Bi-directional Meter for Balcony Power Plants – Everything You Need to Know

With the ongoing boom in balcony power plants in Germany, technical and legal details are also coming into focus. One of the most central questions homeowners and tenants ask concerns the electricity meter. Do I need a bidirectional meter? What exactly is that, and what regulations apply in 2026?

In this comprehensive guide, we will provide you with well-founded, practical, and understandable answers so that you are legally secure and optimally prepared.

---

What is a bidirectional meter? A simple overview

A bidirectional meter is a modern digital electricity meter capable of separately recording two energy flows:

1. Consumption: The amount of electricity you draw from the public grid.

2. Feed-in: The amount of electricity your balcony power plant produces but is not immediately consumed and therefore flows into the public grid.

Think of it this way: On a sunny afternoon, your mini solar system produces more energy than your refrigerator and appliances need. This surplus is not wasted but "exported" to the grid. A bidirectional meter accurately measures this fed-in amount separately from your consumption.

In contrast, outdated, black Ferraris meters (with the spinning disk) can run backward due to feed-in – a condition that is no longer legally permissible today.

---

Which meter do I need for a balcony power plant? The three legal options

The basic rule is simple: For operating a balcony power plant, you need a meter that cannot run backward. In practice, there are three common, permissible meter types:

Meter Type	Description	Ideal for...
Modern Measuring Device (mME)	A digital meter with an integrated backstop. It stops counting when electricity is fed in but does not record the feed-in separately.	Standard operation of a balcony power plant up to 800 watts, with a focus on self-consumption.
Bidirectional Meter	Measures both electricity consumption and feed-in in separate registers (identifiable by codes 1.8.0 for consumption and 2.8.0 for feed-in).	Anyone who wants accurate feed-in measurement or is requested to do so by the grid operator.
Smart Metering System (Smart Meter)	A digital meter with a communication module (gateway) that automatically sends data to the grid operator.	Only becomes mandatory for larger systems or high annual consumption (> 6,000 kWh).

For most balcony power plants, a modern measuring device with a backstop is completely sufficient.

---

Can the electricity meter run backward with a balcony power plant? A clear no!

This is one of the most frequently asked questions, and the answer is unequivocal:

👉 No, a backward-running electricity meter is prohibited in Germany.

Even if this was sometimes tolerated in the past, this practice is now considered a misdemeanor and can even be classified as tax evasion or fraud in some cases. The reason: a backward-running meter illegally offsets the fed-in electricity against the consumed electricity, which falsifies the billing.

Therefore, a meter with a backstop or a bidirectional meter is an absolute must.

---

Meter replacement: Who is responsible and how does it work?

Replacing your electricity meter is a standardized process that you are not allowed to carry out yourself.

Who is responsible?
Exclusively the meter operator, which in most cases is your local grid operator.

How does the process work?

1. System registration: You register your balcony power plant in the market master data register (MaStR) of the Federal Network Agency. Parallel registration with the grid operator has not been mandatory for most systems since 2024, as the data is transmitted from the MaStR.

2. Automatic check: The grid operator checks after registration whether your installed meter meets the technical requirements.

3. Organization of the change: If the grid operator determines that an old meter (e.g., Ferraris meter) is installed, they will organize the replacement for you free of charge. You will be contacted to arrange an appointment.

4. Installation: A certified technician carries out the replacement, which usually only takes 20 to 30 minutes on site.

---

Costs for meter replacement and operation

Good news: For the pure replacement of the meter during the registration of a balcony power plant, there are generally no one-time costs.

The costs for meter operation are legally capped and are billed via an annual fee, which is usually offset against your electricity bill:

• Modern Measuring Device: Maximum €20 per year.

• Bidirectional Meter: The costs are often at a similar level, also around €20 per year.

The times when significantly higher fees were charged for a bidirectional meter are largely over.

---

FAQ – Your most frequently asked questions answered quickly

Question	Answer
Is a bidirectional meter mandatory?	No, not necessarily. A meter with a backstop is mandatory. A bidirectional meter is one of several permissible options.
What happens if I don't have my old meter replaced?	After registering your system, the grid operator will automatically and free of charge arrange for the replacement to ensure compliance with the law.
Do I get money for the electricity fed in?	For balcony power plants, the focus is on self-consumption. A feed-in tariff is unusual and usually not economical. Excess electricity is usually fed into the grid free of charge.
Can I replace the meter myself?	No, absolutely not. This is legally prohibited and life-threatening. Only certified specialist personnel may work on the meter.
How do I recognize a meter with a backstop?	Modern digital meters generally have a backstop. A symbol (often a gear with a stop arrow) can indicate this. If in doubt, the type plate or the grid operator can provide information.

---

Conclusion: Security and transparency for your balcony power plant

A bidirectional meter is an excellent, but not always strictly necessary, component for operating a balcony power plant. It is crucial that your meter meets the legal requirements and does not run backward.

Since grid operators replace outdated meters free of charge after you register your system, you as a consumer hardly need to worry. The process is designed to make it as easy as possible for you to get started with solar energy. A modern meter not only provides you with the necessary legal certainty but also creates the transparency to optimize your energy consumption and get the most out of your balcony power plant.