Expert Opinion on the Added Value of Interconnectors in the Use of Deep Geothermal Energy
EXPLOITATION OPTIMIZATION OF THE GEOTHERMAL POTENTIAL
The research team of the joint-project Geothermal-Alliance Bavaria has evaluated the potential of deep geothermal use through interconnected pipelines in a report for the Bavarian State Ministry for Economic Affairs, Energy and Regional Development. According to their findings, the potential of the large-scale transport of district heating can be optimally used from a techno-economic point of view and thus offers an opportunity to save large amounts of CO2 in the heat supply. A summary of the results can be found in the current issue of Geothermal Energy ( link ).
Over the past fifteen years, Bavaria has become a hotspot for deep geothermal utilization in Europe. There are now 23 plants operating in the Molasse Basin which provide climate-friendly heat, power and cooling. For example, the state capital plans to cover its district heating supply in a climate-neutral manner and largely from deep geothermal energy by 2040. However, the use of deep geothermal energy is not limited to Munich.
High potential in southern Bavaria
The demand for space heating and hot water calculated in this study is just under 160 TWh. A total of 99 areas were identified where district heating is a potential supply technology. These areas correspond to almost 50% of the total heat demand in Bavaria. According to the estimates, the deep geothermal potential in the Molasse Basin alone could supply 80% of the district heating demand (7655 MWth). To raise the enormous potential, theoretically about 500 doublets, i.e. production and injection wells, would be necessary.
Forecasts for drilling succes – is there enough hot water?
The success of further geothermal wells, and thus the basic prerequisite for the economic success of deep geothermal energy, can be predicted comparatively well for the Molasse Basin. However, there are significant local differences in terms of predictability. Comparatively good forecasts for drilling success are given in particular in Munich, south of Munich and in the eastern Molasse, where there is already a comparatively high number of successful wells today.
Optimal utilization of the resource
Geothermal energy shows its strengths particularly in the base load supply. The prerequisite for operating a deep geothermal system economically is that the heat can be drawn off to a sufficient extent via a district heating network. In many parts of the Molasse Basin there are particularly favorable geothermal conditions, which, however, do not coincide directly with the heat consumers on the surface. In these cases, there is the possibility of transporting the heat to the consumers via interconnection lines and thus optimally exploiting the potential. The construction of larger interconnecting pipelines increases the amount of geothermal energy that is extracted and consequently also its share in the heat supply – the number of systems required is minimised. If hydrocarbon based energies are pushed out of the heating network, large amounts of CO2 savings – With base load covered by deep geothermal energy, around two million tons per year. The analyzes show that the interconnection pipelines can also have a positive effect on the heat generation costs and increase the reliability of systems.
High investment costs – an obstacle
The implementation of a deep geothermal project involves high investment costs. These costs are further increased by the construction of larger interconnectors. However, for interconnection pipelines across municipalities to transport green district heating to neighboring municipalities and beyond, there are currently no equivalent funding mechanisms available as there are for on-site heat production. The technology will become economically attractive for municipalities or investors when the initial costs, especially for drilling, network expansion or interconnectors, become lower and get public support.
The study will be published in the coming weeks by the Bavarian State Ministry for Economic Affairs, Energy and Regional Development.
Contact: Dr. Maximilian Keim; Tel.: +49 (89) 289 – 10641; firstname.lastname@example.org