GeothermieZentrumBochum e.V. (GZB)
The companies given below, hold competences in the planning, the realisation and the operation of geothermal energy systems. These companies have proven by an evaluation process (application form below) adequate practical experiences in their fields of competences mentioned here.
The adjoining diagram reproduces the geothermal heat flux density in Europe. It was taken from the “Atlas of Geothermal Resources in Europe” (European Communities, 2002) and a sectional drawing of the earth was superposed. The heat flux density is a physical dimension to quantitatively describe heat transferring processes. It is defined as the amount of heat flow that is exchanged across a unit area of a system, e.g. the amount of geothermal heat conducting to the earth’s surface. It can also be described as heat flow per area A.
The colours of the diagram indicate different geothermal potentials:
red = excellent potential
orange = very high potential
yellow = medium to high potential
green = moderate potential
blue = low potential
[Hurter, 2002] Hurter S., Hänel R.: Atlas of Geothermal Resources in Europe, Luxembourg: Office for publications of the European Communities, 2002 Visit the adjoining homepages of the Geothermalcenter Bochum.
The adjective geothermal is a combination of the Greek “geo” = earth and “therme” = heat and stands for the heat taken from the earth.
- Definition according to VDI 1998: (translated from the original German version)
- Geothermal energy is energy stored as heat under the solid surface of the earth.
The overall amount of geothermal energy is made up in range of 30 percents by residual heat. Kinetic energy from the agglomeration of matter 5 billion years ago, when the planet was created, was stored as heat energy within the rocky mass of the earth. Due to the low heat conductivity still today residual heat from this genesis process is present under the earth’s surface.
Approximately 70 % of the geothermal energy is supplied by the radioactive decay of the isotopes potassium 40, uranium 235, uranium 238 and thorium 232. This process continuously generates heat that is stored in the rocks.
Close to the earth’s surface the mean temperature is 10°C (50°F) and increases towards the core by 3°C (37.4°F) each 100 meters.
As the residual heat and the heat from decay process are finite, geothermal energy is not a renewable energy. However, its potential will prospectively ensure reliable energy supply for the next millions of years. Therefore geothermal energy can be considered to be a renewable energy on the human scale.
The essential advantage of energy taken from the earth’s inside in comparison to other renewable energies is its ability to supply baseload energy. Geothermal heat is unaffected by daily, seasonal and annual changes and therefore constantly and consistently available. It can be extracted from its subsurface reservoir by various proven technologies. As virtually no carbon is emitted by using geothermal energy it is regarded to be outstandingly climate friendly. The proportion of extracted primary energy to useful heat is very advantageous.
The GeothermalCenter ist made and supported by:
- the 'GZB-Trägerverein - gemeinnützige wissenschaftliche Körperschaft e.V.'; with the supporting universities RWTH Aachen, University of Applied Sciences Bochum, University of Applied Sciences Gelsenkirchen and the University of Applied Sciences Ostwestfalen-Lippe and further public organisations (EnergieAgentur NRW, District Government Arnsberg, City of Bochum and the Chamber of Commerce and Industry) as well as
- the 'GZB-Wirtschaftsvereinigung e.V.'; consisting of companies from the construction, energy, montan industry, communal supply, plant construction, building services, handcrafts and expert planning.
The GZB is pursuing following objectives:
- to transfer technology, know-how and information between universities, economy and the public,
- to conduct and to foster application-oriented geo-research between various universities and the economy; to install a “close to economy” research establishment based on the GZB for the foundation and/or the evolution of technology-oriented businesses,
- to supply education and advanced training to engineers, geo-scientists, miners, architects and craftsmen in terms of heat mining and its integration into the structures of buildings and infrastructural systems,
- to retrain employees of the mining industry in future energy technologies (“from coal mining – to heat mining”),
- establishment of a scientific network of associated universities and research bodies on the national and international scale,
- to increase the recognition of geothermal energy within North Rhine-Westphalia and beyond; and to institute an information service for contractors, planner and interested parties.