Bidirectional wallbox – V2H and V2G explained simply
Your electric car can do more than just consume electricity. With the right technology, it can also feed energy back into your home or even the grid. We'll show you how this works and how advanced the technology really is today.
How to use bidirectional charging to draw power back from your car
A bidirectional wallbox not only charges your electric car, but also draws the stored electricity back into the grid when needed. This turns your car's battery into a giant energy storage system for your home. At PVundSO, experienced electrical engineers provide honest advice on what's already possible today and what's still just a vision for the future. In this guide, we explain the technology behind feeding electricity back into the grid, outline the requirements, and assess the current market situation. This will help you better evaluate whether waiting is worthwhile or which solution can benefit you right now.
What is a bidirectional wallbox?
A bidirectional wallbox differs from a standard charging station in one crucial way: it allows electricity to flow in both directions, from the grid or solar panel to the car and back again. A conventional charging station, on the other hand, can only send electricity in one direction and treats the car purely as a consumer.
The term encompasses three different applications. When charging at home, it's referred to as a bidirectional wallbox (V2H); when feeding power back into the public grid, it's V2G; and when supplying individual devices, it's V2L. All three use the same basic principle but differ in the destination of the electricity and the necessary technology.
Instead of buying expensive grid electricity, you cover your evening needs from the car battery, which was charged during the day with inexpensive solar power. This turns your vehicle into a mobile energy storage unit that does far more than simply drive. Especially when combined with your own solar system, this offers significant savings potential because you increase your self-consumption and can drive almost for free on many summer days.
How does bidirectional loading work?
In bidirectional charging via a wallbox, the direct current from the vehicle battery is converted back into usable alternating current. This conversion is performed either by the car's internal technology or by a separate device in the wallbox. Only after this conversion can the electricity be used in the household or fed into the grid.
To ensure this process runs smoothly and safely, the ISO 15118-20 standard comes into play. It forms the basis for bidirectional charging via AC power using a wallbox and ensures that the car and charging station communicate correctly. Without this common language, bidirectional charging via a wallbox simply doesn't work , even if both devices were technically capable of it.
Also important is the control system, which decides when to charge and when to feed energy back into the grid. It takes into account your current consumption, the car's charge level, and often the electricity price. This ensures that there's always enough range in the battery, while the excess energy benefits your household. The following overview compares the three options:
V2H, V2G and V2L at a glance
| Variant | Significance | Where the current flows |
|---|---|---|
| V2L | Vehicle to Load | in individual devices |
| V2H | Vehicle to Home | into your own home network |
| V2G | Vehicle to Grid | into the public power grid |
V2L is currently the easiest to use, often directly via a socket in the vehicle. V2H and V2G are more technically demanding and are still in the transition from pilot projects to widespread use in Germany. It will likely be several years before they become commonplace in everyday life.
AC or DC bidirectional wallbox
There are two basic approaches to the technology. With an AC solution, the necessary converter is located in the car; the wallbox remains relatively simple but requires compliance with the ISO 15118-20 standard. In contrast, with a bidirectional DC wallbox, the complex technology is integrated into the charging station itself.
A bidirectional DC wallbox is therefore usually more expensive and larger, but it functions more independently of the vehicle. Many current home charging solutions rely on this DC variant because the appropriate AC technology is only gradually becoming available in vehicles. Both approaches ultimately lead to the same goal, but utilize different hardware.
Which option is right for you depends primarily on your car. If it already supports AC bidirectional charging according to the current standard, a slimmer wallbox will suffice in the future. You should never base this decision solely on price , but always consider it in conjunction with your vehicle and solar system. Additionally, pay attention to manufacturers who reliably provide updates and spare parts, as the technology is evolving rapidly. Another important aspect is future-proofing, because anyone investing today wants to use the charging station for many years. Models with an open standard and regular updates will also work with new vehicles and electricity tariffs, thus safeguarding your purchase.
What qualifications you need
Several things need to come together for a wallbox to support bidirectional charging. First and foremost, you need a vehicle that actually supports energy return. Not every electric car is designed for this , although the number of compatible models is constantly growing. So, before buying, check whether your desired car has this feature.
For this, you need a wallbox designed for V2H (Variable to Power-to-Hyper) charging and a car whose onboard technology is compatible. Only if both sides are capable of feeding electricity back into the grid will the current actually flow back. Making a wallbox capable of feeding electricity back into the grid, if it isn't inherently that way, usually doesn't work and is rarely financially worthwhile anyway.
Then there's the bureaucratic aspect. Anyone feeding electricity back into the grid must register this with the grid operator and, if necessary, have their meter adjusted. A qualified electrician will clarify these points and ensure that everything is connected according to standards. For safety reasons related to feeding electricity back into the grid, such wallboxes for bidirectional charging should always be handled by a professional.
Is it possible to retrofit bidirectional charging?
Many owners of existing charging stations ask themselves whether it's possible to retrofit bidirectional charging. The honest answer is usually no. Both the car and the wallbox must support this function from the factory; a simple software update is rarely sufficient.
What's already available today is the simplest form of V2L. Using a suitable adapter, you can power individual devices directly from your car, for example while camping or in the garden. However, this isn't sufficient for charging into your home network ; that requires full bidirectional technology on both sides.
Anyone seriously considering retrofitting bidirectional charging will almost certainly need new hardware. Therefore, it's best to plan for this technology right from the start when buying a new car and charging station. This way, you avoid having to upgrade expensively later or replace a wallbox you just bought.
How much a bidirectional wallbox costs
The market for this technology is still young in 2026, and the range of models is limited. Therefore, if you're looking to buy a bidirectional wallbox, it's worth taking a close look at the current market situation and the few devices available. Buying hastily can easily lead to frustration and to technology that quickly becomes obsolete.
Today, you should expect to pay significantly more for a bidirectional wallbox than for a standard charging station. The complex technology and low production volumes drive up the costs. Bidirectional charging stations therefore often cost several times more than a simple wallbox , and this is in addition to potential costs for adapting your home's electrical connection.
If you're looking to buy a bidirectional wallbox, don't rush into it. New models are released every year, and prices are falling. Honest advice will help you decide whether waiting is worthwhile or if another solution offers you more benefits right now. We keep an eye on the market for you and will tell you when it's truly worth investing.
This is how you can make the most of your solar power today
As long as bidirectional wallboxes aren't widely available, you don't have to forgo high self-consumption. You can already achieve most of the benefit with a solar system and a home battery. This buffers your solar power and releases it in the evening, much like a bidirectional wallbox would do with a car.
No matching products found.
You can find suitable devices in our energy storage category ; our PV systems provide the necessary power generation . This combination makes you significantly more independent from your electricity provider today. Many home storage systems also offer an emergency power function that ensures your house continues to be supplied with electricity during a power outage.
As experienced electrical engineers, we'd be happy to show you how to charge your car with your own solar power and maximize your self-consumption. You can also read about how to make good use of surplus solar energy in our guide, "Making Good Use of Excess PV Power ." This way, you can get the most out of your solar power without waiting for the next generation of technology.
Frequently asked questions about the bidirectional wallbox
Which cars can charge bidirectionally?
More and more current electric car models support bidirectional charging right out of the box, often via the ISO 15118-20 standard. Whether your vehicle is compatible can be found in the manufacturer's specifications. The list of supported models grows noticeably with each model year, but retrofitting an older car is rarely possible.
How much does a bidirectional wallbox cost?
A bidirectional wallbox currently costs significantly more than a standard charging station because the technology is new and production volumes are low. Prices are expected to decrease as the technology becomes more widespread.
Is bidirectional charging already worthwhile today?
For most households, the technology will still be too new and too expensive in 2026. You can achieve a similar benefit for self-consumption today more cheaply with a solar system and a home battery storage system, from which you benefit immediately.
Do I need a DC or AC wallbox for V2H?
That depends on your car. If it supports AC bidirectional charging according to ISO 15118-20, an AC wallbox will suffice. Otherwise, a bidirectional DC wallbox, which handles the conversion itself, is required.
Conclusion
A bidirectional wallbox turns your electric car into a large energy storage system for your home and, in the future, for the grid as well. The technology is fascinating, but in 2026 it will still be in its early stages with few models and high prices. You don't have to wait for high self-consumption, though, because with a solar system and home battery storage, you can already achieve a lot today. Would you like to buy a wallbox for bidirectional charging as soon as the technology is ready? Contact us ; we'll give you honest advice and get in touch as soon as suitable models are available.
