Underground high voltage cables (UGCs) – Environmental research and on-site development of innovative solutions






Amprion has been conducting a long-term ecological research programme in rural areas, consisting of 20 years of field experiments, and of validation of experimental findings through monitoring of an UGC project in Germany. Through this project, Amprion aims to increase the understanding of UGCs’ thermal and hydrological impact on the soil, and of any resulting ecological impacts on flora and fauna. The practice’s findings will offer insights on how to predict and reduce impacts of construction and operation during the project planning phase.



  • Field experiment findings show a low (or negligible) ecological impact on agricultural production and soil properties
  • Amprion carried out an ecological assessment using real data from field experiments, rather than from a theoretical model
  • The practice aims to reduce UGC impact on soil and farmland, accelerate permitting processes and foster acceptance of UGCs through enhanced learning and understanding, especially with farmers and local stakeholders  



The practice can be applied to any project location and its findings can aid future similar projects through knowledge transfer of the developed methodology, monitoring and measuring approaches.  


Main information:

Underground cables with high voltage ratings have not been widely used in rural areas in Europe. Due to the lack of knowledge with regard to the ecological impact of UGCs, it is not possible to forecast potential negative impacts and address them accordingly during a project’s planning phase. Amprion’s comprehensive long-term research programme spanning over 20 years aims to address this knowledge deficit.  

Starting in 2005 with a 5-year field experiment of artificial soil heating, the thermal effects for different operating scenarios and hydrological conditions were simulated and recorded. Following this, another 5-year experiment was carried out on a 110kV UGC system operating under extreme loads and different bedding materials. Growth and yield were monitored during cultivation experiments in order to establish the effects on agricultural crops. In 2015, the final stage of the practice started; a 10-year monitoring programme of the first 380kV AC (3.6GW), 3.4km UGC project in Germany (Raesfeld), where an instrument station provides continuous monitoring of the soil’s properties.  


Additional information:

Amprion, a German TSO operating the high voltage grid from Lower Saxony down to the Alps, carried out the practice in cooperation with the Albert-Ludwigs University of Freiburg (Chair of Soil Ecology) and ERM (environmental consultancy). Other stakeholders that were part of the Steering Committee included the University of Südwestfalen, the Westphalia-Lippe Agricultural Association, the Chamber of Agriculture NRW, and several experts and farmers.  


RGI gratefully acknowledges the EU LIFE funding support:

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Funded by the European Union. Views and opinions expressed are however those of the author(s) only and do not necessarily reflect those of the European Union or the LIFE Programme. Neither the European Union nor the granting authority can be held responsible for them.