Exploratory drilling in the deep subsurface
On Monday the GFZ German Research Centre for Geosciences started research drilling on the campus of the Technical University of Berlin in Charlottenburg. The data collected is intended to clarify whether Berlin’s substratum is suitable for storing heating and cooling energy. The study is being accompanied by extensive wellbore measurements and laboratory tests.
Porous, water-bearing rock strata called aquifers offer considerable potential for the seasonal storage of heating or cooling energy. In summer heat can be stored in these deep rock formations in order to be then used in winter for heating. Ernst Huenges, Head of Geothermal Energy Systems at the GFZ and professor at the Technical University of Berlin: “Berlin's heat supply is currently almost entirely based on fossil fuels. The seasonal heat storage in the ground has considerable potential for providing cities such as Berlin with domestic energy.” Project manager Dr Ali Saadat from GFZ adds: “When considering future energy supply concepts for districts such as the TU Berlin’s campus, aquifer storage systems are indispensable. With reliable usage concepts, we want to contribute to the development of this environmentally friendly technology.”
There has previously been very little data available about Berlin’s deep subsurface. The results of the drilling and the accompanying field and laboratory investigations will significantly improve the geological knowledge about the structure of Berlin’s deep subsurface. The exploration well is being drilled as a vertical well to a depth of around 530 metres, i.e. considerably below the potable water layers. For the scientific investigations, rock samples and borehole cores up to 100 metres long are being removed, which are being examined on the spot and in GFZ’s specialist laboratories.
Seasonal energy storage in aquifers
Aquifer storage systems utilise the ability of the groundwater and water-bearing rock to store thermal energy, whereby both heat and cooling energy can be stored. The storage capacity of aquifers is large compared with other thermal storage systems, since a large thermal mass is available. For this reason, aquifer storage systems are usually used as seasonal or long-term storage systems.
The drilling forms part of a joint research project between GFZ, TU Berlin and the University of Arts Berlin (UdK). In this project, knowledge from the specialist energy technology, geochemistry, geology, architecture and urban development disciplines are being combined to develop seasonal storage concepts for supplying heat to neighbourhoods and building complexes. Seasonal heating and cooling storage systems beneath the Platz der Republik have already been supplying Berlin’s parliamentary buildings since the year 2000.
The project summary provides further details on the “AquiferCampus Berlin” research project.