DTU is not only in the lead, when it comes to technical and natural science. DTU concurrently houses 10.000 students and 5.000 employees, who everyday work within most engineering disciplines. Research and education to this extent and high level, require not only a lot of square meters and experimental facilities, but also an extensive amount of energy.
At the DTU campus in Lyngby the energy consumption for cooling processors and rooms, as well as cooling the collected computer force and datacentres, pose as a significant part of the energy score. Due to this DTU continuously search for sustainable solutions capable of reducing the environmental strain, promote green technologies, and simultaneously have a positive influence to the profit and loss account.
In the case of DTU campus Lyngby, a possible solution was close by. As it happens, DTU Risø, located in close proximity to Roskilde Fjord, has for several years successfully used groundwater as an energy source for cooling. The use of groundwater is a technical solution, able to supply an extensive amount of cooling, with a low energy consumption. The key issue was to determine, if a similar solution was even possible at DTU Lyngby, with the knowledge of the grounds being in close proximity of drinking water aquifers, as well as already known groundwater contamination.
Sustainable, secure, invisible and soundless
In order to investigate the hydrogeological opportunities for installing groundwater cooling at DTU Lyngby, DTU Campus Service and Geo entered a collaboration. The purpose of the collaboration includes an assessment of the potential of groundwater cooling for DTU Lyngby. The aim for the project is in the future to be able to substitute a substantial amount of the traditional cooling machines and cooling aids with a sustainable solution, which excels by taking up very little room, is reliable, possible to integrate to the surrounding environment and at the same time noiseless. In other words, a system which summer and winter is capable of supplying sufficient cooling in order to ensure lightning fast computer calculations and provide the optimal conditions for the advanced testing facilities, important to DTU.
ATES stores energy in the underground for cooling and heating of buildings. A small system can easily produce an amount of energy equal to the annual energy consumption of 300 low-energy houses.
Did you know that a deep concrete basement construction will float on top of the groundwater table just like a ship, if the dewatering fails? We handle the design, installation, operation and maintenance of the largest and most advanced groundwater controlling systems in Denmark.
Did you know that the Danish underground is rich on energy sources besides fossil fuels? In Geo, we help our clients use groundwater as an energy source, by designing and delivering groundwater based geoenergy systems for industrial and commercial cooling, and for heating of buildings.
During a dewatering project Geo manages from 10 m3 to 30.000 m3 of groundwater per week. The latter is equivalent to the amount of water needed to fill 12 Olympic pools.
If 1 litre of the cleaning fluid PCE, formerly used by dry cleaners, winds up in the groundwater, it could contaminate 1 million m3 of groundwater. This is equivalent to 1 family’s water consumption for 6.500 years.
Ahead of the project, Geo scrutinised all available data, in order to estimate the likeliness of a positive outcome of investing in a deep groundwater exploration/ test well. Even though the Danish geology is inhomogeneous, the probability of a high-efficient and extensive groundwater resource present at some 60-80 metres below the surface was evident. Furthermore, the possibility of another aquifer deeper in the chalk approximately 100 metres below the surface was also present – this was however undocumented and uncertain.
As consultant and drilling entrepreneur, Geo’s next role in the project was to obtain the necessary authorisations for a deep well. The purpose of the well was to determine in detail the hydrogeological setting of the area, using geophysical methods and pumping tests to determine the physical and hydraulic properties of the soil layers, in order to ensure a strong data foundation for the subsequent work.
The test well, drilled in the spring of 2014, was a screened well going down to 110 metres below the surface. The large dimension of the well allows for future use in a system for cooling production.
The well uncovered the expected aquifer approximately 60 metres below the surface, as well as an unexpected deep-lying aquifer in the chalk some 90-100 metres below the surface. This find widens the opportunities for the installation for groundwater-based energy, as well as the opportunity of optimising the facility, in relation to other interests in the area.
The ongoing work during the summer of 2014 includes carrying out long-term test pumping to determine the range and capacity of the aquifer. Based on the new data and the existing data from the area, Geo establish a 3D geological model of the surface, as well as a numerical flow model. The models may be applied in the calculations of the hydraulic and thermal influences from abstracting cold water for cooling and reinfiltrating heated water, which is lead back to the aquifer for storage.
With the model fully updated and calibrated, DTU will later on be able to simulate various system configurations, in case DTU wants to continue the work with the groundwater-based solution as a part of DTU’s sustainable energy supply.