@misc{PopovskiRagwitzBrugger, author = {Popovski, Eftim and Ragwitz, Mario and Brugger, Heike}, title = {Decarbonization of district heating and deep retrofits of buildings as competing or synergetic strategies for the implementation of the efficiency first principle}, series = {Smart Energy}, volume = {10}, journal = {Smart Energy}, issn = {2666-9552}, doi = {10.1016/j.segy.2023.100096}, abstract = {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.}, language = {en} } @misc{GeorgeWernerPreussetal., author = {George, Jan Frederick and Werner, Simon and Preuß, Sabine and Winkler, Jenny and Held, Anne and Ragwitz, Mario}, title = {The landlord-tenant dilemma: Distributional effects of carbon prices, redistribution and building modernisation policies in the German heating transition}, series = {Applied Energy}, volume = {339}, journal = {Applied Energy}, issn = {0306-2619}, doi = {10.1016/j.apenergy.2023.120783}, pages = {1 -- 11}, abstract = {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.}, language = {en} } @misc{BillerbeckBreitschopfPreussetal., author = {Billerbeck, Anna and Breitschopf, Barbara and Preuß, Sabine and Winkler, Jenny and Ragwitz, Mario and Keles, Dogan}, title = {Perception of district heating in Europe: A deep dive into influencing factors and the role of regulation}, series = {Energy Policy}, volume = {184}, journal = {Energy Policy}, issn = {0301-4215}, doi = {10.1016/j.enpol.2023.113860}, pages = {1 -- 17}, abstract = {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.}, language = {en} } @misc{SporlederRathXuetal., author = {Sporleder, Maximilian and Rath, Michael and Xu, Yuwei and Beek, Mathias van and Ragwitz, Mario}, title = {Utilizing Historical Operating Data to increase Accuracy for Optimal Seasonal Storage Integration and Planning}, series = {36th International Conference on Efficiency, Cost, Optimization, Simulation and Environmental Impact of Energy Systems (ECOS 2023), Las Palmas De Gran Canaria, Spain}, journal = {36th International Conference on Efficiency, Cost, Optimization, Simulation and Environmental Impact of Energy Systems (ECOS 2023), Las Palmas De Gran Canaria, Spain}, publisher = {ECOS}, doi = {10.52202/069564-0202}, pages = {2241 -- 2252}, abstract = {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.}, language = {en} } @misc{PopovskiFleiterRagwitz, author = {Popovski, Eftim and Fleiter, Tobias and Ragwitz, Mario}, title = {The role of solar district heat in the energy transition of the German heating sector}, series = {Energy}, volume = {310}, journal = {Energy}, publisher = {Elsevier}, abstract = {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.}, language = {en} } @misc{RagwitzBillerbeckBernathetal., author = {Ragwitz, Mario and Billerbeck, Anna and Bernath, Christiane and Manz, Pia and Deac, Gerda and Held, Anne and Winkler, Jenny and K{\"o}k, Ali}, title = {Integrating district heating potentials into European energy system modelling : an assessment of cost advantages of renewable and excess heat}, series = {Smart Energy}, volume = {15}, journal = {Smart Energy}, publisher = {Elsevier}, doi = {10.1016/j.segy.2024.100150}, pages = {1 -- 13}, abstract = {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.}, language = {en} } @misc{GeorgeHeldWinkleretal., author = {George, Jan Frederick and Held, Anne and Winkler, Jenny and Eichhammer, Wolfgang and Ragwitz, Mario}, title = {Unveiling the cost competitiveness of sector coupling technologies : policy impacts on levelised costs of heat pumps and battery electric vehicles in Germany}, series = {Smart Energy}, volume = {15}, journal = {Smart Energy}, publisher = {Elsevier BV}, issn = {2666-9552}, doi = {10.1016/j.segy.2024.100149}, pages = {1 -- 15}, abstract = {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.}, language = {en} } @misc{SporlederRathRagwitz, author = {Sporleder, Maximilian and Rath, Michael and Ragwitz, Mario}, title = {Solar thermal vs. PV with a heat pump: a comparison of different charging technologies for seasonal storage systems in district heating networks}, series = {Energy Conversion and Management: X}, volume = {22}, journal = {Energy Conversion and Management: X}, publisher = {Elsevier BV}, issn = {2590-1745}, doi = {10.1016/j.ecmx.2024.100564}, pages = {27}, abstract = {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.}, language = {en} } @misc{BillerbeckKieferWinkleretal., author = {Billerbeck, Anna and Kiefer, Christoph P. and Winkler, Jenny and Bernath, Christiane and Sensfuß, Frank and Kranzl, Lukas and M{\"u}ller, Andreas and Ragwitz, Mario}, title = {The race between hydrogen and heat pumps for space and water heating: A model-based scenario analysis}, series = {Energy Conversion and Management}, volume = {299}, journal = {Energy Conversion and Management}, publisher = {Elsevier BV}, issn = {0196-8904}, doi = {10.1016/j.enconman.2023.117850}, pages = {19}, abstract = {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.}, language = {en} } @techreport{KoltzerSchoenherrSporlederetal., author = {Koltzer, Nora and Schoenherr, Johannes and Sporleder, Maximilian and Niederau, Jan and Ragwitz, Mario}, title = {Repurposing idle wells in the North German Basin as deep borehole heat exchangers}, series = {Geothermal Energy}, volume = {12 (2024)}, journal = {Geothermal Energy}, doi = {10.1186/s40517-024-00315-4}, abstract = {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.}, language = {en} } @techreport{GeorgeMarxHeldetal., author = {George, Jan Frederick and Marx, Alexander and Held, Anne and Winkler, Jenny and Bekk, Anke and Ragwitz, Mario}, title = {Balancing the books: unveiling the direct impact of an integrated energy system model on industries, households and government revenues}, series = {Energy, Sustainability and Society}, volume = {14 (2024)}, journal = {Energy, Sustainability and Society}, publisher = {Springer}, doi = {10.1186/s13705-024-00450-7}, pages = {29}, abstract = {Background The transition towards a sustainable energy system is reshaping the demand for final energy, driven by the diffusion of new end-use technologies. This shift not only impacts consumers' energy expenses, but also holds implications for the public budget. Building on data from a German energy transition scenario, we analyse the direct impact of energy costs on industries, low-income households, and changes in government revenues from the taxes and levies on final energy carriers. Our analysis considers the impact of current policies and explores a scenario introducing additional excise tax rates to offset potential revenue losses. Results We found that substantial carbon price increases could generate revenues that offset the losses from excise taxes on fossil fuels while enabling the financing of renewable support from the public budget by the end of this decade. Nevertheless, a decline in government revenues from taxes and levies is anticipated after 2030 until the middle of the century due to the declining use of fossil fuels. Maintaining current excise tax revenues during the transition could be achieved by introducing additional excise taxes on fossil fuels and electricity. Lastly, our analysis indicated a continuous decline in household energy expenditures until 2050, whereas energy-intensive industries face adverse impacts due to decarbonisation. Conclusions This research provides valuable insights into the fiscal implications of the energy transition, shedding light on different industrial sectors and households while considering the evolving impact on the public budget. Policymakers may need to consider systemic reforms or alternative financing mechanisms outside the energy system to balance the books.}, language = {en} }