Erfurt's Energy Transition: High Voltage for the Future

The Energy Transition in Erfurt: A High-Voltage Line for the Future

The state capital of Erfurt is not always in the spotlight in Germany's energy policy. However, in January 2026, the 380-kV high-voltage transmission line project Vieselbach–Eisenach–Mecklar (BBPlG Project No. 12) demonstrated that Erfurt and its surrounding regions are key players in the development of Germany's power grid. This project is part of the energy transition, which aims to expand renewable energy sources and ensure the stability of the power grid.

Technical Challenges and Innovations

The 380-kV line between Vieselbach and Mecklar is part of a larger grid expansion coordinated by 50Hertz Transmission GmbH and TenneT. The project's goal is to increase transmission capacity from 2,520 A to 4,000 A. This is made possible by replacing the existing overhead line with high-temperature low-sag (HTLS) conductors. HTLS wires have the advantage over conventional aluminum-steel conductors in that they remain stable at higher temperatures and exhibit less sag. This results in fewer interventions in the landscape and allows for higher performance within the same corridor width.

Another technical highlight is the replacement of towers with alignment towers. These are necessary because the maximum wire length on a drum is limited and occupational safety regulations must not be exceeded. In total, 18 towers will be replaced, three of which will be replaced with taller towers to ensure the required minimum ground clearance is maintained.

Legal and Planning Frameworks

The project is subject to a wide range of legal requirements. The planning approval is carried out under the Grid Expansion Acceleration Act (NABEG) and is part of the Federal Grid Expansion Plan. The Federal Network Agency (Bundesnetzagentur, BNetzA) is the responsible authority and granted the planning approval on August 14, 2024. The first planning amendment, implemented in January 2026, includes, among other things, the removal of bird protection markers and the reduction of tower height in section A, which led to the removal of night marking.

The planning is also part of the National Electricity Development Plan (NEP) 2035 and 2037/2045. Under § 12e of the Energy Industry Act (EnWG), the energy-economic necessity and urgent need have been confirmed. The Strategic Environmental Assessment (SUP) under § 43m EnWG has also been carried out to ensure the project is environmentally compatible.

Environmental and Nature Conservation

One of the central topics in the planning is the handling of nature conservation areas. The overhead line runs through several Natura 2000 sites and priority areas for agriculture, flood protection, and open space protection. The planning documents contain detailed emission calculations showing that the limit values for electric and magnetic fields according to the 26th Federal Immission Control Ordinance (26. BImSchV) are complied with. The TA Noise and the Baulärm-Verordnung (Construction Noise Ordinance) are also taken into account.

To minimize the impact on nature, numerous mitigation measures are planned. These include the restoration of arable and grassland areas after the completion of construction work, protective measures for flood-prone areas, and the establishment of bat replacement roosts and bird nesting boxes. The city of Erfurt has also requested that the maintenance period for newly planted trees be extended to five years and that the lower-level nature conservation authority be involved in the planning and implementation of compensatory measures.

Outlook: Erfurt's Role in the Energy Transition

The 380-kV line Vieselbach–Eisenach–Mecklar is more than just a technical challenge. It is a symbol of the transformation of Germany's energy supply system. As part of this transformation, Erfurt will play a key role in the coming years. The city and its region must learn to deal with the requirements of energy policy—balancing technological progress, environmental compatibility, and social acceptance.

The experiences gained from this project will also be valuable for future grid expansion measures in Thuringia and beyond. Erfurt can establish itself as a model for sustainable energy policy, where innovation and environmental compatibility go hand in hand.