Bidirectional charging: the 6 biggest questions and answers

Some people believe that all you need for a modern electric car is a new home charger and then you’re ready to start bidirectional charging.

In theory, thanks to bidirectional charging, some vehicles can also feed electricity back to households, buildings, or the power grid—thus becoming flexible energy sources. At the moment, however, only certain models and special charging stations support this feature. This is because, in order to feed power back into the grid, the battery’s direct current (DC) must be converted into alternating current (AC) for the grid. The electric car thus becomes an energy storage device. Not all electric cars can do this yet.

The good news: There are more and more bidirectional-capable vehicles—because word has already spread throughout the energy and automotive industries that this technology is the future.

By now, all major German automakers either have bidirectional-capable vehicles in their lineup or have announced such models. Click here, for an overview of cars that are capable of bidirectional charging.

There are already several EV home chargers on the market that support bidirectional charging, including ChargeLine BiDi from The Mobility Houe Advantages. Its benefits:

• Designed for every use case: V2G as well as V2H
• Manufacturer-independent and future-proof
• Easy installation

Additional models from other manufacturers have been announced or are currently being tested in pilot projects. So far, most providers rely on DC technology.

The short answer is: No, it does not. It might sound logical that frequent charging and discharging causes more wear and tear on the battery, but the reality is more nuanced.

Studies have shown that smart charging and manufacturer battery warranties keep the impact on the battery's lifetime minimal. In fact, often the battery stays healthy longer than the car around it.

A study by RWTH Aachen University on battery aging shows that after 10 years of use, the additional aging caused by V2G is between 1.7* and 5.8 percentage points, all while offering EV drivers up to €600 of value each year.

You can read all findings of the study in our white paper “Bidirectional charging and its impact on the service life of electric car batteries"

Many people think that feeding electricity back from the car into the grid (Vehicle-to-Grid) is not permitted by law, at least not in Germany. In reality, it was never prohibited, but until recently, it was simply extremely complex from a regulatory perspective and commercially unviable. Similarly, many other EU countries lacked clear rules for vehicles feeding power back into the grid, such as regulations concerning remuneration, billing, or grid security

However, since early 2026, bidirectional charging has finally become commercially viable in Germany. Through a legislative amendment, lawmakers have removed the biggest hurdle for Vehicle-to-Grid: double grid fees have been abolished. Previously, temporarily storing electricity in EV batteries and subsequently feeding it back into the grid incurred double grid fees as well as electricity taxes.

Furthermore, the Federal Network Agency’s so-called 'MiSpeL' consultation will ensure that feeding power back into the grid no longer requires a second smart meter or complicated processes.

The groundwork for scaling V2G has thus been laid. Now, it simply needs to be put into practice.

Vehicle-to-Home (V2H) and Vehicle-to-Building (V2B), however, are already legally possible, however, as they do not affect the public grid. Countries such as the Netherlands, Denmark, and the UK are considered V2G pioneers with pilot projects and simplified rules.

Although doubts about profitability are often expressed, they do not hold up to scrutiny: the savings achieved through bidirectional applications are very real. For example, V2H combined with PV systems can enable self-sufficiency rates of over 80%. When electricity prices are high (e.g., >30 cents/kWh), managing self-consumption is clearly financially worthwhile.

Moever, with dynamic electricity tariffs or grid service renumerations, V2G will become even more attractive. Initial commercial applications show that if you plug in your EV for an average of 14 hours per day and make its battery available for bidirecitional charging, you can effectively reduce your charging costs to €0. Ultimately, the exact savings depend heavily on driving profile, household load, and chosen tariff.

The opposite is true! With the right control system, electric cars can even stabilize the grid, shave peak loads, and maximize the use of renewable energies. Research and practical experience show that large electric fleets can take on many tasks that were previously reserved for conventional power plants.

For example, during periods of low wind and solar generation, connected EVs can step in as a "virtual power plant" to close supply gaps. We proved this works in a pilot project in 2018, when a Nissan Leaf was prequalified for primary frequency regulation (FCR) for the first time, acting as a large power plant in accordance with transmission system operator guidelines.

The larger the fleet, the greater the relief for the grid – and the lower the costs for grid expansion.

Not every home installation in Germany is automatically ready for V2G right out of the box. To safely feed electricity back into your home or the public grid, the following technical requirements must be met:

• A standard three-phase house connection with a minimum output of 11 kW is required to safely enable the necessary power flows.
• Depending on the age of the building, a qualified electrician must check the domestic wiring, fuses, and protection systems to prevent overloads.
• The installation of a bidirectional home charger and all accompanying components (including smart meters and Home Energy Management Systems (HEMS)) must be carried out by a certified electrical contractor.
• An intelligent Home Energy Management System (HEMS) is crucial. It acts as the brain, continuously optimizing energy flows between your EV, solar panels, and the grid.
• A stable internet connection is vital for communication between EV, home charger, smart meter, energy management system, and, if applicable, the external power grid.

In Germany, the setup must be registered with the grid operator. A smart meter is required for accurate billing.