Energy sheet pile walls consist of conventional sheet piles that are factory-fitted with absorber pipes, thus transferring the established principle of concrete geostructures to the technology of sheet piling. Sheet piles are generally used as a sealing component in the presence of groundwater and therefore are usually located in an energetically favorable soil. In the area of harbor or hydraulic engineering, there is even direct contact with a surface water body. Due to the high heat capacity of water and the stable temperature regime, surface waters have a particularly high thermal energy potential. In contrast to the subsurface, which is being increasingly exploited by geothermal plants, the thermal energy potential of open waters has so far remained virtually unexploited.
Energy sheet piles can be used for new constructions, upgrades or restoration of existing sheet pile structures. In addition, prefabricated add-on elements are available for subsequent thermal activation and refurbishment of existing structures in contact to an open water body. These are simply installed by curtaining them on the water side and thus directly in the open water.
With these patented systems for thermal activation of sheet pile walls, an efficient and sustainable option is available for a decentralized exploitation of the shallow subsurface and in particular of open water bodies in order to permanently provide clean renewable energy for climatization of buildings.
Conceptual model of an energy sheet pile wall
Energy sheet pile wall as shore protection
Add-on element in the water in the large-scale test station
In order to achieve the international goal of limiting global warming to 1.5 °C, fossil fuel energy supplies shall be gradually reduced and simultaneously the expansion of renewable energies needs to be accelerated within the framework of the energy transition. In this context, the geotechnical profession is also challenged to make an effective contribution to the reduction of CO2 emissions and thus to climate protection by applying sustainable methods and innovative approaches in the field of foundation engineering.
In Germany, a large share of end energy is used to provide heating (space heating and hot water) or cooling. An alternative to the use of fossil fuels for building climatization is the exploitation of shallow geothermal energy. For this purpose, building components in contact with the ground are increasingly being thermally activated in foundation engineering. In this process, absorber pipes are usually integrated into concrete components which are necessary in any case for static or sealing purposes. These absorber pipes later form the closed primary circuit of the geothermal system, through which a temperature-controlled heat transfer fluid circulates. In the case of heating, energy in the form of heat is extracted from the surrounding soil via the primary circuit, causing the fluid to heat up. To raise the fluid temperature obtained in the primary circuit to the level required in the heating circuit of a building, a heat pump is needed. This is used to transfer energy in the form of heat from a low temperature level to a higher temperature level by supplying additional operating energy. The annual performance
factor expresses the ratio of the energy provided by the heat pump within one year to the required operating energy. For reasons of efficiency, an annual performance factor of at least 4 is aimed for, which can easily be achieved with energy sheet pile walls if they are properly designed.
Consequently, energy sheet pile walls provide a particularly efficient and economical system for the application in the primary circuit of a geothermal system. The thermal activation of sheet piles can thus make an effective contribution to the energy transition and to achieving international climate goals.
In the fields of geohydraulics, artificial ground freezing and shallow geothermal energy, ZAI has extensive knowledge and methodological expertise, gained by intensive research as well as by planning, consulting and expert activities. In this context, the capacity of thermally activated sheet piles was proven in large-scale tests by Prof. Ziegler and Dr. Koppmann within the framework of a research project at the Chair of Geotechnics in Civil Engineering of RWTH Aachen University, which is meanwhile completed. Moreover, in the same project, the practical feasibility of the systems was successfully confirmed by realizing pilot projects in Bergfelde (Brandenburg) and Feldberg (Mecklenburg-Vorpommern). About the results and calculation approaches for the dimensioning of such systems, Dr. Koppmann completed his doctoral thesis, which he finished with honors in the summer of 2021.
Installation of an energy sheet pile in Bergfelde (BB)
Shore stabilization by an energy sheet pile wall during
construction in Feldberg (MV)
In the Havelquartier Potsdam, six new building complexes are being constructed on a property adjacent to the Havel River with a total area of approx. 70,000 m². As part of the overall project, the first large-scale project using energy sheet piles in contact with an open water body is currently being realized in Germany. A total of 150 linear meters of new sheet pile wall on the Havel River will be thermally activated. In the further course of the project, the system will be used for heating and cooling of a new building block. ZAI was in charge of planning and dimensioning of the thermal activation in the work phases 2 to 7 of this project.
Installation of the energy sheet piles at Havelquartier Potsdam (© Y. Oldert)
View to the Havelquartier from the opposite shore (© Y. Oldert)
the service phases of design, approval and implementation planning. In particular, we benefit from our experience gained in research projects and previously realized construction projects, as well as from in-house developments in the field of design. In addition, we work closely with our cooperation partner and patent holder for the thermal activation of sheet piles, FET Future Energy Technologies PLC.
Let's shape the energy transition together
with thermal activation!
Koppmann, 2021. Dissertation.
Untersuchung der thermischen Aktivierung von Stahlspundwänden
Link zur PDF
Ziegler et. al., 2019. ECSMGE.
Energy sheet pile walls - Experimental and numerical investigation of innovative energy geostructures
Link zur PDF
Koppmann et. al., 2019:
Untersuchungen zum Einsatz thermisch aktivierter Spundwände als innovative Möglichkeit zur regenerativen Energiegewinnung. HTG-Kongress 2019, Lübeck 11.09 – 13.09.2019.
Koppmann et. al., 2018:
Experimentelle und numerische Untersuchung von Energiespundwänden. 35. Baugrundtagung, Vorträge: Geotechnik trifft Zukunft. Stuttgart 26. - 29.09.2018. DGGT, Deutsche Gesellschaft für Geotechnik e.V.. Seiten 305-312.
Our Cooperation Partner Future Energy Technologies PLC:
Energy sheet pile wall in the encyclopedia of geothermal energy: https://www.geothermie.de/bibliothek/lexikon-der-geothermie/e/energiespundwand.html