Register plug-in solar 2026: the German register entry, step by step
A plug-in solar device up to 2,000 Wp and 800 VA only goes into the Market Master Data Register, at the latest 1 month after you first plug it in. The register informs the grid operator itself.
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Is your device plug-in solar, and what must you register?
Plug-in device under section 8(5a) EEG
Yes
| Limits | 2,000 Wp · 800 VA |
| Registration | register only (MaStR) |
| Deadline | 1 month after commissioning |
| Register entries | 1 |
To register a balcony power plant (Balkonkraftwerk) in Germany you now deal with exactly one office: the Market Master Data Register (Marktstammdatenregister, MaStR) run by the Federal Network Agency. The deadline is 1 month from commissioning (section 5(5) MaStRV). For devices up to 2,000 Wp of panels and 800 VA of inverter output, the grid operator may not demand any additional notice (section 8(5a) EEG). A 1,800 Wp kit stays within these limits and produces about 1,534 kWh a year on the German average at a 35° south tilt; a 2,400 Wp kit is no longer plug-in solar in law and needs an electrician and a grid application. A battery is a unit of its own in the register with its own number, so two entries instead of one. The public unit list shows 1,532,438 plug-in devices (retrieved 2026-10-15). Registration is free and takes about fifteen minutes with your receipt and the rating plate.
What the Solar Package I changed
Until May 2024 a balcony kit had two addressees: the grid operator, with its own form, and the Market Master Data Register. Since 16 May 2024 the version of section 8(5a) EEG sets out three things. A plug-in solar device (Steckersolargerät) has up to 2,000 Wp of panels and up to 800 VA of inverter output behind a household's point of supply. The duties under the register regulation remain. And the grid operator cannot ask for any notice beyond that. On top came section 10a(3) EEG: the device may run on the existing meter until the metering operator replaces it. What this means for your meter is explained under plug-in solar and the meter.
The deadline is short: 1 month from the day the plug first goes into the socket (section 5(5) MaStRV). Install in May and you are due in June.
Registration in five steps
Step one: an account on the web portal
On the Market Master Data Register you create a user account with an email address and password and confirm the link in the email. The account belongs to you as a person, not to the device; a second kit or a later battery goes into the same account.
Step two: you as the operator
You enter yourself as a private individual operator (Anlagenbetreiber), with name and address, and receive an operator number. Tenants are operators themselves, not their landlord.
Step three: the plug-in solar unit
Balcony kits have a shortened form; the Federal Network Agency describes a greatly simplified registration with few details. It asks for the location, the commissioning date, the panel output in Wp and the inverter output in VA. With several devices at the same flat the total counts: two kits of 1,200 Wp each exceed the limit together. Keep the invoice and rating plate at hand so the numbers are right.
Step four: the battery as a second unit
A battery is not a feature of the solar device but a separate unit with its own number. You create it separately, with usable capacity and power, and assign it to the same location. A battery added later triggers the one-month deadline again.
Step five: keep the confirmation
After saving, the portal shows the unit number. Keep the confirmation; the metering operator or your landlord sometimes ask for it. Your entry then appears in the public list of units, without your name.
Outside the limits, a different route
| 1,800 Wp, 800 VA | 2,400 Wp, 800 VA | |
|---|---|---|
| Plug-in device under section 8(5a) | yes | no |
| Notice to grid operator | not required | required |
| Connection | plug, by you | electrician |
| Running on the old meter | allowed until replaced | no |
| Output per year (German average, 35° south) | 1,534 kWh | 1,765 kWh |
The extra panel area adds only 231 kWh at 800 VA but costs you the simple route. How much an inverter clips off at peak times is worked out in the guide plug-in solar 800 watt.
Common mistakes in the entry
The most frequent one is mixing up output figures: the register wants the panel output in Wp and, separately, the inverter's output. An inverter limited by software to 800 VA is entered with that value. The second is the date: what counts is first operation, not purchase. Third, many forget the battery because it came in the box. If you also own a rooftop system, its longer list of duties is under Market Master Data Register; the plug-in device is not added to it but stays a unit of its own. The Federal Network Agency answers individual cases in its questions and answers on plug-in solar.
What happens to your data after the entry
The entry is not an application that anyone has to approve. The device may run from day one; the deadline only concerns the registration. In the background a chain starts that the law describes in section 10a(2) EEG: the Federal Network Agency asks the grid operator to check the data in the register. The metering operator then fits your metering point with a bidirectional meter (Zweirichtungszähler) or a smart metering system, without you having to order it. The swap can take months; until then the device keeps running on the old meter.
What becomes public is the output, the date, the postcode and the town, but not the street, house number or coordinates of a unit up to 30 kilowatts, and no data about you as a private person (section 15 MaStRV). The 1,532,438 devices the register counts today come from exactly these entries.
Missed the deadline: what to do now
If you have run a device for months and forgot the entry, add it now with the real date of first operation, not today's date. A wrong date would be the actual inaccuracy. Plug-in solar earns no feed-in tariff that could be cut, because the surplus goes to the grid unpaid. The late entry ends the breach of the registration duty for the future. The same goes for a forgotten battery: add it as a second unit and link it to the solar device at the same location.