Retrofitting Bidirectional Charging: What’s Actually Possible in Germany in 2026

Using your electric car as a battery for the whole house is a compelling idea: a vehicle battery of 60 to 80 kWh holds several times the energy of a typical home storage system, and it is already parked in your garage. No wonder many EV drivers ask about retrofitting bidirectional charging. The short answer: on the car side it is often a software matter, but on the wallbox side it almost never is, because you usually need a new unit approved by the car maker.

On this page we give you an honest assessment as a specialist installer, without marketing promises. Vehicle-to-Home (V2H) works in Germany today with some vehicles and matching DC wallboxes. Vehicle-to-Grid (V2G) is only just starting. Below we explain step by step what that means, which rules apply since January 2026 and what you should check.

Retrofitting bidirectional charging: key facts at a glance

V2L, V2H, and V2G: Understanding the Differences

Before discussing retrofitting, it is worth separating the three terms, as they are often confused:

• Vehicle-to-Load (V2L): the car supplies power to individual devices through a socket or adapter, such as tools, camping or garden equipment. This works without a special wallbox or registration, but it does not replace a home battery.
• Vehicle-to-Home (V2H): the car supplies stored energy to your home’s electrical system. For homes with solar PV this is the most interesting option, and where the practical benefit lies today.
• Vehicle-to-Grid (V2G): power flows back into the public grid, paid for through a suitable tariff. Technically and legally the most demanding case; for private households there are only a few offers so far.

For most households V2H is the goal: using self-generated solar power from the car in the evening instead of exporting it for a few cents.

What Has Changed in 2026? The Real Situation

The real progress lies less in vehicle technology than in the legal framework. Four points matter, and for each it pays to look closely at what actually applies.

Grid charges: the charging point counts as storage

Under the amendment to the Energy Industry Act (EnWG) passed by the Bundestag in November 2025, § 118(6) EnWG has referred to § 21 EnFG since 1 January 2026. That provision treats charging points for electric vehicles as electricity storage. The aim is that power drawn from the grid into the car and later fed back into the grid is not charged grid fees twice. This mainly affects V2G. With pure V2H using your own solar power, hardly any grid power passes through the car anyway.

Bidirectional charging and electricity tax: V2H settled, V2G not fully

§ 5a(3) of the Electricity Tax Act (StromStG) states that no electricity tax arises when power from the vehicle battery is consumed on site via the charging point without using the public grid. For V2H this is settled. For feeding back into the public grid (V2G), the tax treatment is not yet fully resolved in all cases, and industry associations are calling for improvements.

MiSpeL: new rules from the Federal Network Agency

On 1 October 2026 the Bundesnetzagentur issued its determination on the market integration of storage and charging points (MiSpeL). Bidirectional charging points are now largely treated like electricity storage. They may mix solar and grid power without losing the EEG feed-in support for exported solar power. Households with PV systems up to 30 kWp get a simplified flat-rate option that usually needs only one meter. Two limitations: until the end of September 2027, applying the rules requires the consent of the grid operator and the metering operator. And the flat-rate option only applies once the European Commission has granted state-aid approval.

Technical rule: VDE-AR-N 4105

The new edition of VDE-AR-N 4105 (March 2026) contains requirements for charging equipment that can feed power back for the first time. It is a technical application rule, not a law, but grid operators require compliance. For you this means the wallbox and the car need the manufacturer’s certificates, otherwise the system may not feed power back into the home grid.

Bidirectional charging: AC or DC?

With DC solutions the inverter sits in the wallbox and the car delivers direct current. With AC solutions the car converts the power itself. The solutions that work reliably in Germany today are mostly DC-based, with a wallbox the car maker has explicitly approved. So don’t be misled by «BiDi-ready»: hardware-prepared does not mean usable.

Can Bidirectional Charging Actually Be Retrofitted?

Often yes, but rarely by simply «unlocking» it. Whether retrofitting bidirectional charging works for you depends on three factors:

The vehicle: often a software update

The car must support discharging as approved by the manufacturer. For many models the software decides, not the connector. One example: Volkswagen enables bidirectional charging for all ID. models with the current ID. Software 6, and for older vehicles from Software 3.5 only with a battery of 77 kWh or more. For cars without approval there is no conversion that lets you add the function yourself.

The wallbox for bidirectional charging: usually a new unit

A standard wallbox cannot feed power back. You need a genuine bidirectional wallbox that your car maker has approved for V2H. Anyone retrofitting bidirectional charging today therefore replaces the wallbox in most cases or adds a second one. Whether the existing supply cable and the protection in the meter cabinet suit the new unit is something we check on site.

Home wiring, metering and registration

Integration requires work on the home electrical system by a registered electrical contractor, a suitable metering concept and registration with the grid operator. This is exactly where we come in: we install bidirectional DC charging systems with our own electricians, including the metering concept and registration.

Which cars support bidirectional charging today

The list changes constantly. The manufacturers themselves describe these two examples for Germany:

Other manufacturers offer V2L or have announced bidirectional charging. Before buying, check with the manufacturer whether your model and software version are approved for V2H in Germany, or let us check it for you.

What You Need for a Bidirectional Charging Retrofit

Checklist: retrofitting bidirectional charging

• Compatible vehicle: with discharging enabled by the manufacturer and current software.
• Bidirectional wallbox: currently mostly DC wallboxes. Look for genuine V2H approval for your car, not just «BiDi-ready».
• Energy management system (EMS): so the car only discharges when solar power is not enough, and a minimum charge remains for your next trip. More on our energy management system page.
• Meter cabinet and metering concept: space for protection devices and, where needed, another meter. For V2G a smart metering system is usually part of the offer.
• Registration with the grid operator: with the manufacturer’s VDE-AR-N 4105 certificates. We handle this registration for you.

V2H with Solar Power: Why This Combination Is So Powerful

Bidirectional charging has the biggest impact together with a photovoltaic system. During the day the PV system charges the car; in the evening the car returns part of that solar power to the house. Depending on your consumption profile this can raise self-consumption significantly, using a battery you already own. For comparison: without storage, households typically use 25 to 35 % of their solar power themselves, with a stationary battery 55 to 70 %.

Every kilowatt-hour you use yourself saves buying power from the grid. With an assumed electricity price of 32 ct/kWh and a feed-in tariff of 7.70 ct/kWh (partial feed-in up to 10 kWp, commissioned from 1 August 2026), that is about 24 ct for every kilowatt-hour you use instead of exporting. The maths only works if the car is actually at home in the evening.

This is especially interesting if your PV system has no separate home battery. If you commute during the day, a stationary home battery is often more reliable because it is always connected. Backup power from the car is only possible if the system explicitly supports it; see solar backup power systems. How wallbox, PV and heat pump work together is explained in our guide on solar systems with EV charging stations.

Is It Economically Worthwhile?

The honest answer depends on how you use it:

• PV self-consumption (V2H): the clearest benefit. Using self-generated power from the car in the evening cuts electricity costs directly.
• Dynamic electricity tariff: charge when power is cheap, use it when it is expensive. This works but pays off more slowly.
• V2G revenue: the first offers exist. With the BMW/E.ON offer, for example, the providers say you receive a bonus for the time the car is plugged into the wallbox, up to 720 € a year.

What bidirectional charging costs

Reliable market prices exist only for individual systems so far. At launch, the BMW Wallbox Professional was listed at around 2,094 € in the manufacturer’s configurator, excluding installation. DC systems from other manufacturers cost considerably more depending on equipment, and some are only sold together with a home battery. For comparison: a standard 11 kW wallbox usually costs around 1,200 to 3,500 € including installation; details on our home wallbox installation page.

Actual payback periods depend heavily on electricity prices, driving patterns and hardware costs. In a consultation we work this out honestly for your situation, without selling you something that does not pay off.

Incentives and Funding: What’s Available in 2026?

There is currently no federal grant for private wallboxes in owner-occupied homes, including bidirectional models. The former KfW programme 442 has ended. For the PV system and battery there is the KfW 270 programme, which is a loan, not a grant.

What you do get: a newly installed wallbox above 4.2 kW counts as a controllable consumption device under § 14a EnWG. You pay reduced grid charges, and in return the grid operator may temporarily limit charging power to no less than 4.2 kW if the grid is at risk of overload. Regional programmes from federal states, municipalities or utilities change frequently; see our overview of solar subsidies in Germany.

Safety and Registration: Not a DIY Project

Installing a bidirectional wallbox means working on the home electrical system and belongs in the hands of a registered electrical contractor. Charging equipment must be notified to the grid operator before commissioning; above 12 kVA its consent is also required under § 19(2) NAV. Because a bidirectional wallbox can feed power back, the VDE-AR-N 4105 certificates are added, and for V2G and the MiSpeL rules, coordination with the grid and metering operator.

As a regional specialist in Lower Saxony and Bremen, we handle planning, installation of your bidirectional DC charging system by our own electricians in line with VDE and TAB, and registration with the grid operator and, where required, in the Marktstammdatenregister, all from a single source.

Conclusion

V2H is no longer just a future topic. With the right combination of vehicle and approved wallbox it is a real option, especially together with a photovoltaic system. V2G for private households is still at an early stage. Before retrofitting bidirectional charging, check three things: your car’s approval, the matching wallbox, and whether the car is at home often enough.

Thinking about retrofitting bidirectional charging? We check whether your vehicle, the wallbox and your meter cabinet fit together, and we install your bidirectional DC charging system. Request your free, no-obligation quote. We advise you honestly and free of charge, by phone on 0511 3360603 or via WhatsApp at +49 176 2399 8536.

Sources:

1. § 118 EnWG (para. 6), gesetze-im-internet.de
2. § 21 EnFG (charging points as storage), gesetze-im-internet.de
3. § 5a StromStG (charging points, power from vehicle batteries), gesetze-im-internet.de
4. Bundesnetzagentur: MiSpeL determination, 1 Oct 2026 (German)
5. DKE: VDE-AR-N 4105:2026-03
6. Volkswagen: bidirectional charging (German)
7. electrive: BMW and E.ON launch V2G offer for private customers (German)
8. Solarserver: EnWG amendment clears the way for bidirectional charging (German)

Note: This article gives a general overview (as of November 2026) and does not replace legal or tax advice. Vehicle and wallbox approvals change constantly.