In the future, the majority of the renewable energy will be generated isolated from consumers and electricity consumption hubs. Consequently, an extensive development of existing and new high-voltage power lines will be inevitable. The coalition agreement of the federal German government of July 1st in 2015 enacted a priority for underground power lines over overhead power lines for all large-scale, high-voltage power lines, revealing the significance of underground power lines in future transmission network expansions. On behalf of the German Ministry for the Environment, Nature Conservation and Nuclear Safety and in cooperation with the energy research institute of Lower Saxony, OECOS Ltd. compiled a study on the ecological impacts of 380-kV underground power cables and high-voltage direct current (HVDC) electric power transmission (also called electrical super highway) underground cables. The study investigated the consequences of underground cable laying from three distinct perspectives. OECOS Ltd. examined the consequences from an environmental perspective, whereas the University of Claushal-Zellerfeld examined the consequences from a juridical and the University of Hanover from an economical/technical perspective. In this light, OECOS Ltd. compared the environmental impacts of high-voltage underground power cables and high-voltage overhead power lines, since at that time overhead power lines still had permanent priority according to the German Law on the Energy Industry.
The resulting report ‘Ökölogische Auswirkungen von 380-kV-Erdleitungen und HGÜ-Erdleitungen’ (Ecological Impacts of 380 kV underground cables and HVDC electric power transmission underground cables) was published in the EFZN publication series of the Culliver Verlag Göttingen and is structured in four parts: Volume 4.1: Zusammenfassung (Summary); Volume 4.2: Umwelt (Environment); Volume 4.3: Ökonomie/Technik (Economy/Technology); and Volume 4.4: Recht (law). In a condensed version, the results of the research and development project ‘Ökölogische Auswirkungen von 380-kV-Erdleitungen und HGÜ-Erdleitungen‘ are also published in the manual for Environmental Impact Assessments under the heading ‘Umweltverträglichkeitsprüfung von Höchstspannungsleitungen - Freileitung und Kabel ‘ (Environmental Impact Assessment of high-voltage power – overhead power lines and cables).