There are great expectations towards underground transmission lines, especially with regard to a greater degree of local acceptance. While underground cables are more frequently used at the distribution level (110 kV and lower), they are not state-of-the-art in the extra high voltage range (380 kV).
They are also more expensive and more difficult to operate than overhead lines. In case of disturbances, recent experiences have shown that it can take months before a cable can be put into operation again, while overhead lines can often be used within a matter of days. The impact of underground cables on the environment is not lower either, as it massively affects the soil, as well as water management and landscape in certain cases.
For this reason, the decision to install a power line as an overhead line or an underground cable is always made on a case-by-case basis. Underground cables should be used where this is more advantageous to and economic for man, nature and wildlife. In our experience, cable solutions should be tested where this has a lesser impact on the landscape for close residents. However, in nature reserves, it is our experience that underground cables have a much greater impact on nature than traditional overhead lines.
The legal possibilities to test individual cable sections for larger projects are currently very limited. It is nevertheless worthwhile to make specific target-oriented analyses of special cases in consultation with all social players. The option introduced in the draft law for the new EEG that also allows partial underground cable solutions to be tested for individual cases in the scope of direct current projects (South-East DC Passage) is therefore very useful.