In the article from ‘Civiele Techniek’ 2022, issue 7, steel sheet piles as a sustainable energy source are further explained. This is a part of the article from “Civiele Techniek’ issue 7 about the Energy Sheet Pile
“Energy Sheet Pile: Steel Sheet Pile as an Infinite Energy Source”
The fact that the Netherlands is transitioning to sustainable energy sources for our built environment in the foreseeable future requires no further explanation. The subsurface is frequently used as a source of sustainable heat through open and closed WKO sources. (Heat cold storage) However, foundation elements in the subsurface can also function effectively as an energy source, for example, by activating foundation piles, tunnels, and walls to extract or store thermal energy. Recent trials and various projects have demonstrated that the Energy Sheet Pile is a viable energy concept ready to be implemented as a sustainable heat source.
Operation of the Energy Sheet Pile
The Energy Sheet Pile is a newly patented system in which the steel sheet pile construction, in addition to its role as a ground and water barrier, serves as a heat exchanger for extracting thermal energy from surface water (aquathermy) and the shallow subsurface. The system consists of activation loops that are attached to the ground side of the steel sheet pile before installation. The sheet pile can be thermally activated at any desired level. An already installed sheet pile can also be activated by installing a retrofit front panel (protected activation loops) on the water side of the sheet pile. A fluid (refrigerant, glycol) is pumped through these activation loops, turning the sheet pile into a heat exchanger. The fluid in these activation loops extracts heat from both the surface water and the ground.
This is a completely closed system; no water is withdrawn from the canal and only the thermal energy surrounding the sheet pile is harnessed. Because the water in waterways is always (slightly) in motion, highly efficient heat transfer is achieved.
In addition to the practical test in De Zweth, several projects have already been realized in the Netherlands and Germany. The first practical application is in the Enkhuizen marina, where Energy Sheet Piles are used to heat the marina building. Furthermore, Energy Sheet Piles have recently been installed at It Swettehûs in Leeuwarden, a fully circular operating building in the province of Fryslân. In Germany, Energy Sheet Piles are active in two locations, and recently, in Potsdam, over 100 meters of quay were equipped with Energy Sheet Piles for a new construction site. At the time of writing, various feasibility and design projects are underway to implement the Energy Sheet Pile, and the system has already won several awards, including the NENnovation Award 2020 and the Water Innovation Award 2021.
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