Experimental investigation of sustainable and energy efficient management of a geothermal field as a heat source and heat sink for a large office building
The new construction of a large office building in Hamburg, which is the subject of this investigation, has been closely monitored over a period of about 5 years. In addition to evaluating and optimising the energy demands and user comfort, the focus was on the management of the energy from an exceptionally large geothermal field which is used for heating and cooling the building. The possibilities for sustainable, energy efficient use of the geothermal field were investigated. The basis for the evaluations is a fibre optic Distributed Temperature Sensing (DTS) system, by means of which temperature profiles in the ground as well as in the concrete of the energy piles are recorded on an ongoing basis. With regard to the impact of geothermal energy use on the environment, the surrounding soil may be considered as undisturbed to date, based on the corresponding ground temperature measurements. The ground temperature measure-ments within the geothermal field show that by carrying out manual operating adjustments, ultimately the original soil temperature level could be achieved once again, after the three operating years under examination. A long-term, sustainable and therefore energy efficient use of the geothermal field is thus fundamentally possible in the present case.
