In the state of Bremen — from the harbor quarters to the residential neighborhoods of Schwachhausen and Horn-Lehe — we provide expert assessor support for PV projects from planning through commissioning. The TAB of wesernetz apply uniformly for Bremen and Bremerhaven and form the basis of every technical evaluation. Particularly for commercial installations near the harbor, we assess not only TAB conformity but also the elevated corrosion protection requirements.
wesernetz Bremen GmbH operates the electricity distribution grid in Bremen and Bremerhaven for approximately 570,000 inhabitants. The coastal proximity results in elevated requirements for corrosion protection of electrical installations. Bremen has one of the highest PV densities among northern German major cities.
Bremen introduced its solar obligation for existing buildings first. Under the Bremen Solar Act (BremSolarG), anyone starting a fundamental roof renovation since 1 July 2024 must install a PV system. This means renewing the top roof layer on at least 80 percent of the area. The obligation applies from 25 m² of roof area and requires at least 1 kW of module capacity. Owners have two years after completion of the renovation to comply.
For new buildings the act has applied since 1 July 2025, based on the date of application. On roofs of more than 50 m², at least 50 percent must be covered with solar modules. The system must be in operation when the building is first used. The authority only requires proof on request, for example an extract from the Market Master Data Register or documents from the grid operator.
For existing buildings the obligation lapses if the roof lacks sufficient load-bearing capacity. The Senate press office names this case explicitly as an exemption. No application is needed, as the exemption applies by law. If the authority asks, however, the owner must be able to prove the insufficient load-bearing capacity. A structural or building survey is the usual means. We document the roof build-up, load reserves and fixing options.
| Regulation | Scope | Relevance for PV |
|---|---|---|
| VDE-AR-N 4100 | TAR low voltage | Mandatory: meter panel, service entrance, protection concept |
| VDE-AR-N 4105 | Generation systems on LV grid | Mandatory for connection to the low-voltage grid |
| VDE-AR-N 4110 | TAR medium voltage | Mandatory for connection to the medium-voltage grid |
| Supplementary TAB wesernetz | Regional supplements | Grid operator-specific requirements |
| Requirement | Specification |
|---|---|
| Meter type | eHZ, three-point mounting |
| Surge protection | Type 1+2 combined arrester (mandatory for new systems) |
| SLS switch | selective circuit breaker upstream of the meter |
| Space reserve | 1 slot for smart meter gateway |
| Equipotential bonding | to main earthing busbar |
Balcony power plants up to 800 W can be registered with wesernetz via the simplified registration procedure. Bremen supports plug-in solar devices through the state program.
Bremen is located in the TenneT-control area. The responsible transmission system operator (TSO) is TenneT TSO GmbH. TenneT is responsible for system stability in the extra-high voltage grid (220/380 kV).
| Level | Operator | Voltage Level | Relevance for PV/BESS |
|---|---|---|---|
| Transmission Grid | TenneT | 220–380 kV | System stability, EEG feed-in |
| Distribution Grid | wesernetz | 0,4–20 kV | TAB, grid connection, meter panel |
| Customer System | System Operator | 0.4 kV (LV) | PV array, BESS, inverter |
Regional factors for planning and assessment in Bremen:
Bremen's proximity to the North Sea brings elevated humidity and salt aerosols. PV modules in the Überseestadt and harbor quarters should be tested for salt mist resistance per IEC 61701.
Bremen Überseestadt offers enormous flat-roof PV potential across over 100 hectares of commercial space. Converting former harbor buildings requires structural proof for roof load capacity.
In Bremen's residential districts Schwachhausen and Horn-Lehe, the low-voltage grids are reaching their limits with PV expansion. wesernetz increasingly requires intelligent feed-in controls.
| Occasion | Our Service |
|---|---|
| Acceptance Assessment | TAB conformity check, defect report |
| Dispute with grid operator | Independent technical evaluation |
| Systems from 30 kWp, medium voltage, capacity bottleneck | Grid compatibility assessment, grid analysis, alternative concepts |
| Defect Assessment | DIN VDE 0100-600, thermography, EL |
VDE-AR-N 4100 and 4105 (low voltage) and 4110 (medium voltage) plus supplementary TAB der wesernetz Bremen GmbH.
Exclusively through a certified electrical contractor. Details: wesernetz website.
Must comply with VDE-AR-N 4100 and supplementary TAB. Older cabinets (pre-2010): eHZ, surge protection, SLS. Cost: EUR 1,000-2,500.
Depends on system size and scope. Contact: info@pv-bess-assessor.com or +49 89 97 31 37 43.
For systems from 30 kWp, medium voltage, grid compatibility issues, disputes with the grid operator, acceptance of commercial systems.
We are familiar with the TAB of wesernetz from daily practice. Get in touch with us.
Get in Touch| Address | wesernetz Bremen GmbH, Theodor-Heuss-Allee 20, 28215 Bremen |
| Phone | 0421 359-0 |
| info@wesernetz.de | |
| Website | wesernetz — TAB |
We assess nationwide. These pages summarise the TAB of each grid operator:
Augsburg Berlin Bielefeld Bonn Dortmund Dresden Düsseldorf Duisburg Frankfurt Hamburg Hannover Karlsruhe Köln Leipzig Mannheim München Münster Nürnberg Stuttgart
Last updated: 2026-11-03 | Source: wesernetz Bremen GmbH