Geothermal Energy in Bavaria PROFILES PORTRAITS PERSPEKTIVES GLOBAL PARTNER The Geothermal-Alliance Bavaria: Research to strengthen the geothermal sector According to the Bundesverband of these Bavarian projects along- jects are successful, there is always Geothermie, 36 operational deep side projects, which are not used room for improvements in all geothermal projects are currently to produce power or heat, but for operative areas for this relatively located in Germany, of which two balneological purposes. Therefore young technology. are in the construction phase and 90% of thermal energy and 80% Since 2016, the Bavarian State five are purely utilized for re- of electrical energy generated in Ministry for Science and Art search purposes. In addition, 30 Germany is produced in Bavaria – funds the interdisciplinary re- projects are being planned. Of the a handsome sum. All the more search project “Geothermal-Alli- 36 projects, 26 are located in reason for the Bavarian govern- ance Bavaria” (GAB), which is Bavaria. This includes 22 opera- ment to unite and financially sup- being coordinated by the Munich tional projects, two planned pro- port the research of the deep geo- School of Engineering at the jects and two research projects thermal sector. Although the Technical University of Munich. [1]. Figure 1 shows the locations majority of deep geothermal pro- In total over 30 researchers from Fig. 1: Deep geothermal projects in Bavaria (blue: balneological use, red: district heating, green: district heating & balneology, yellow: district heating & power, grey: power). Source: Flechtner/TUM. The Geothermal-Alliance Bavaria The Geothermal-Alliance Bavaria Fig. 2: Research areas of the Geothermal-Alliance Bavaria. Source: Aubele & Flechtner/TUM. the Technical University of Understanding of interest. In this context, parti- Munich (TUM), the Friedrich- of the reservoir cularly worth mentioning is that Alexander-University Erlangen- The focus of this research field is for the first time a fiber optic Nürnberg (FAU) and the Univer- to characterize the Upper Jurassic cable is being installed in a deep sity Bayreuth work on solving aquifer system, which underlies geothermal borehole for research many different research questions the sediments of the South Ger- purposes, to further understand with the aim to improve the eco- man Molasse Basin as well as the process within the hydrother- nomic efficiency and minimize investigate the deep geothermal mal reservoir. Through constant the risks of deep geothermal pro- potential of the unexploited Nor- and depth dependent monitoring jects. This shall subsequently thern Bavaria region. In the mat- by means of fiber optics, one can improve the competitiveness and ter of the reservoir understanding, detect and record temperature- the acceptance of this local energy the research concentrates on and flow-zones within the aquifer source.The significant character- reliable predictions of flow rates as well as measuring shock waves. istic of this collaborative research and temperatures and the long- The latter is in particular signifi- project GAB is the comprehen- term behavior of an exploited cant for a better understanding of sive approach, combining all reservoir. Hereby it is not only the processes that could lead to aspects of a deep geothermal pro- important to make backed state- seismic events and their connec- ject, from the exploration and ments for the operational projects tion to deep geothermal projects. characterization of the reservoir but especially for projects in plan- Furthermore, work is being car- to the operation and monitoring ning. The hydraulic evaluation of ried out to analyze and further of the power or heat plant. The fault zones in comparison to the understand the stress regime of individual fields of research are mass facies regarding crucial para- the area, which can contribute to illustrated in Figure 2 and de- meters such as permeability and assess the risk of seismicity. A scribed in detail below. porosity is one of the core areas comprehensive seismic campaign The Geothermal-Alliance Bavaria Efficient and flexible power plants One of the main research fields within the GAB focuses on increa- sing the efficiency and flexibility of geothermal power plants aiming to improve profitability. The topics of thermodynamic optimization and flexibility of power-heat-cogenera- tion will be experimentally analyzed using a self-constructed 20 kWel Organic-Rankine-Cycle (ORC-) test rig (Figure 3) . Experiments regarding the evaluation of different Fig. 3: 20kWel ORC-test rig. Source: Eyerer/TUM. working fluids can also be carried out using the test rig. Alongside the is planned for Northern Bavaria, The goal is to reduce or stop the experimental approach, the opti- which will enable researchers to formation of scalings by looking at mization of the power plant will also get an insight into the deeper the plant set-up and adjusting the be worked on using simulations. underground and the existing operating strategy. Therefore re- Throughout the ongoing activities, a geothermal anomaly. earchers will and have undertaken study was published which estimated Thermal water cycle: extensive sampling campaigns at the potential of geothermal power scalings and existing boreholes, laboratory generation in Germany [3]. submersible pump analysis of the thermal water and The research fields regarding the geochemical modelling. In addition, Monitoring thermal water cycle focus on the a tool to predict malfunctions of The aim of this subproject is to operational problems caused by the submersible pump will be develop and validate a monitoring scalings as well as the technical developed, which can contribute tool for geothermal plants. The requirements of the submersible to optimize maintenance intervals monitoring tool will monitor pump. Many plants and pumps and therefore reduce costs regard- components within the plant and suffer under the high wear and ing this component. This will be help detect the formation of scal- tear caused by scalings. The GAB achieved by developing mathemati- ings. The detailed knowledge of will develop a prognostics-tool to cal models for the individual com- the processes within the plant optimize maintenance as well as ponents of the submersible pump. result in a higher availability of the better understand the kinetic for- Building on that, a suitable control plant and help optimize the plant mation conditions of the scalings. method will be developed [2]. efficiency. Ultimately, the re- Fig. 4: Position of the geothermal system within the energy system. By means of heat-power-cogeneration, the geothermal system can contribute to the power and heat production. Source: Aubele/TUM. The Geothermal-Alliance Bavaria search is aimed to improve eco- geology and petrology, rock Potential zur Stromerzeugung. nomic efficiencies of deep geo- mechanics, tectonic and stress field Geothermische Energie, thermal power plants. analysis, basics of drilling and pump- Heft 87, 2017/2, S. 26-27 ing technologies as well as power Geothermal energy engineering, business administrati- [4] Homepage der Friedrich- within the power grid on, public relations and mining and Alexander-Universität (2018): One particular challenge is the environmental law [4]. https://www.gzn.nat.fau.de/studium/ integration of the geothermal sec- im-studium/master-geothermiegeo- tor into the current energy Seedfunding energie/, system, which is increasingly The GAB has an allocated fund- Date: 07.05.2018 dominated by volatile renewable ing budget to support smaller energies. The GAB is trying to research projects, which relate to [5] Homepage der Geothermie- answer questions regarding the the ongoing research topics. The Allianz Bayern (2018): costs and potential of deep geo- funding is limited to Bavarian uni- https://www.mse.tum.de/gab/ thermal systems as well as evaluat- versities and distributed yearly forschung/seedfunding/, ing the contribution of deep geo- based on a selection process [5]. Date: 07.05.2018 thermal energy towards the ener- Communication, gy supply reliability. Deep geo- Networking and thermal energy can play a signifi- Information cant role for a greenhouse gas Next to completing the above neutral energy supply, especially mentioned research topics, the for urban areas. Figure 4 shows GAB poses as a communication how the geothermal system fits and networking platform for within the energy system of the stakeholders of the deep geother- future, which itself will rely less mal community. The GAB offers on fossil fuel supply. a unique point of contact for the All research carried out within the research community, to identify GAB can fall back on a growing and combine research questions, data pool, thanks to collaborations connect scientists, provide a with many Bavarian geothermal home for young scientists and plant operators. This clearly engage in concerns of operators shows the cooperative nature bet- and authorities. In addition, the ween research and industry. The GAB team provides information results of the scientific effort can for citizens and educational work be directly implemented and con- on the subject “deep geothermal tribute to strengthen this young energy” in a scientifically sound technology. and neutral way. Education, education, References education [1] Bundesverband Geothermie Of great importance for the GAB (2018): www.geothermie.de/ is the education of young re- fileadmin/useruploads/wissenswelt/ searchers in the field of deep geo- Projektliste_Tiefe_Geothermie_ thermal