Geothermal Energy Supply of the New Building of the Fire Station in Dortmund Hörde
Prof. Dr. Rolf Bracke
Dipl.-Geophys. Gregor Bussmann
Dipl.-Geol. Sabine Neulen
Dipl.-Ing. (FH) Katja Winkler
Stadt Dortmund - Städtische Immobilienwirtschaft / Energiemanagement
The city of Dortmund and the civic real estate industry plan the construction of the new fire station 4 in Dortmund-Hörde.
In order to meet the new requirements of an environmental sound and economic energy supply of the station the GeothermalCenter conducted a feasibility study of a geothermal energy supply system.
Due to the distinctive utilisations of different parts of the projected station various energy demand profiles are present. There are a range of variations a geothermal heat and cool supply can be realised. By combining geothermal wells with different depths an adjusted supply of energy from the ground to the building according to the relevant demand profiles and required temperatures is granted.
One possibility to utilise the geothermal potential at this site of the new fire station is given by a closed subsurface heat exchanging system with various depths. Taken from the stone the geothermal energy is transported to a heat pump where it is raised to an adequate level of temperature. Space heating is as well as water heating the aim of the geothermal approach. The required power to run the heat pump can be delivered either by electrical input or by natural gas. In the case of rather low demand profiles the geothermal medium taken from the wells might be used without the support of a heat pump.
In the first phase of the study a simplified modelling of the geothermal system is conducted in order to achieve an idea of the system’s dimensions and the feasibility of a geothermal energy supply concept. The aim is to deliver information for further planning processes.
The feasibility study therefore deals with:
- the determination of the frame conditions for the supply technological feasibility,
- the gathering of the heating and cooling demand in relation to the time of operation,
- the appraisal of the geo-scientific properties of the site
- the modelling and caclucation of the geothermal energy potential
- the determination and design of a technological system for energy extraction and distribution
The conduction of the study is subdivided into to distinctive phases:
The first phase is a conception phase which is considered to be a basic feasibility study with the aim to deliver information for a detailed planning of the geothermal energy supply. The findings of the first phase’s endeavours are already present in a report.
The second phase is considered to be the design phase. A detailed dimensioning of the plant is in its focus.
In the feasibility study geothermal extraction rates have been simulated for near surface systems with depths of 250 m and for two deep geothermal plants with depths of 500 m and 1,000 m.
These simulations have been based on the investigated geological profiles and on the demand parameters the city of Dortmund supplied for a similar fire station which was built in Dortmund-Eichlinghofen in October 2004.
Due to different demand in different parts of the station a combination of various technological approaches have been chosen so that demand peaks can be compensated.
Based on the geological conditions feasibility of a geothermal energy supply of the fire station 4 in the technological sense has been demonstrated.