The eastern Ruhr area with Dortmund as its centre is an intensive assessment region for us. On the converted industrial brownfields — Phoenix West, Westfalenhuette, Hoesch site — large-scale PV systems are being developed where the DONETZ TAB determine success or delay. Our expert assessors regularly inspect grid compatibility here and provide technical support throughout the connection process.
DONETZ operates the electricity distribution network in Dortmund with approximately 600,000 inhabitants. On converted industrial sites such as Phoenix West, increasingly larger PV projects are being developed that require thorough grid compatibility assessments.
Anyone planning a ground-mounted system, a solar carport or a storage container in Dortmund should know the subsoil. As the mining authority, the Arnsberg District Government provides information on the mining situation and the risk of mining damage for plots in North Rhine-Westphalia. The flat fee is EUR 30. Owners or authorised representatives may apply; a site plan showing the plot boundaries and a land register extract are required. The portal Gefährdungspotenziale des Untergrundes in NRW gives a first overview.
For photovoltaics and battery storage this information is more than a formality. Foundations of mounting structures and containers depend on the bearing capacity of the ground. For rooftop systems on halls with mining damage, tilting of the structure can change the load assumptions. For valuations and damage assessments on former colliery and industrial sites, the mining information is therefore one of the documents we request.
The city reopened its funding programme for private photovoltaic systems in February 2026. New systems of 5 kWp or more on single and two-family houses receive a flat EUR 1,000. Income limits of EUR 75,000 for single persons and EUR 150,000 for joint assessment apply. In the first round, more than 200 applications arrived within a short time. Approvals were put on hold until 31 March 2026 because of the budget situation.
| Standard | Scope | PV Relevance |
|---|---|---|
| VDE-AR-N 4100 | TAR low voltage | Mandatory: meter location, 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 DONETZ | 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 DONETZ through a simplified procedure.
Dortmund is located in the Amprion control area. The responsible transmission system operator (TSO) is Amprion GmbH. Amprion is responsible for system stability in the extra-high voltage grid (220/380 kV). At the regional distribution grid level, Westnetz is also an active operator.
| Level | Operator | Voltage Level | PV/BESS Relevance |
|---|---|---|---|
| Transmission grid | Amprion | 220-380 kV | System stability, EEG feed-in |
| Distribution grid | DONETZ | 0.4-20 kV | TAB, grid connection, meter location |
| Customer installation | System operator | 0.4 kV (LV) | PV generator, BESS, inverter |
Regional factors for planning and assessment in Dortmund:
Dortmund's former steel and coal sites (Phoenix-West, Westfalenhuette) are being converted into solar business parks. Contamination assessments and soil remediation certificates are required before ground-mounted PV installation.
In northern Dortmund, mining-related subsidence occurs. Foundations for ground-mounted PV and storage containers require geotechnical assessments for load-bearing capacity.
Dortmund's logistics centres in Brackeler Feld and at Westfalendamm offer flat roof areas of 10,000-50,000 m². Systems above 500 kWp require medium-voltage connections and protection concepts per VDE-AR-N 4110.
In the Dortmund city area, both DONETZ and Westnetz are active as distribution grid operators. Responsibility must be clarified based on the connection address before project start.
| Occasion | Our Service |
|---|---|
| Acceptance assessment | TAB conformity inspection, 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) or 4110 (medium voltage) plus supplementary TAB from Dortmunder Netz GmbH (DONETZ).
Exclusively through a certified electrical contractor. Details: DONETZ 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 of work. Contact: info@pv-bess-assessor.com or +49 89 97 31 37 43.
For systems from 30 kWp, medium voltage connections, grid compatibility issues, disputes with the grid operator, acceptance inspections of commercial systems.
We know the DONETZ TAB from daily practice. Get in touch with us.
Contact Us| Address | Dortmunder Netz GmbH, Ostwall 60, 44135 Dortmund |
| Phone | 0231 544-0 |
| info@do-netz.de | |
| Website | DONETZ — TAB |
We assess nationwide. These pages summarise the TAB of each grid operator:
Augsburg Berlin Bielefeld Bonn Bremen Dresden Düsseldorf Duisburg Frankfurt Hamburg Hannover Karlsruhe Köln Leipzig Mannheim München Münster Nürnberg Stuttgart
Last updated: 2026-09-28 | Author: Christoph S. Prestele, TUV-certified Expert Assessor | Source: Dortmunder Netz GmbH (DONETZ)