EEA) and the technical standards for electrical safety and electromagnetic compatibility, it can be authorised when registering with the distribution grid operator.

From 1 January 2022, bidirectional charging stations can be registered regularly with an updated technical connection application (TAG).

The following vehicles are enabled for bidirectional charging as of February 2024:

• Honda: Honda e > read more
• Nissan: Leaf (from 2014), Evalia and e-NV 200
• Mitsubishi: i-MiEV, Outlander and Eclipse Cross > read more
• Peugeot iOn and Citroën C-Zero
• VW: ID.3, ID.4, ID. Buzz and ID.7

Listed are all vehicles that allow vehicle-to-home via a suitable charging station. Vehicle-to-load, such as the Hyundai Ioniq 5, must be considered separately. Here, you can only draw a limited amount of power via an onboard plug (single-phase, up to 3.6 kW), but you cannot supply a house with electricity.

Further information: In principle, all Japanese electric vehicles can charge bidirectionally because this is mandated by the Japanese government. So far, bidirectional charging is primarily possible for vehicles with CHAdeMO plugs. The Honda e is an exception, it can do bidirectional charging via the CCS plug. Bi-directional charging requires approval from the vehicle manufacturer and certification of the charging station for the specific vehicle type.

Several vehicle manufacturers have announced that their vehicles will be enabled for bidirectional charging in the near future. In general, the introduction of an international standard ISO 15118-2020 is expected by 2025, which will also regulate bidirectional charging with CCS charging plugs in a binding manner.

Advantages: Optimisation of energy use and support for the energy transition. The self-consumption of the PV system can be significantly increased, thereby reducing electricity costs. Renewable energy is stored and therefore utilised optimally and efficiently. The idle times (usually an average of 23 hours/day) of the e-vehicles can be utilised. The car has multiple uses and is not just a means of transport. The power grid is relieved. Possible price fluctuations in electricity costs can be balanced out.

Disadvantages: The regulatory requirements are not yet fully in place. At present, the electricity from the car battery can only be used for personal consumption. The price of the bidirectional charging station is higher compared to a monodirectional wallbox. However, the cost of a stationary battery should be taken into account when making a comparison. Only a few vehicles are currently approved by the vehicle manufacturers for bidirectional charging

Bidirectional charging is generally permitted in Switzerland. Two models of bidirectional DC charging stations are currently available for purchase. The two-way digital and two-way10 models from sun2wheel are the only certified wallboxes for Switzerland. Sun2wheel has been selling these wallboxes since 2021 and can draw on corresponding experience. > go to products