Registering balcony solar in Germany: what is actually required in 2026

What changed

Until 2024, operating a plug-in solar device required two separate filings: one with the grid operator and one in the Federal Network Agency's market master data register. In many grid areas this came with a form demanding datasheets, declarations of conformity and proof of a certified electrician.

The first solar package reduced all of that to a single, heavily shortened filing. Registration with the grid operator is gone without replacement — the operator is notified automatically through the register. In the register itself, plug-in devices now need five entries: location, commissioning date, module power, inverter power and meter number.

The deadline

The filing is due within one month of commissioning. Commissioning means the first time the system generated and exported electricity — not the purchase, and not the mounting.

Missing the deadline theoretically risks a fine. In practice, a late filing is accepted without objection; the problem only arises if nothing is filed at all and the grid operator discovers the system during a meter change.

The meter

An old Ferraris meter without a backstop runs backwards when the system exports. That used to be the main reason for grid operator registration, because the meter had to be replaced before the system could run.

A transitional rule now applies: the old meter may keep running until the operator replaces it as part of the smart meter rollout that is happening anyway. You need to arrange nothing and pay nothing. Until the swap, the backwards-turned share is effectively remunerated at the household electricity price — an advantage that disappears with the new meter.

Renting and ownership

Following the reform of tenancy and condominium law, plug-in solar devices count as a privileged structural alteration. Landlords and owners' associations can no longer refuse installation outright; they may only have a say in how it is done — the fixing method, for instance, or a consistent appearance towards the street.

There is no entitlement to a particular mounting method. If you want certainty, obtain consent in writing and document the fixing with photographs. For installations above the fall edge, proof of structural stability is sensible in any case.

Tax

Plug-in solar devices carry a zero VAT rate: no value added tax on purchase or installation. Income normally does not arise, because the surplus flows into the grid free of charge — so there is nothing to declare and no business registration.