Everything you need to know about bi-directional charging and your Blue Current charge point
If you don't immediately need the car for transport, you can just as well use the energy in your battery for something else, such as for the washing machine or charging your e-bike. The energy in your battery is then used for something other than the car itself, which means that the energy can flow in both directions - away from the car and towards the car. A term you will often hear for this is bi-directional charging and V2X.
V2X is often explained as Vehicle-to-everything, but Vehicle-to-anything is actually a more appropriate name. It is the umbrella under which all other Vehicle-to-something concepts fall. If you can replace the X with just one other letter, as a car manufacturer you can already say that you support V2X. So pay close attention to which type of V2X is supported, on the website ev-database.org you will find for every type of car whether this means V2L, V2H or V2G.
What types are there?
The batteries of all electric cars together form one gigantic storage that can be used in times of energy shortage, when the sun is not shining and the wind is not blowing. However, the fact that this is currently only a vision and not a reality does not mean that we are not working hard on the road and bi-directional charging is an important milestone on this road. There are different iterations within bi-directional charging, the Vehicle-to-X. There is V2L, V2H, V2B and V2G.
Vehicle-to-load (V2L) means nothing more than that there is a 'normal' socket in the car to, for example, charge your e-bike or connect the vacuum cleaner. With Vehicle-to-home (V2H) or Vehicle-to-building (V2B), the car can actually supply energy back to the house via a charge point, but only if the house is not connected to the public grid. In theory, this could come in handy, for example, in the event of a power failure, where the house is or will be disconnected from the public grid. In the Netherlands, however, this function will hardly be used. If the car supports Vehicle-to-grid (V2G), it can also supply energy to the house via the charge point, but now also if the house is connected to the public grid. This can be used, for example, to feed back sustainable electricity generated during the day at times of energy shortage. On a large scale, this could in time provide a solution to challenges in the national energy supply and the use of more sustainable energy sources.
V2G in practice
The car is compatible with V2G, so why can't you return? This is because the car does not support V2G at AC (alternating current) charge points.
With a 'normal' (AC) charge point, such as you have at home, at companies or in the town centre, the car itself converts alternating current to direct current. The technique for doing this becomes more complex as more power has to be converted, which is why the speed at which you can charge at such a charge point is limited. With a supercharger or fast charger (DC), the conversion of current takes place before it enters the car- in a small container that you can see next to the superchargers.
The technique
You cannot simply feed energy back into the grid with every car and at every charge point, because there are three separate technical challenges that car manufacturers must overcome for the implementation of Vehicle-to-grid (V2G).
The first challenge is power conversion. When feeding back, direct current must be converted back to alternating current, but the technique for doing this is different for one direction than for the other. For bi-directional charging, the car requires additional electronics.
The second challenge is communication. The communication between the car and the charging station is standardised, but very limited. A new protocol called ISO 15118 enables the car and charge point to exchange more complex information, such as the state of the battery, identification of the car and also information about the return of energy. To be able to use this communication, additional electronics and software are required.
The third challenge is adaptation to the grid. When returning power, the car has to adapt its power to the grid. Similarly, the car must properly assess how to feed back the power, and if it does not do so, it will disrupt the grid.
Depending on which of these technical challenges are solved and implemented, the car can be Vehicle-to-load (V2L), Vehicle-to-home/building (V2H, V2B) or Vehicle-to-grid (V2G). There is even a last variant, in which the car does not support any V2X version, but other possibilities of the more complex communication between car and charge point can already be used.
So when purchasing a car, pay close attention to what the options are for you. At Blue Current, we remain committed to all smart charging solutions, including Vehicle-to-grid (V2G), to accelerate the energy transition.