EP8 - Economic Utilization (JENA-GEOS®)


Aims

Besides as basic research, research shall serve in particularly as a resolution for social challenges. Especially geoscience can be a decisive contributor to the questioning of climate change, the resulting energy evolution in Germany and the basic issues of general interest, for instance in terms of water supply. In context of the INFLUINS joint research project JENA-GEOS® orients towards the questioning, which is referring to the energy evolution. With the results of EP8, JENA-GEOS® will add an essential contribution to the success of the joint research project INFLUINS and help to implement a technological and ecological advantage, which will prospectively generate a technology transfer on national and international stage.

Working area

In this context, EP8 deals with the scientific reuse of energetic geo potential of the Thuringian Basin. Initial application area is the utilization of deep geothermal energy systems as a base-loadable, renewable energy. Because of specific project development of geothermal energy systems in the Free State of Thuringia, the considered area was extended to south Thuringia. In conclusion of the current debate referring to the progression of the energy revolution and the foreseeable upheavals dealing with legal and financial framework of funding of renewable energies (Amendment of EEG-feed-in compensation ,introduction of storage facilities in frame of uniform energy law, modification of market design in the energy market), a continuative thesis was developed in which underground storage facilities store "green" hydrogen and synthesis-methane for improvement of the base-load capability of renewable energies. Another point of emphasis of EP8 is the ecological reuse of the experimental drillings in Erfurt.

Methods

For some time JENA-GEOS®-Ingenieurbüro GmbH deals i.a. with several research- and development-projects (FuE) for sustainability in the field of geo science. These include several collaborative projects in context of sustainability research as well as research in the field of geothermics and the evaluation of geo-risks. The identification, acquisition and evaluation of geo potential as well as its monetization represent central methods of operation. The cooperation and consultation with the other individual projects are important elements to acquire the pre-set goals of EP8. Furthermore the evaluation of drilling data, geological profile, thermal profile and old reports are a central field, to determine the potential of deep geothermics. Concerning this JENA-GEOS® cooperates with different project partners dealing with continuative research projects such as OPTIRISK.

Results

A.) Attendance at the project development deep geothermics Thuringia

Referring to the ecological use options of deep geothermics in Thuringia, major knowledge was acquired. At a site in Erfurt no ecological useable hydrothermal reservoir could be detected, which could be used for an economic business of power production. But it is possible to use the brittle and buoyant crystalline rock of the basement of the Thuringian Basin as a reservoir by petrothermal development technology. The petrothermal reservoir horizon at the site in Erfurt consists of migmatite of the central German crystalline zone. At reservoir sinking of 5.500m underneath the ground surface it can be expected to have an adequate temperature level, to enable an economic plant operation with the current available technology. Questions dealing with petrothermal development concepts are processed in scientific follow-up projects.

Although the evaluation of chances and risks of deep geothermics in Thuringia show, that the implementation of demonstration projects especially in south Thuringia have an excellent perspective, the poor public acceptance reveals that questions of risk assessment in matters of seismicity, fracture propagation or hydrogeological-chemical interaction as well as the communication of the INFLUINS-Network offer important connection factors.

B.) "Improvement of base-load capacity for renewable energies by underground-gas-storages" - Evaluation of exploitation potential

Thuringia has numerous potential gas storage structures of various volume and primary gas fillings (dismantled gas fields, not dismantled lean gas deposits). Natural gas is already stored seasonal and demand-based for decades by using individual storage structures in the Thuringian Basin.

  • The density and quality of the available energy infrastructure make Thuringia an excellent site for the realization of new power supply concepts.
  • Germany's central location in middle Europe does not only make the Free State to a transit country for roads, but also for gas pipelines and high (very high) voltage lines. Thuringia has a dense electricity and gas network. • In the central area of Thuringia are a majority of the renewable energy plants (photovoltaic, wind power, biomass) located.
  • Within the Thuringian Basin, numerous geological structures for the storage of gases have been detected. Some of the storage structures are located at discharged gas deposits with arch and anticline structures including suitable reservoir rock.
  • Some of the structures have been already used as storages after their exploitation or can be used as storages after minor effort.
  • The currently explored storage volume in Thuringia is estimated to have a volume of ca. 5 Bio. m3. The several storage volume vary from 50 Mio. - 3 Bio. m3.
  • Some of the Thuringian structures are filled with lean gas - a mixture of methane and carbon dioxide - which has an extraordinary significance for the methane synthesis.
  • The storages are suitable as operating storages for gas components (H2 and CO2) as well as prepared and useable, natural gas storages.

The Thuringian Basin features favorable characteristics for the PGP-Technology (Power-Gas-Power). In addition to the developed gas and energy economy, the Thuringian Basin features several underground gas storage potentials, which are particularly suitable for the PGP-Technology.

Common reservoir rocks in Thuringia can be found in the

  • Sandstone of the upper Carboniferous/Rotliegend formation (poricidal storage),
  • Carbonate rock of the Permian (ravine and porocidal storage) and
  • Sandstone of the middle layer of the variegated Sandstone (poricidal storage).

Requirements of a reservoir rock are an amount of over 10% of interconnected pores and effectively coverage and limitation of damming layer sequences, which prevent a diffusion of gas in other stone layers and the surface.

Two natural gas storages in exploited gas deposits are still run today in the Thuringian Basin. The INFLUINS-Network is due to its methodical competence particularly suitable, for one thing in matters of structure explanation methods, for another thing in matters of interaction of examination processes, in frame of the abovementioned scientific and economic attachments further processed. Furthermore the outstanding regional-geological knowledge in connection with current results about the expansion and development of the Thuringian depression will make its contribution For the expansion of the underground storage in connection with Power-to-Gas-to-Power Technology it is worth to make further effort. Furthermore Thuringia's potential could be used in an industrial-scale installation to store energy of nearby German Federal States.

C.) Profitability review for the reuse of the exploratory drilling EF 1/12 with deep geothermal probes

Beginning in 2015, on the basics of the planed continuative research program a scientific reuse of the INFLUINS drilling in Erfurt is favored. Furthermore it is possible to use deep borehole heat exchanger for an economic utilization of the drilling when the scientific reuse is terminated. First economic analysis show, that launching projects and further observation regarding this could be highly profitable.

Team

Members of the Team EP8 you will find here.