TY - GEN A1 - Popovski, Eftim A1 - Ragwitz, Mario A1 - Brugger, Heike T1 - Decarbonization of district heating and deep retrofits of buildings as competing or synergetic strategies for the implementation of the efficiency first principle T2 - Smart Energy N2 - This paper discusses the compatibility of district heating (DH) networks with deep retrofits of buildings under various European climate conditions and city typologies. The study analyses five cities with different DH market shares, climate zones, population densities, and transferability potentials. First, we have forecasted population, heated floor area, and share of floor area per construction period until 2050, and then calculated three different heat demand scenarios for varying building refurbishment rates of 1%, 2%, and 3% of the total floor area. Second, future suitable DH regions with min 25 GWh/km2 networks were identified. By applying a bottom-up GIS model, based on the type of city area, number of buildings, street length, and heat density, the DH distribution capital and operation costs were calculated. Lastly, to compare the total cost of heat supply for each scenario, the cost of individual heat per building type was calculated. The results show that even in the scenarios with high refurbishment rates of 3%, high percentage of the built-up areas, between 23% and 68% depending on the city typology, are suitable for DH supply in 2050. The share of DH from the total heat supply varies between 49% and 83%. An increase of the DH price between 14% and 35%, depending on the scenario and case study can be expected due to the reduced heat densities compared to the current ones. Nevertheless, maximizing the DH connection rates in the identified regions leads to lower total cost of heat in almost all the analysed case studies. KW - Energy efficiency first principle KW - District heating networks KW - Bottom-up energy modelling KW - Geographic information system KW - Deep energy retrofit KW - Municipal heat planning Y1 - 2023 U6 - https://doi.org/10.1016/j.segy.2023.100096 SN - 2666-9552 VL - 10 ER - TY - GEN A1 - George, Jan Frederick A1 - Werner, Simon A1 - Preuß, Sabine A1 - Winkler, Jenny A1 - Held, Anne A1 - Ragwitz, Mario T1 - The landlord-tenant dilemma: Distributional effects of carbon prices, redistribution and building modernisation policies in the German heating transition T2 - Applied Energy N2 - A carbon price on heating fuels aims to reduce the use of fossil energy in the heating sector. However, it has a greater effect on tenants than on landlords. The heating transition requires adequate building insulation for efficient use of low-temperature technologies. To encourage this particular kind of investment, German landlords are given the option to apply a modernisation levy of up to 8% on top of rents. Similar to carbon pricing, rent increases cause distributional effects. The net effect of these measures on tenants has not been analysed so far. Using a micro-simulation integrating representative empirical data on tenant households in Germany from KOSMA and the detailed building database TABULA, we analyse direct distributional effects of a carbon price (€55/t and €250/t), a per-capita redistribution of carbon price revenues and the modernisation levy (8% and 2% rent increases). The analysis shows that carbon prices and modernisation levies have strong regressive effects. These can be mitigated by the per-capita redistribution. However, the effect on tenants within a given income decile varies largely due to the diversity of buildings. Thus, when designing and evaluating policies, looking at average effects is not sufficient to assess economic impacts for individual households. KW - Horizontal and vertical distributional effects of carbon prices KW - Energy-efficient building modernisation KW - User-investor dilemma KW - Micro-simulation Y1 - 2023 U6 - https://doi.org/10.1016/j.apenergy.2023.120783 SN - 0306-2619 VL - 339 SP - 1 EP - 11 ER - TY - GEN A1 - Billerbeck, Anna A1 - Breitschopf, Barbara A1 - Preuß, Sabine A1 - Winkler, Jenny A1 - Ragwitz, Mario A1 - Keles, Dogan T1 - Perception of district heating in Europe: A deep dive into influencing factors and the role of regulation T2 - Energy Policy N2 - To increase the deployment of district heating in line with European targets, there is a need to understand consumer perceptions and the role of regulations. Therefore, this paper focuses on consumer perceptions of district heating and analyses the influencing factors. The analysis uses data from an online survey with 4388 participants from nine European countries. In particular, the paper discusses the impact of socio-demographic factors, attitudes and regulations on the perception of district heating. Statistical analyses show that re-spondents from Denmark and Sweden have the most positive perception, while respondents from Lithuania and the Netherlands have a less positive perception of district heating. In addition, the results indicate that re-spondents from countries with no mandatory connection, liberalised price regulation and mainly public ownership seem to have a more positive perception of district heating, higher satisfaction when using district heating and a more positive rating of their heating price than those from countries with mandatory connection, regulated prices and a more mixed ownership structure. Overall, the paper provides a first overview of possible factors influencing the perception of district heating and indicates that the mix of appropriate regulations and, in particular, their combined impact, could play an important role in perception. KW - Consumer perception KW - District heating KW - Heating policy KW - Monopoly regulation KW - Social acceptance Y1 - 2024 U6 - https://doi.org/10.1016/j.enpol.2023.113860 SN - 0301-4215 VL - 184 SP - 1 EP - 17 ER - TY - GEN A1 - Sporleder, Maximilian A1 - Rath, Michael A1 - Xu, Yuwei A1 - Beek, Mathias van A1 - Ragwitz, Mario T1 - Utilizing Historical Operating Data to increase Accuracy for Optimal Seasonal Storage Integration and Planning T2 - 36th International Conference on Efficiency, Cost, Optimization, Simulation and Environmental Impact of Energy Systems (ECOS 2023), Las Palmas De Gran Canaria, Spain N2 - Policies reasoned by global climate change and increasing commodity prices due to the international energy crisis force district heating providers to transform their assets. Pit thermal energy storage combined with solar energy can improve this transformation process. Optimal energy planning of district heating systems is often achieved by applying a linear programming model due to its fast computing. Unfortunately, depicting those systems in linear programming requires complexity reduction. We introduce a method capable of designing and operating the system with the complexity increase of considering the top and bottom temperatures of the pit thermal energy storage in linear programming. Firstly, we extract and clean data from existing sites and simulations of seasonal storages. Secondly, we develop a polynomial regression model based on the extracted data to predict the top and bottom temperatures. Lastly, we develop a mixed-integer linear programming model using the predictions and compare it to existing sites. The model uses solar thermal energy, a pit thermal energy storage, and other units to meet the demand of a district heating system. The polynomial regression results show an accuracy of up to 92 % with only a few features to base the prediction. The optimization model can design the storage and depict the correlation between decreasing specific costs and thermal losses due to an increasing volume. The control strategy of the heat pump requires further improvement. KW - MILP KW - Seasonal Storage KW - Optimization KW - District Heating KW - Design Y1 - 2023 U6 - https://doi.org/10.52202/069564-0202 SP - 2241 EP - 2252 PB - ECOS ER - TY - GEN A1 - Popovski, Eftim A1 - Fleiter, Tobias A1 - Ragwitz, Mario T1 - The role of solar district heat in the energy transition of the German heating sector T2 - Energy N2 - This study explores the integration of solar district heating (SDH) into German heating networks, focusing on the energy transition in the heating sector. Utilizing energyPRO software, 8410 scenario variations were analysed, considering collector areas ranging from 1000 to 200 000 m2 and thermal storage capacities from 0 to 100 000 m³. The research identifies the most cost-effective SDH system designs, with solar fractions between 11 % and 18 % and collector area/storage ratios between 4 and 6.7, resulting in levelized costs of heat (LCOH) between 45 and 64 €/MWh. The techno-economic potential of SDH in Germany is estimated at 17.6 TWh by using a spatial analysis model. The paper presents sensitivity analyses and preliminary design equations, contributing to a comprehensive understanding of SDH's role in decarbonizing the heating sector. By integrating spatial data analysis with energy system modeling, the study offers a novel methodological approach, providing insights into the technical and economic feasibility of SDH systems in Northern Germany and similar climatic regions. The findings aim to assist policymakers and decision-makers in evaluating the costs and dimensions of SDH systems based on local heat demands and influencing economic and technical factors. Y1 - 2024 UR - https://www.sciencedirect.com/science/article/abs/pii/S0360544224029517?via%3Dihub VL - 310 PB - Elsevier ER - TY - GEN A1 - Ragwitz, Mario A1 - Billerbeck, Anna A1 - Bernath, Christiane A1 - Manz, Pia A1 - Deac, Gerda A1 - Held, Anne A1 - Winkler, Jenny A1 - Kök, Ali T1 - Integrating district heating potentials into European energy system modelling : an assessment of cost advantages of renewable and excess heat T2 - Smart Energy N2 - This paper takes a novel modelling approach by considering high spatial resolution heat generation potentials for district heating and integrating them into a European energy system model. Subsequently, a modelling analysis of an integrated energy system including district heating, electricity and hydrogen supply for 25 EU Member States and the year 2050 is carried out. In contrast to existing approaches, the modelling approach captures the heterogeneous resource availability in district heating. The results show multivalent district heating networks based on a wide range of renewable and excess heat sources used directly or in combination with large-scale heat pumps. The high spatial resolution of the heat generation potentials allows a detailed cost comparison of different possible future technology mixes in district heating. The paper finds that the use of heat pumps, geothermal energy and industrial excess heat offer slight cost advantages for the energy system as a whole. Geothermal heat can also provide cost advantages for district heating generation. Y1 - 2024 U6 - https://doi.org/10.1016/j.segy.2024.100150 VL - 15 SP - 1 EP - 13 PB - Elsevier ER - TY - GEN A1 - George, Jan Frederick A1 - Held, Anne A1 - Winkler, Jenny A1 - Eichhammer, Wolfgang A1 - Ragwitz, Mario T1 - Unveiling the cost competitiveness of sector coupling technologies : policy impacts on levelised costs of heat pumps and battery electric vehicles in Germany T2 - Smart Energy N2 - Heat pumps and battery electric vehicles play a crucial role in achieving a climate-neutral economy and integrating the Energy Efficiency First Principle into the building and transport sectors, rendering the overall energy system more efficient. To achieve cost competitiveness of these new technologies compared to conventional ones, investments, operating costs and conversion efficiencies are important. We conducted micro-simulations of the development of levelised cost of heat and transport for these sector coupling technologies to assess the direct cost impact of these parameters. With a broad and in-depth analysis of economies of scale, we determine future bandwidths of investment development. Based on this data, we compared implications of two policy scenarios of taxes and levies on final energy prices using a German case study. The first scenario considers recently adjusted taxes and levies: the national emissions trading system in 2021 and the abolishment of the electricity levy to finance renewable energy support in 2022. A counterfactual scenario includes previous framework conditions. Our results show that rising carbon and lower electricity prices already economically favour heat pumps from 2020 onwards. In contrast, taxes and levies do not decisively impact the cost competitiveness of battery electric vehicles, but expected reductions in manufacturing cost do. Y1 - 2024 U6 - https://doi.org/10.1016/j.segy.2024.100149 SN - 2666-9552 VL - 15 SP - 1 EP - 15 PB - Elsevier BV ER - TY - GEN A1 - Sporleder, Maximilian A1 - Rath, Michael A1 - Ragwitz, Mario T1 - Solar thermal vs. PV with a heat pump: a comparison of different charging technologies for seasonal storage systems in district heating networks T2 - Energy Conversion and Management: X N2 - Heat pumps and battery electric vehicles play a crucial role in achieving a climate-neutral economy and integrating the Energy Efficiency First Principle into the building and transport sectors, rendering the overall energy system more efficient. To achieve cost competitiveness of these new technologies compared to conventional ones, investments, operating costs and conversion efficiencies are important. We conducted micro-simulations of the development of levelised cost of heat and transport for these sector coupling technologies to assess the direct cost impact of these parameters. With a broad and in-depth analysis of economies of scale, we determine future bandwidths of investment development. Based on this data, we compared implications of two policy scenarios of taxes and levies on final energy prices using a German case study. The first scenario considers recently adjusted taxes and levies: the national emissions trading system in 2021 and the abolishment of the electricity levy to finance renewable energy support in 2022. A counterfactual scenario includes previous framework conditions. Our results show that rising carbon and lower electricity prices already economically favour heat pumps from 2020 onwards. In contrast, taxes and levies do not decisively impact the cost competitiveness of battery electric vehicles, but expected reductions in manufacturing cost do. KW - Sector coupling KW - MILP KW - District heating KW - Seasonal storage Y1 - 2024 U6 - https://doi.org/10.1016/j.ecmx.2024.100564 SN - 2590-1745 VL - 22 PB - Elsevier BV ER - TY - GEN A1 - Billerbeck, Anna A1 - Kiefer, Christoph P. A1 - Winkler, Jenny A1 - Bernath, Christiane A1 - Sensfuß, Frank A1 - Kranzl, Lukas A1 - Müller, Andreas A1 - Ragwitz, Mario T1 - The race between hydrogen and heat pumps for space and water heating: A model-based scenario analysis T2 - Energy Conversion and Management N2 - This paper analyses different levels and means of the electrification of space and hot water heating using an explorative modelling approach. The analysis provides guidance to the ongoing discussion on favourable pathways for heating buildings and the role of secondary energy carriers such as hydrogen or synthetic fuels. In total, 12 different scenarios were modelled with decarbonisation pathways until 2050, which cover all 27 member states of the European Union. Two highly detailed optimisation models were combined to cover the building stock and the upstream energy supply sector. The analysis shows that decarbonisation pathways for space and water heating based on large shares of heat pumps have at least 11% lower system costs in 2050 than pathways with large shares of hydrogen or synthetic fuels. This translates into system cost savings of around €70 bn. Heat pumps are cost-efficient in decentralised systems and in centralised district heating systems. Hence, heat pumps should be the favoured option to achieve a cost-optimal solution for heating buildings. Accordingly, the paper makes a novel and significant contribution to understanding suitable and cost-efficient decarbonisation pathways for space and hot water heating via electrification. The results of the paper can provide robust guidance for policymakers. KW - Hydrogen KW - Energy systems modelling KW - Optimization KW - Sector coupling KW - Heat pump KW - District heating Y1 - 2024 U6 - https://doi.org/10.1016/j.enconman.2023.117850 SN - 0196-8904 VL - 299 PB - Elsevier BV ER - TY - RPRT A1 - Koltzer, Nora A1 - Schoenherr, Johannes A1 - Sporleder, Maximilian A1 - Niederau, Jan A1 - Ragwitz, Mario T1 - Repurposing idle wells in the North German Basin as deep borehole heat exchangers T2 - Geothermal Energy N2 - This study investigates the feasibility to repurpose wells from gas production for geothermal closed-loop application in the North German Basin (NGB). The objective for this research topic is to extend the value-added chain of idle wells by re-completion as coaxial deep borehole heat exchangers as an efficient way to produce green energy without drilling new wells by saving the carbon emission and costs of building a new geothermal well. With numerical models of two typical geological settings of the NGB and two different completion schemes, it is possible to simulate the thermal performance over a lifetime of 30 years. The calculated heat extraction rates range from 200 to 400 kW, with maximum values of up to 600 kW. Sensitivity analyses demonstrate that re-completion depth and injection temperature are the most sensitive parameters of thermal output determination. The heat demand around the boreholes is mapped, and heat generation costs are calculated with heating network simulations. The initial production costs for heat are comparable to other renewable energy resources like biomass and competitive against gas prices in 2022. This study highlights available geothermal resources’ environmental and economic potential in already installed wells. The application has almost no geological and no drilling risks and may be installed at any idle well location. KW - North German Basin KW - Deep borehole heat exchanger KW - Legacy wells KW - Heat generation costs KW - Vacuum insulated tubing Y1 - 2024 U6 - https://doi.org/10.1186/s40517-024-00315-4 VL - 12 (2024) ER -