Engineering Geology

ATLANTIS - An interdisciplinary feasibility study on hybrid pumped-hydro power storage of excess energy in open-pit coal mines


The world is currently desirous of elevating renewable energy uses to reduce greenhouse gas emissions, while phasing out fossil fuels at the same time. Generation capacities of wind and solar energy are currently being boosted to accelerate the energy transition from non-renewable to renewable. To be able to deal with peak demand on time, it is necessary not only to produce energy from renewable resources, but also to store excess energy during off-peak hours and supply it when the power demand is high. In this case, an efficient and sustainable energy storage system is required.

To support energy transition and allow a sustainable transition of conventional energy production from lignite, the usage of abandoned open-pit mines is an important opportunity for converting and storing renewable energy. Pumped-hydro power storage technology can make use of the abundant mines to store energy during the off-peak by pumping water from a lower reservoir in the mine uphill into an upper reservoir. During peak load, the system releases the stored water through turbines into the lower reservoir, just like in a conventional hydropower station. This allows a transition in terms of sustainable subsequent use of the mining landscape, reducing earthworks and transport, reducing environmental impacts, supporting green energy production, and opening new perspectives to transitioning coal regions.

The project

The focus of the overall project is to assess the technical and economic feasibility of transforming open-pit coal mines into hybrid energy storage projects. The possible utilization of abandoned coal mines into hybrid pumped-hydro power storage (HPHS) sites could add stability to the former coal regions and contribute to EU energy security. The investigations are focused on two study areas in Europe; one within the lignite deposits of western Macedonia in Greek, and another within lignite deposits in the southern part of the Lodz basin in Poland.

Project tasks at the Department of Engineering Geology

At the Department of Engineering Geology at TU Berlin, we are looking into the geotechnical impacts of HPHS operation with unsealed basins on slope stability, surface displacements and erosion. We aim to investigate the impact of the different filling levels of reservoirs during HPHS operation and consequent fluctuating groundwater levels on bank stability. Further geotechnical risks, such as possible subsidence and reservoir bank erosion will also be analysed.

Another focus of our group is the quantification of environmental risks for selected HPHS locations, such as potentially induced reservoir seismicity, erosion, and risk related to the construction and operation of HPHS on the specific lithological units. Finally, induced seismicity, embankment stability, vertical surface displacements and contamination of groundwater aquifers will be evaluated to propose elaborate recommendations for region-specific environmental monitoring.

Team and project partners

At the Department of Engineering Geology, Ershad Ud Dowlah Pahlowan, Anika Braun and Tomas Fernandez-Steeger are responsible for the project.

The project is conducted under a consortium of six partners across Europe from academia to industry.

  1. GFZ German Research Center for Geosciences, Germany (project coordination)
  2. Central Mining Institute, Poland
  3. Centre for Research and Technology Hellas, Greece
  4. PGE Gornictwo i Energetyka Konwencjonalna S.A., Poland
  5. Public Power Corporation S.A., Greece
  6. Technische Universität Berlin, Germany


The ATLANTIS project is funded through the Research Fund for Coal and Steel (RFCS)

Grant number: 101034022

Funding period: 2021 - 2024

Contact persons


Ershad Ud Dowlah Pahlowan

+49 30 314-70929

Prof. Dr.

Tomas Manuel Fernandez-Steeger

+49 30 314-72605