Bidirectional charging allows users to utilize the batteries of electric vehicles in two ways. The vehicle can not only draw power through charging processes but can also serve as a source to feed power back into the grid or directly supply consumers.
To achieve this, only a so-called rectifier is necessary. This device converts the direct current (DC) used in the vehicle into alternating current (AC). Rectifiers are either included in the electric vehicle’s on-board charger or in a corresponding wallbox.
What variants exist in bidirectional charging?
Terms like V2G, V2H, or V2L are commonly used. But what do these actually mean? These are three different and progressively complex variants of bidirectional charging.
V2L (Vehicle-to-Load) is the simplest form of bidirectional charging. It only allows external devices (such as laptops, power tools, etc.) with a standard power connection to be supplied with power from the electric vehicle’s batteries. Supplying power to a house is not possible with this function.
V2H (Vehicle-to-Home) provides the ability to supply power to one’s own house or office. A common application is, for example, supporting the power production from solar panels during the night or evening hours and filling in supply gaps.
The most advanced method is V2G (Vehicle-to-Grid). In this case, the electric car becomes part of the entire local power grid and can feed stored power back into the local power network. It functions as a mini power plant or power storage within the power grid.
This can relieve power grids, and many electric vehicles, through the use of appropriate software, can act as a temporary part of the local power grid.
Bidirectional charging in the future
Even though the current availability of electric vehicles with bidirectional charging capabilities (especially V2H and V2G) is still limited, this technology offers significant possibilities for the future. These include increased energy self-sufficiency for households, cost reductions in electricity by smoothing peak loads, or contributions to stabilizing the power grid.
More and more companies plan to integrate this function into the next generations of electric vehicles. A list of vehicles that already enable bidirectional charging can be found here.
For more information on battery technology, click here.