GRC Transactions, Vol. 38, 2014 Development of Geothermal District Heating in Germany Eckehard Büscher, IGO International Geothermal Centre, Bochum, Germany [email protected] Keywords permit. As the use of local heat is the fundamental idea behind Green district heating, deep geothermal energy, renewable modern district heating systems DH becomes more and more heating and cooling, Germany relevant. Heat, cold and fuel sources that normally would be lost, remain in the local systems for both: the residential as well for the non-residential sector including industries. Another important ABSTRacT aspect is the political target to become more and more independent from external gas and oil resources. The heating and cooling sector plays an important role with In Germany in April 2014 27 deep geothermal projects are respect to the primary energy demand, as in the EU and all over operational, 10 are under construction and more than 30 are in the world heat and cold demand accounts for about 50% of the the planning phase [Table 1]. All the operational projects are final energy consumption. The potential of geothermal energy providing heat, seven of them producing electricity as well. These for this sector and not just for electricity supply is vast: the RHC figures show a strong and rising interest in GDH in Germany. (Renewable heating and cooling panel – European Technology This projected development has the advantage, that geothermal Platform) estimates in 2020 over 25% of heat consumed in the EU district heating are efficient ways concerning costs, and that could be generated with renewable energy. By 2030 RHC technolo- Table 1. Actual Deep Geothermal Projects in Germany. gies could supply over the half of the heat used in EU-Europe. Be- sides geothermal energy, biomass and solar power are the basis of RHC. One of the reasons for an optimistic look into a renewable future in Germany is the increas- ing use of highly effective district heating systems with geothermal energy as base load. Current State In Germany the existing dis- trict heating systems mostly use conventional fossil fuels. They have been in operation for cen- turies. But coal mining has to be stopped in Germany until 2018 due to European laws. Some operators of heat plants and combined heat and power plants will get difficul- ties in extending their operating 197 Büscher Table 2. CO2-emissions of different Heating sources. Project Example: Green District Heating of the City of Munich The city of Munich with more than 2 million inhabitants has ambitious targets on its future energy supply: Munich wants to become the first CO2-free capital of the world. 100% of the elec- tricity should be produced from renewable sources until 2025. Munich wants to generate 100% of its heat demand on renewable energies with biomass and geothermal energy until 2040 [Fig.1]. In many cities all around Munich i.e. Ismaning, Kirchweidach, Sauerlach about 3,000m deep holes are drilled to contribute to the they are systems with the smallest emission of CO2 [Table 2]. Furthermore geothermal energy is an inexhaustible heat source which has a high security of supply for it is not affected by outside temperature, season or time of day and can be installed in every European state [Table3]. Table 3. Number of GDH in Europe in 2012 and 2015 [4]. Figure 2. Geothermal Heatplant in Munich-Riem [1]. heat supply via a district heating system (Fig.2-4). Besides to the construction of new DH-systems the con- version from existing district systems with temperatures of more than 100°C to new systems with lower tempera- tures is one of the challenges Germany´s heat market has to solve. [Fig.5] Future Development in Europe and Germany The first phase of the German Energiewende focused on renewable electricity. Meanwhile more than 25% of German electricity is produced mainly by wind and photovoltaic and the phase-out of nuclear power will be managed without power cuts; in contrast Germany is still exporting electricity. Now it’s Figure 3. Geothermal Power- and Heatplant in Sauerlach near Munich [2]. the time to concentrate on a sustainable development on the heat market, which is good for more than 50% of energy consumption Figure 1. Development of Green District heating in Munich/Germany [4]. (electricity just 16% [5]). 198 Büscher This projected development uses the advantage, that geothermal district heating is efficient concerning costs and environ- mental impact by producing the smallest emission of CO2. Furthermore geothermal energy is an inexhaustible heat source which has a high security of supply for it is not affected by outside temperature, season or time of day and can be installed in nearly every (European) state. Another aspect is the urbanization taking place all over the world. In future more and more people need heating and cooling in highly populated urban areas. Geothermal energy will heat and cool their homes, offices and factories in an effective and sustainable matter. For 2015 27 of the 33 European countries are expected to be equipped with geothermal district heating systems. In this short interval especially the number of systems in Germany and France with the lighthouse projects in Munich and Paris is expected to increase. Figure 4. Functional Chart of one of the Munich Geothermal Heating Systems [2]. References [1] GtV - German Geothermal Association, http:// www.geothermie.de/wissenswelt/geothermie/ in-deutschland.html [2] Geothermie-Heizkraftwerk Sauerlach“, Mit- teilungsblatt des GtV Geothermische Energie, No. 79, Christian Pletl, May 2014 [3] Büscher/Knutzen, Geothermische Fernwärme in Deutschland, BEE-Forum, Hannover Fair 8th April 2014 [4] EGEC Market report 2013 [5] Sandrock, Hamburg Institut, Potentiale der Fernwärme für die Energiewende, Düsseldorf 27.03.2014 Figure 5. Potential (Geothermal) District Heating Areas in the “Ruhr area” (6 million inhabitants) [3]. 199 200.