Search

The majority of freight in Germany is carried out by trucks, resulting in emitting approximately 9% of Germany's carbon dioxide equivalent emissions. In particular, long-distance truck journeys contribute significantly to these emissions. This paper aims to explore the conditions and impacts of introducing E-Trucks in Germany by utilizing a microscopic traffic simulation approach. Therefore, five different electrification levels of the long-distance truck traffic are evaluated. The demand-oriented charging network dimensioning aims for a realistic and implementable design and is based on an average charging power of 720 k W. Additionaly, it considers the necessary infrastructure requirements at service and rest areas next to the motorway. The results of this research provide valuable insights in terms of usage, requirements and demand. For an electrification level of 1%, 177 chargers at 173 charging sites must be implemented, while 1296 chargers and 457 charging sites must be built for an electrification level of 20%. The increase in the electrification level leads to more efficient occupancy of the charging facilities; i.e., an increase from 1% to 5% improves the average occupation time ratio per charger by approximately 130%. Of the total energy consumed, 65% is recharged en-route at public chargers. Between Monday and Thursday, each 1% electrification level increase requires 2.68 G W   h more energy for the public recharging network. [ABSTRACT FROM AUTHOR]

The Nibelungen bridge as a pilot project for digitally assisted structural maintenance The construction industry is one of the main consumers of natural resources and contributes significantly to CO2 emissions in Germany with an annual waste volume of 54 %. Therefore, the preservation of existing buildings can make a significant contribution to environmental protection and resource conservation. However, effective monitoring and maintenance concepts are needed to extend the service life of structures while maintaining their stability and functionality. This paper deals with a pilot project in which the Nibelungen Bridge Worms serves as a validation object to develop a new, digitally supported maintenance strategy. First, the bridge and its maintenance history will be presented. Subsequently, the pilot project is put into the context of the DFG priority programme SPP 2388 "Hundert plus". Afterwards, the specific key aspects including geometric modelling, structural health monitoring (SHM), digital twinning, level 4 recalculation and the assessment of detected structural damages are described. Finally, conclusions and outlooks are given. [ABSTRACT FROM AUTHOR]

The growing share of fluctuating renewable electricity production within the German energy system causes the increasing necessity for flexible consumers, producers, and storage technologies to balance supply and demand. District heating networks with combined heat and power units, Power-to-Heat applications, and thermal energy storage capacities can serve as one of these flexible options. In this context, a simulation model of the district heating network of the rural community Dollnstein, Germany, was built. With the residual load of different regional areas (Germany, Bavaria, Eichstätt, Dollnstein) it is investigated, how the heat generators can operate in an electricity market beneficial way. Two different control algorithms were evaluated: Due to a correlation between the residual loads and the CO2 emissions of the electricity mix, the CO2 savings achieved by this control algorithm are determined. Another way to operate electricity market beneficial is to consider the current CO2 emissions of each region. The main outcomes of this paper are, that there is a high potential for sector coupling by shifting the operation times of a CHP and a heat pump according to the residual load. The electricity demand of the heat pump can be met in terms of low CO2 emissions of the electricity mix, while the CHP can replace electricity with high CO2 emissions. These results can be improved, by considering not the residual load but the current CO2 emissions in the control algorithm. [ABSTRACT FROM AUTHOR]

Human-induced climate change is one of the most pressing challenges of our time. The Helmholtz Association is making essential research contributions to mitigate the causes and impacts of climate change and find ways to adapt. The "Net-Zero-2050" project, the Cluster I of the Helmholtz Climate Initiative, scientifically investigates and evaluates strategies and new ways to reduce, extract and permanently store carbon emissions. Two digital knowledge transfer products (DKTPs) were developed to present the complex research results comprehensively: (1) the "Net-Zero-2050 Web-Atlas" provides information on methods and technologies for CO 2 reduction and possible reduction paths; (2) the "Soil Carbon App" provides simulated soil carbon data to estimate climate protection potentials through different land management methods. Both formats intend to support users in making informed decisions and developing appropriate climate neutrality strategies. During the two DKTPs development, common main challenges were identified regarding concepts and stakeholder involvement. Along with that, specific approaches to solving the tasks could be distilled for each product. In the still-evolving arena of digital knowledge transfer, no standard methods can be applied. At the same time, communication of climate research results to decision-makers is becoming more and more relevant. This paper extracts the challenges and gives approaches to facilitate a transfer of the gained experience to future similar projects. [ABSTRACT FROM AUTHOR]

This paper aims to quantify the relation between real GDP, CO2 emissions, renewable and nonrenewable energy consumption, tourism development and labor force for France and Germany as these two countries are pioneer countries pushing Paris agreement within and outside the European Union. The time spans have been used for the period of 1995–2015 according to data availability. In the presence of cross-sectional dependency, several first and second-generation unit root tests confirm the unit root problem while Pedroni and Westernlund confirm the cointegration. Results reveal an inverted U-shape relation between CO2 emissions and real GDP in long run confirming the validity of environmental Kuznets curve for the group of France and Germany. Results declare that renewable energy significantly reduces carbon emissions while nonrenewable energy consumption adds to carbon emissions. Tourism sector was found helpful in carbon reduction that appeals to attract more tourists for the development of sustainable tourism industry by taking energy conservation and emissions reduction in relevant industries in the full consideration. • This paper explores the determinants of carbon emissions for France and Germany. • An inverted U-shape relation was found between carbon emissions and real GDP in long run. • Results reveal renewable energy helps in carbon emissions reduction. • Nonrenewable energy consumption was adding in CO2 emissions. • Tourism sector was found supportive in carbon reduction. [ABSTRACT FROM AUTHOR]

This study explores the relationships between carbon emissions and their main determinants such as energy consumption, real income and international trade, in 15 European countries, employing data for the period 1960–2015, and in Germany, for that of 1970–2015. The purpose of this paper is to examine the environmental Kuznets curve in subregimes in the presence of structural shifts. Two complementary unit root tests are employed to examine the stationarity of employed variables. The Ng and Perron Econometrica 69: 1519–1554 (2001) and the Zivot and Andrews J Bus Econ Stat, 10(3), 251–270 (1992) unit root tests, both allow for a structural break. To estimate the parameters of the regression model and to detect structural breaks in the model, the Kejriwal and Perron J Econ, 146(1), 59–73, (2008), J Bus Econ Stat, 28(4), 503–522, (2010a), J Time Ser Anal, 31, 305–328, (2010b)) structural break test is employed. When structural breaks are allowed in estimations, the empirical results provide strong evidence of fluctuating relationships between CO2 emissions and income expressed by the U-shape in every subregime, which contradicts early findings in the literature of inverse U-shape environmental Kuznets curve. [ABSTRACT FROM AUTHOR]

In the European Union, peatlands are largely drained for agriculture resulting in significant environmental damage and CO 2 emissions. Rewetting is seen as an effective tool to reduce CO 2 emissions, but drainage-based agricultural practices are locked-in. Instead of describing the scaling up of agriculture on wet peatlands, this paper examines the termination of drained peatlands use as an exnovation problem. Drawing on sustainability transitions research, we suggest exnovation as a conceptual perspective on the systemic changes towards sustainable agriculture. We propose a perspective on exnovation governance based on four dimensions: discourse, policy instruments, agency, and justice. We assess existing recommendations and government policy for peatland rewetting in Germany in terms of exnovation governance, and highlight strengths and omissions. The exnovation approach provides a new perspective for decision-makers, while peatland also offers a promising avenue for further research within this framework. • Rewetting of peatlands should be understood as the deliberate termination of the practice of drainage. • We spell out peatland rewetting as exnovation problem with four dimensions: discourse, policy instruments, agency, and justice. • Termination should be part of a governance strategy for a sustainability transition within the agricultural sector. • The exnovation perspective on rewetting offers a theoretically founded, systematic underpinning for existing policy suggestions. [ABSTRACT FROM AUTHOR]

The EU has established the world's first cross-border emission-trading systems (ETS) for greenhouse gas (GHG) emissions, currently covering aviation, emission-intensive sectors, and electricity (EITE). The EU Commission has offered to apply emissions trading in new sectors where emissions from maritime transport will be incorporated into the current EU ETS, while a separated emissions trading system will cover emissions from road transport and the building sector. This paper employs a multi-regional multi-sectoral computable general equilibrium (CGE) model with two simultaneous international emission permit markets. After examining the abatement costs for the EU regions, various policy scenarios are implemented to study the welfare effects of forming an ETS covering the sectors other than EITE (NEIT) and its linking with the EITE sectors under two different baselines and four emission reduction targets. The results provide several important insights: (i) Marginal abatement costs in Germany and the Eastern European Union region (EEU) are significantly lower than in the rest of the EU regions. (ii) The carbon price in the emission permit market covering NEIT is significantly higher than the carbon price in the emission permit market covering EITE. (iii) Germany and EEU appear as notable suppliers of emission permits in both markets. (iv) There is a significant aggregate welfare gain under the scenario in which the ETS covering NEIT co-exists parallel with the ETS covering EITE. (v) The aggregate welfare in the EU under the full integration of EITE and NEIT may fall below its value under the scenario with two parallel emission permit markets. [ABSTRACT FROM AUTHOR]

While current climate targets demand substantial reductions in greenhouse gas emissions, the potentials to further reduce carbon dioxide emissions in traditional primary steel-making are limited. One possible solution that is receiving increasing attention is the direct reduction (DR) technology, operated either with renewable hydrogen (H 2) from electrolysis or with conventional natural gas (NG). DR technology makes it possible to decouple steel and H 2 production by temporarily using overcapacities to produce and store intermediary products during periods of low renewable electricity prices, or by switching between H 2 and NG. This paper aims to explore the impact of this decoupling on overall costs and the corresponding dimensioning of production and storage capacities. An optimization model is developed to determine the least-cost operation based on perfect-foresight. This model can determine the minimum costs for optimal production and storage capacities under various assumptions considering fluctuating H 2 and NG prices and increasing H 2 shares. The model is applied to a case study for Germany and covers the current situation, the medium term until 2030, and the long term until 2050. Under the assumptions made, direct reduced iron (DRI) storage mainly serves as long-term storage for several weeks, similar to usual balancing storage capacities. Storing H 2 , on the contrary, is used for short-term fluctuations and could balance H 2 demand in the hourly range until 2050. From an economic perspective, DRI production using NG tends to be cheaper than using H 2 in the short term, and potential savings from the flexible operation with storages are initially small. However, in the long term until 2050, NG and H 2 could achieve similar total costs if buffers are used. Otherwise, temporarily occurring electricity price spikes imply substantial increases in total costs if high shares of H 2 need to be achieved. [Display omitted] • Investigation of the use of renewable hydrogen in primary steel-making. • Analyses of flexible operation with natural gas and hydrogen in direct reduction. • Modeling optimal dimensions and minimum costs under increasing renewable shares. • Case study on optimal hydrogen and direct-reduced iron storages. [ABSTRACT FROM AUTHOR]

Global crude steel production is expected to continue to increase in the coming decades to meet the demands of the growing world population. Currently, the dominant steelmaking technology worldwide is the conventional highly CO2 -intensive blast furnace–basic oxygen furnace production route (also known as the Linz–Donawitz process), which uses iron ore as raw material and coke as a reducing agent. As a result, large quantities of special gases that are rich in carbon monoxide (CO) are by-products of the various stages of the steelmaking process. Given the challenges associated with satellite-based estimates of carbon dioxide (CO2) emissions at the scale of emitting installations due to significant background levels, co-emitted CO may serve as a valuable indicator of the carbon footprint of steel plants. We show that regional CO release from steel production sites can be monitored from space using 5 years of measurements (2018–2022) from the TROPOspheric Monitoring Instrument (TROPOMI) on board the Sentinel-5 Precursor satellite, benefiting from its relatively high spatial resolution and daily global coverage. We analyse all German steel plants with blast furnaces and basic oxygen furnaces and obtain associated CO emissions in the range of 50–400 kt yr -1 per site. A comparison with the respective CO2 emissions on the level of emitting installations available from emissions trading data of the European Union Emissions Trading System yields a linear relationship with a sector-specific CO/CO2 emission ratio for the analysed steelworks of 3.24 % [2.73–3.89; 1 σ ], suggesting the feasibility of using CO as a proxy for CO2 emissions from comparable steel production sites. An evaluation at other steel production sites indicates that the derived CO/CO2 emission ratio is also representative of other highly optimised state-of-the-art Linz–Donawitz steelworks outside Germany and that the emission ratio is potentially valuable for estimating sector-specific CO2 emissions from remotely sensed CO emissions, provided that the underlying CO emission estimate is not affected by other sources. [ABSTRACT FROM AUTHOR]

To reach their net‐zero targets, countries will have to compensate hard‐to‐abate CO2 emissions through carbon dioxide removal (CDR). Yet, current assessments rarely include socio‐cultural or institutional aspects or fail to contextualize CDR options for implementation. Here we present a context‐specific feasibility assessment of CDR options for the example of Germany. We assess 14 CDR options, including three chemical carbon capture options, six options for bioenergy combined with carbon capture and storage (BECCS), and five options that aim to increase ecosystem carbon uptake. The assessment addresses technological, economic, environmental, institutional, social‐cultural and systemic considerations using a traffic‐light system to evaluate implementation opportunities and hurdles. We find that in Germany CDR options like cover crops or seagrass restoration currently face comparably low implementation hurdles in terms of technological, economic, or environmental feasibility and low institutional or social opposition but show comparably small CO2 removal potentials. In contrast, some BECCS options that show high CDR potentials face significant techno‐economic, societal and institutional hurdles when it comes to the geological storage of CO2. While a combination of CDR options is likely required to meet the net‐zero target in Germany, the current climate protection law includes a limited set of options. Our analysis aims to provide comprehensive information on CDR hurdles and possibilities for Germany for use in further research on CDR options, climate, and energy scenario development, as well as an effective decision support basis for various actors. Plain Language Summary: Countries aiming to achieve net‐zero emissions will have to remove the remaining carbon dioxide from the atmosphere through carbon dioxide removal (CDR). However, current assessments of CDR options rarely consider socio‐cultural or institutional aspects or set the CDR options in the specific context of their implementation. In this study, researchers conducted the first context‐specific feasibility assessment of CDR options in Germany, considering six dimensions, including technological, economic, environmental, institutional, and social‐cultural aspects. The study assessed 14 CDR options, including chemical carbon capture options, bioenergy combined with carbon capture and storage, and options to increase ecosystem carbon uptake. The study found that CDR options like cover crops or seagrass restoration face low implementation hurdles but have small CO2 removal potentials, while options like woody‐biomass combustion or mixed‐feedstock biogas production have high CDR potentials but face large economic and institutional hurdles. The analysis aims to provide comprehensive information on CDR options for use in further research and as an effective decision support basis for a range of actors. Key Points: More context‐specific assessments of carbon dioxide removal (CDR) options are needed to guide national net‐zero decision makingEcosystem‐based CDR options with comparably low implementation hurdles in Germany show relatively small CO2 removal potentialsHigh CDR potential options in Germany face high institutional, technological and societal hurdles linked in many ways to geological storage [ABSTRACT FROM AUTHOR]

This study assesses alternative energy technologies (i.e., PV and battery systems, electric heat pumps, hybrid gas heating with solar thermal energy) in terms of profitability and CO 2 emissions, for the case of two simulated typical households living in detached houses in Germany. Under the status-quo regulatory framework, the energy transition in the heating sector is fostered through grants for replacing old heating systems, whereas PV generation is fostered by feed-in tariffs and indirect subsidies for self-consumption. This study considers an alternative regulatory scenario with a more market-oriented approach, finding that a CO 2 -oriented reform of energy surcharges and taxes, as well as a reform of network charges, can support a more cost-efficient energy transition in the residential sector. The paper concludes with a discussion of the consistency, cost efficiency and effectiveness of past and current policies underpinning the energy transition in the residential sector. • Assessment of home energy systems across 2 households and 2 regulatory scenarios. • Consideration of PV, batteries, heat pumps and hybrid gas-solar heating systems. • Comparison of subsidies and flat energy tariffs vs. cost-reflective, dynamic tariffs. • Market-oriented approach incentivizes far more cost-efficient CO 2 emission reduction. • The German residential energy sector needs a consistent regulatory framework. [ABSTRACT FROM AUTHOR]

The frequent dry-wet cycles in the Loess Plateau can lead to the deterioration of fiber-reinforced loess (FR loess), which in turn can cause collapse when exposed to rainfall erosion or immersion. In recent years, geopolymers have received considerable attention due to their advantages, such as solid waste disposal and low carbon dioxide emissions. In this paper, the effects of geopolymer, consisting of steel slag (SS), ground granulated blast furnace slag (GGBS), desulfurization gypsum (DG), and sodium silicate, on the durability and water stability of FR loess were studied by conducting dry-wet cycle tests, immersion tests, and unconfined compression tests. The results show that the unconfined compressive strength (UCS) of fiber-reinforced and geopolymer-stabilized loess (FRG loess) decreases exponentially with the increase of dry-wet cycles while increasing approximately linearly with geopolymer dosage. The water stability coefficient of FRG loess shows a logarithmic increase with dry-wet cycles and increases linearly with geopolymer dosage, and the higher the dosage, the greater the water stability. The stabilization and dry-wet deterioration mechanisms of FRG loess were investigated by XRD and SEM-EDS tests. It reveals that the main mineral phases of FRG loess are calcium silicate hydrate, calcium aluminate hydrate, calcium aluminate silicate hydrate gel, and ettringite crystal. The microstructure of FRG loess is quite dense, but after the dry-wet cycles, it appears some cracking and loosening. The pores and microcracks of the low-dosage samples develop distinctly under dry-wet cycles, whereas the microstructure of high-dosage samples shows significant overall stability. The study on the durability and water stability of FRG loess under dry-wet cycles suggests that the optimal geopolymer dosage should be 15%. • The dry-wet durability and water stability of fiber-reinforced and geopolymer-stabilized loess were investigated. • The influence of the dry-wet cycles and the geopolymer dosage on the water stability coefficient was discussed. • The XRD and SEM-EDS tests were used to reveal the mechanism of stabilization and deterioration. [ABSTRACT FROM AUTHOR]

Future transport systems will rely on new electrified drives utilizing batteries and hydrogen-powered fuel cells or combustion engines with sustainable fuels. These systems must complement each other and should not be viewed as competing. Properties such as efficiency, range, as well as transport and storage properties will determine their use cases. This article looks at the usability of liquid electro-fuels in freight transport and analyzes the production capacities that will be necessary through 2050 in Germany. Different scenarios with varying market shares of electro-fuels are considered. A scenario with a focus on fuel cells foresees a quantity of 220 PJ of electro-fuels, i.e., 5.1 million tons, which reduces 80% of carbon dioxide emissions in LDV and HDV transport. A further scenario achieves carbon-neutrality and leads to a demand for nearly 17 million tons of e-fuel, corresponding to 640 PJ. Considering a final production rate of 5.1 million tons of electro-fuels per year leads to maximum investment costs of around EUR 350 million/year in 2036 during the ramp-up phase. The total investment costs for synthesis plants amount to EUR 4.02 billion. A carbon-neutrality scenario requires more than a factor 3 for investment for the production facilities of electro-fuels alone. [ABSTRACT FROM AUTHOR]

Greenhouse gas (GHG) emissions from rivers are globally relevant, but quantification of these emissions comes with considerable uncertainty. Quantification of ecosystem-scale emissions is challenged by both spatial and short-term temporal variability. We measured spatio-temporal variability of CO 2 and CH 4 fluxes from a 1 km long reach of the lowland river Elbe in Germany over 3 d to establish which factor is more relevant to be taken into consideration: small-scale spatial variability or short-term temporal variability of CO 2 and CH 4 fluxes. GHG emissions from the river reach studied were dominated by CO 2 , and 90 % of total emissions were from the water surface, while 10 % of emissions were from dry fallen sediment at the side of the river. Aquatic CO 2 fluxes were similar at different habitats, while aquatic CH 4 fluxes were higher at the side of the river. Artificial structures to improve navigability (groynes) created still water areas with elevated CH 4 fluxes and lower CO 2 fluxes. CO 2 fluxes exhibited a clear diurnal pattern, but the exact shape and timing of this pattern differed between habitats. By contrast, CH 4 fluxes did not change diurnally. Our data confirm our hypothesis that spatial variability is especially important for CH 4 , while diurnal variability is more relevant for CO 2 emissions from our study reach of the Elbe in summer. Continuous measurements or at least sampling at different times of the day is most likely necessary for reliable quantification of river GHG emissions. [ABSTRACT FROM AUTHOR]

The present millennium records the most devastating effects of global warming than what was evident in the pre-industrial era. The pervasive effects of global warming have raised concerns about the sustainability of the present and future generations. Hence, researchers are working assiduously towards proffering the most effective method of halting the surging emissions from global, regional, and national angles. This study contributes to the extant literature by providing the first empirical verification of how renewable energy, technological innovations, trade openness, and transport services impact carbon emissions in Germany. The empirical evidence is anchored on annual time series data from 1990 to 2020 estimated using the novel nonlinear ARDL to explore the positive and negative shocks associated with the short and long-run nexus. The wavelet coherence estimator is equally for ascertaining the multiple time scales in the time series and extends the knowledge frontier to the literature. The following findings are eminent from the overall analyses. First, long-run cointegration is supported among the variables of interest Second, only the adverse effects of renewable energy and technology are substantial enough to mitigate carbon emissions. The trade-induced emissions are established with the positive impacts of trade openness on carbon emissions. Transport services contribute significantly to carbon emissions in the long-run and short-run periods. However, mitigating effects of small magnitude are apparent in the long-run due to the perceived transition to green transportation. Policy implications supporting the transition to 100% renewable energy and green transportation are significant steps towards achieving Germany's carbon neutrality target. [ABSTRACT FROM AUTHOR]

Considering the rapid development of the global digital industry and the need for sustainable development and climate change, this paper explores the global ICT-embodied CO 2 emissions changes and intensities from 2000 to 2014, and the driving factors behind ICT-embodied CO 2 emissions changes in 15 countries by using the multi-regional input–output (MRIO) method and structural decomposition analysis (SDA) method. We also use Monte Carlo simulations to forecast the ICT-embodied CO 2 emissions from 2020 to 2050. The results indicate that: (1) After 2009, global ICT's embodied CO 2 emissions first decline and then increase, and the sector that manufactures computer, electronic, and optical products account for 82.83% of the global ICT's embodied CO 2 emissions in 2014; (2) judging from the emission-reduction trends of various countries, CO 2 emissions intensity factors are the main drivers restricting the growth of embodied CO 2 emissions in the ICT sector, while final demand composition factors play a significant role in promoting the increase of ICT's embodied CO 2 emissions; (3) Australia, Germany, and Indonesia contribute to an increase in ICT's embodied CO 2 emissions due to sectoral heterogeneity, while Canada, China, Germany, and South Korea have contributed to an increase in ICT's embodied CO 2 emissions in terms of regional heterogeneity; (4) the drivers have also changed significantly with the impact of the financial crisis; and (5) with the current pattern of development, it is difficult to reach the peak of ICT-embodied CO 2 emissions in most countries before 2050. This paper also provides feasible implementation plans for carbon mitigation in the global ICT industry. • We analyze the global ICT-embodied CO 2 emissions changes and their driving factors. • The structural decomposition analysis (SDA) method is utilized. • Final demand composition factors play a key role in ICT's embodied CO 2 emissions. • ICT-embodied CO 2 emissions of Australia, Germany, and Indonesia increase due to sectoral heterogeneity. • It is difficult to reach the peak of ICT-embodied CO 2 emissions in most countries before 2050. [ABSTRACT FROM AUTHOR]

Considering climate change, it is essential to reduce CO 2 emissions. The provision of charging infrastructure in public spaces for electromobility – along with the substitution of conventional power generation by renewable energies – can contribute to the energy transition in the transport sector. Scenarios for the spatial distribution of this charging infrastructure can help to exemplify the need for charging points and their impact, for example on power grids. We model two kinds of demand for public charging infrastructure. First, we model the demand for public charging points to compensate for the lack of home charging points, which is derived from a previously developed and published model addressing electric-vehicle ownership (with and without home charging options) in households. Second, and in the focus of the work presented here, is the demand for public charging infrastructure at points of interest (POIs). Their locations are derived from OpenStreetMap (OSM) data and weighted based on an evaluation of movement profiles from the Mobilität in Deutschland survey (MiD, German for "Mobility in Germany"). We combine those two demands with the available parking spaces and generate distributions for possible future charging points. We use a raster-based approach in which all vector data are rasterized and computations are performed on a municipality's full grid. The presented application area is Wiesbaden, and the methodology is generally applicable to municipalities in Germany. The model is compared with three other models or model variants in a correlation comparison in order to determine the influence of certain model assumptions and input data. The identification of potential charging points in public spaces plays an important role in modeling the future energy system – especially the power grid – as the rapid adoption of electric vehicles will shift locations of electrical demand. With our investigation, we would like to present a new method to simulate future public charging point locations and show the influences of different modeling methods. [ABSTRACT FROM AUTHOR]

This paper examines individual preferences for a reduction of life-cycle CO 2 emissions in vehicle purchase decisions. The empirical analysis is based on data from a stated choice experiment among citizens in Germany that refers to decisions between three types of electric vehicles and one conventional vehicle that are characterized by several attributes. With respect to CO 2 emissions, we specifically examine emissions in vehicle production besides the commonly considered emissions in vehicle use. Our econometric analysis reveals a strong stated preference for the reduction of both components of life-cycle CO 2 emissions. Furthermore, we find that conventional vehicles are significantly preferred over electric vehicles. Surprisingly, environmental attitudes, i.e. environmental awareness and ecological policy identification, have no significant effects on the reduction of CO 2 emissions. Instead, citizens with a strong environmental identity rather tend to avoid the purchase of conventional vehicles. We discuss several practical policy implications. [ABSTRACT FROM AUTHOR]

The Earth's population of seven billion consume varying amounts of planetary resources with varying impacts on the environment. We combine the analytical tools offered by the socio-ecological metabolism and class theory and contribute to a novel social stratification theory to identify the differences in individual resource and energy use. This approach is applied to German society, we use per capita greenhouse gas emissions (GHG) as a proxy for resource and energy use and investigate socio-metabolic characteristics of individuals from an economic, social and cultural perspective. The results show large disparities and inequalities in emission patterns in the German society. For example, the GHG in the lowest and highest emission groups can differ by a magnitude of ten. Income, education, age, gender and regional differences (Eastern vs. Western Germany) result in distinct emission profiles. We question the focus on individual behavioral changes and consumption choices to reduce carbon emissions instead of structural changes through political decisions. We argue that emission differences are directly linked to the effects of inequalities and class differences in capitalist societies. Our research results show that natural resource and energy consumption are important for explaining social differentiation in modern societies. [ABSTRACT FROM AUTHOR]

• Carbonation is a promising technology to sequester CO 2 emissions. • The locational aspects and transportation can influence the carbonation value chains significantly. • Regionalizing the analysis is of importance in order to obtain accurate results. • The economic feasibility will play a major role in determining the extent of utilizing the potential capacities. • Tracking the changes in the construction industry should be considered as they can significantly influence the supply chain. Carbon capture and utilization (CCU) is an essential method to sequester unavoidable CO 2 emissions in regions with insufficient geological storage capacities. Nonetheless, there are several uncertainties and knowledge gaps in terms of the future value chains of some CCU technologies (e.g. carbonation). This paper analyzes the potentials of coupling CCU with the supply chains of the construction industry by means of carbonating the concrete products and waste concrete in the German federal state of North Rhine–Westphalia. Based on extensive data and statistical analyses, the locations and outputs of the concrete and recycling plants have been determined in order to quantify their CO 2 sequestration capacities. Location-allocation models have been applied to allocate the carbon sources to the potential carbon sinks and calculate the minimum transportation costs. The analysis shows that the total annual sequestration capacity is up to 1 Mt CO 2 with an average transportation distance of 37.4 km (8.3 EUR/ton). Nonetheless, some emission sources have a clear comparative advantage in terms of their proximity to the carbon sinks as the distance ranges between 0.7 km and 99.7 km. Also, some carbon sinks have a comparative advantage in terms of capacities and technology readiness levels. Therefore, the paper also presents models for the different products in order to display the potentials of each category separately and offer more flexibility to the stakeholders. [ABSTRACT FROM AUTHOR]

ABSTRACT Using data from the German Socio-Economic Panel (GSOEP), we show that nearly 50% of all carbon emissions caused by private transportation and building operations in Germany can be explained by structural determinants that go hand in hand with infrastructural peculiarities in rural and urban residential areas. Taking the theoretical background of building physics, allometry and increasing returns to scale as a vantage point, this paper analyses the effects of physical concentration - e.g. apartment buildings versus bungalows - and social compactness - e.g. multigenerational versus single households. In contrast to related studies, this perspective reveals that social and physical concentration tend to counteract each other and thus clarifies the intricate interactions between household structure, different infrastructural environments and carbon emissions. A supplementary finding is that the spatial distribution of fuel types plays a large role in explaining lower carbon emissions in urban settlements. This leads us to the conclusion that environmental policy should foster physical concentration in rural and social concentration in urban infrastructural environments. Copyright © 2012 John Wiley & Sons, Ltd and ERP Environment. [ABSTRACT FROM AUTHOR]

This study estimates total, inland, water and air transport net forward, backward and internal carbon linkages of EU's top seven emitters from 1995 to 2011. Moreover, it also reports direct emissions and intensities. Direct emissions of the seven for all four sectors mostly increased with varying proportions, while direct intensities followed a downward trend. Total, inland, water and air net backward emissions were reasonably stable excluding Germany who's total and inland net backward emissions sharply declined during 2000 while water and air emissions increased sharply. Although some nations witnessed a decrease, overall total, inland and air transport net forward emissions increased. While water transport net forward emissions had huge fluxes in the middle, stabilised towards the end. Total, inland, and air transport internal emissions for most of the nations increased over time. However, water transport internal emissions except for the UK were reasonably stable. 'Electricity, Gas and Water Supply' was the top source of German; Polish; Italian; British and Dutch net backward emissions. France and Spain's highest carbon imports were from 'Coke, Refined Petroleum and Nuclear Fuel.' Highest destinations of net forward emissions keep changing over time. The paper also discusses policy implications. Image 1 • Extended modified hypothetical extraction model to time series and cross-regional analysis. • Estimated total, inland, water and air transport carbon linkages of EU's top seven emitters from 1995 to 2011. • Also reported direct emissions and intensities. • On average forward and internal linkages increased while backward linkages marginally decreased. [ABSTRACT FROM AUTHOR]

For an extensive decarbonization of district multi-energy systems, efforts are needed that go beyond today's cogeneration of heat and power in district multi-energy systems. The multitude of existing technical possibilities are confronted with a large variety of existing multi-energy system configurations. The variety impedes the development of universal decarbonization pathways. In order to tackle the decarbonization challenge in existing and distinct districts, this paper calculates a wide range of urban district configurations in an extensive co-simulation based on domain specific submodels. A district multi-energy system comprising a district heating network, a power grid, and cogeneration is simulated for two locations in Germany with locally captured weather data, and for a whole year with variable parameters to configure a power-to-heat operation, building insolation/refurbishment, rooftop photovoltaic orientation, future energy demand scenarios, and district sizes with a temporal resolution of 60 s, in total 3840 variants. The interdependencies and synergies between the electrical low-voltage distribution grid and the district heating network are analysed in terms of efficiency and compliance with network restrictions. Thus, important sector-specific simulations of the heat and the electricity sector are combined in a holistic district multi-energy system co-simulation. The clearly most important impact on emission reduction and fuel consumption is a low heat demand, which can be achieved through thermal refurbishment of buildings. Up to 46 % reduction in CO 2 emissions are possible using the surplus electricity from photovoltaics for power-to-heat in combination with central heat storage in the district's combined heat and power plant. Domestic hot water heated by district heating network in combination with power-to-heat conversion distributed in the district reduces the load on the distribution power grid. Even though the investigated measures already improve the sustainability significantly, providing the energy needed for the production of synthetic fuels remains the crucial challenge on the further path towards net-zero. • Cross-sectoral simulation of a district multi-energy system in 3840 configurations. • Impact quantification for different structural conditions and construction measures. • Calculation of the remaining effort to reach net-zero using synthetic fuels. [ABSTRACT FROM AUTHOR]

Although the circular economy primarily focuses on closing supply chains, residual waste management, and product lifetime extensions, reducing resource use remains critical. This paper examines the system-wide impacts of reducing resource use using a multisectoral computable general equilibrium model. Although not strictly circular, the focus is on a costless 'technology shock' that reduces the consumption of intermediate goods in the construction sector and its system-wide effects. The results suggest that there is potential for reductions in CO 2 emissions, but this is accompanied with a fall in GDP and employment, with unskilled workers experiencing larger negative employment effects. However, the scale of these GDP and employment effects is small, despite relatively large reductions in resource use. This indicates that technology-induced reductions in resource use have the potential to support the transition towards an economy that uses fewer resources without causing significant disruptions at the macroeconomic level. • 'More for less' is of importance in the transition towards a more circular economy. • Assess implications of an improvement in the resource-use intensity of construction. • Employ a dynamic, multi-sectoral computable general equilibrium model for Germany. • Identify a slight trade-off between the resource-use improvement and economic effects. [ABSTRACT FROM AUTHOR]

Understanding how countries contribute to the generation of externalities globally is important for designing sustainable policies aimed at reducing negative externalities such as carbon emissions. Commonly used approaches focus on either producers or consumers, thereby neglecting the role of intermediates. We here introduce the concept of throughflow to comprehensively quantify upstream externalities generated by the supply chains originating from, passing through or ending in a given country. We define the Throughflow Based Accounting (TBA) framework as the decomposition of the throughflow into local, imported, exported and traversing externalities. We illustrate the strength of the TBA by identifying the CO2 emissions caused by supply chains involving the German economy. We show that Germany could use its position in global value chains to help reduce two times more CO2 emissions than measured with usual production- or consumption-based accounting frameworks. [ABSTRACT FROM AUTHOR]

Germany's climate goals require over 75% of its housing stock to be retrofitted for energy efficiency. An important question for Germany and other countries is, what minimum energy efficiency standard should be mandated for housing retrofits so as to reduce CO2 emissions economically efficiently? It has long been known that the marginal costs of energy efficiency increase as standards are pushed higher, and therefore the marginal costs of CO2 abatement increase, but at the same time energy consumption reduces, thereby reducing CO2 emissions. This paper investigates where the social optimum lies between these two effects. In addition to a large database of house sale advertisements containing price and energy efficiency data, it uses two semi-official data sources of modelled and actual energy efficiency upgrades in Germany. It finds that retrofitting to a modestly high standard of about 70 kWh/m2/y entails marginal costs of CO2 abatement comparable to current CO2 prices. However, each step to a higher standard increases these by up to an order of magnitude, with absurdly high marginal costs of CO2 abatement for the highest standards. German policymakers are currently pushing for higher minimum standards, but money could better be spent retrofitting more houses to less stringent standards. • Policymakers seek to drive energy efficiency in buildings to ever higher levels. • But costs of CO2 abatement rise extremely sharply as standards tighten. • Use cost data on retrofits of German buildings to various efficiency standards. • Retrofits to current standards are at the limit of CO2 abatement efficiency. • Driving standards higher increases CO2 abatement cost by an order of magnitude. [ABSTRACT FROM AUTHOR]

Subsidizing homeownership decentralizes cities, as Muth (1967) suggested over half a century ago. This article focuses on the related question of whether repealing a homeownership subsidy recentralizes cities. This question is relevant today, given the ubiquity of homeownership subsidies. We provide a first quasi-experimental test of a subsidy repeal's spatial effects by examining Germany's 2005 homeownership subsidy reform. We find that repealing the subsidy contributed to recentralizing Germany's cities. Since recentralization helps abate carbon dioxide emissions, repealing a homeownership subsidy also helps mitigate climate change. [ABSTRACT FROM AUTHOR]

The electrification of the heating and transportation sectors is a major building block in Germany's effort to reduce carbon dioxide emissions. The additional loads and flexibilities resulting from the anticipated large-scale integration of the heating and transportation sectors necessitate an adequate representation in electricity market modeling. First, the paper presents a comprehensive modeling approach of the heating sector in a pan-European electricity market simulation considering both small-scale building heat pumps and large-scale conversion units with thermal energy storages in district heating networks. The operation of small-scale building heat pumps is emulated using an electro-thermal 1R1C building model integrated into the economic dispatch formulation while the operation of units in district heating networks is restricted by additional constraints resulting from the combined heat and power output, local heat load coverage and possible heat power transfer between heating networks. The transportation sector is mapped using previously published models by the authors including both controlled and fast charging processes. Subsequently, the load shift potentials resulting from the market-integration of the heating and transportation sectors and their impact on the pan-European electricity market with focus on Germany based on the three target years 2030, 2040 and 2045 are examined. Furthermore, by applying a Monte Carlo simulation to map possible future primary energy source prices a major uncertainty dimension is addressed. Considering the current German electricity market design, the integration of the two sectors lead to a moderate increase in future annual electricity demands and a substantial increase in market-based peak load. The resulting annual peak load from power-to-heat devices account to 22 GW (2030), 53 GW (2040) and 102 GW (2045) and from electric vehicles to 12 GW (2030), 36 GW (2040) and 96 GW (2045) for the target years. Further results demonstrate the larger load-shift potentials of electric vehicles compared to building heat pumps by comparing the weighted annual average market price of the flexible loads. The primary fuel price uncertainty is examined based on the 0.25, 0.50 and 0.75 quantiles for the target years which result in annual average electricity market price spreads of over 2.16 (2030), 2.97 (2040) and 3.44 (2045) between the 0.25 and 0.75 quantile scenarios. • Electricity market modeling considering the heating and transportation sectors. • Thermal building model to emulate operation of small-scale heat pumps. • Local heat load coverage and heat power transfer between heating networks. • Pan-European electricity market simulation based on the years 2030, 2040 and 2045. • Monte Carlo simulation to map future primary energy source prices. [ABSTRACT FROM AUTHOR]

[Display omitted] • Simulation of residential building energy supply with heat pump or hydrogen systems. • 2050: Hydrogen economically-viable if H 2 -/Elec.-price is less than 34–61 % per kWh. • For conservative price predictions: Electric heat pumps are most economical solution. • Energy carrier switch for single-family houses: H 2 -/Elec.-price below 44 % per kWh. • Energy carrier switch for multi-family houses: H 2 -/Elec.-price below 58 % per kWh. • Fuel cells are emerging as an economically-viable option for multi-family houses. Fossil-fueled heating in the building sector is responsible for 16 % of Germany's total CO 2 emissions. Options for the climate-neutral heating of buildings include renewable electricity or renewable hydrogen. In this paper, we conduct a bottom-up study to investigate the role of hydrogen in the climate-neutral energy supply of ten selected residential buildings in comparison to electricity-based systems. Based on a demand simulation and linear optimization of the supply system, sensitivity analyses identify the threshold values of the hydrogen price for the use of hydrogen technologies (hydrogen boilers or fuel cells) in building energy systems and make the quantities of hydrogen consumed visible. The results specify the first installations of hydrogen-operated fuel cells in multi-family houses if the hydrogen price reaches 0.17 €/kWh H2 in 2050 at an electricity price of 0.31 €/kWh el. Generally, for different building types and electricity supply prices, it indicates that the use of hydrogen becomes economically-viable if the price of hydrogen supply is in the range of 34–61 % of the price of the electricity supply per kWh and below. For the case of green hydrogen obtained using renewable electricity, it is highly questionable whether hydrogen supply will be that much cheaper than direct electricity supply, making its economical use in buildings uncertain. [ABSTRACT FROM AUTHOR]

The present study investigates the driving factors leading energy and carbon intensity of the economies of the USA and Germany, being two economies with different structures and dependencies on energy while they are among the world's economic and geopolitical leading players. Both decoupling and decomposition analysis (overall and sectoral) are applied to identify and rank factors defining carbon and energy intensity during the period from 2000 to 2017, with the so-called financial crisis being within this period. The decoupling analysis denotes that these advanced economies have reached a weak decoupling status, while decomposition analysis confirms the leading role of energy intensity in CO2 emissions, followed by the income (positive contribution) and the energy mix emerge as important factors with population (positive contribution) trend to be an additional factor only in the USA. [ABSTRACT FROM AUTHOR]

• E-scooters' car-trip substitution potential for e-scooters estimated on basis of based on German mobility data. • 13 % of daily car trips or 2 % of vehicle-kilometers traveled suitable for replacement. • Calculation of daily potential greenhouse gas reduction through by switching to e-scooters. • Maximum savings of 1.2% of transportation GHG achievable if replacing gasoline cars. • Savings highly dependent on use case; potentially negative for BEV-replacement potentially negative. This paper explores which trips currently made in Germany by personal motorized transportation could be replaced by e-scooters and what effect this would have on greenhouse gas emissions. This potential for substitution is estimated on the basis of data from the national household travel survey in Germany. Our analysis shows that 13% of the daily car trips, corresponding to 2% of the car kilometers in Germany, are suitable for replacement. Based on these results, we show that saving potentials of greenhouse gas emissions are heavily dependent on the general conditions of the specific use case (e.g. e-scooter lifetime) and the type of vehicle replaced. At best, a saving potential of about 5.8 kt of CO 2eq per day could be achieved when trips with conventional cars are replaced by e-scooter driving. However, if battery electric cars are replaced, an increase in emissions may even occur under certain conditions. [ABSTRACT FROM AUTHOR]

Establishing a circular economy for Xella's building materials – among them Autoclaved Aerated Concrete (AAC) – is and will be one of Xella's key ESG projects for the coming years. In Germany, Xella has made it its goal to duplicate the powder‐input in the main AAC‐products from annually 60,000 t to 120,000 t by 2030. AAC‐powder used today emerges from the processing of AAC production leftovers, cutting residues and leftovers returned from job sites. In order to achieve the 2030 goal, Xella Germany will (1) generate new sinks, and (2) leverage new sources for AAC‐powder. Current production recipes are designed to take up emerging powder‐quantities, but nothing beyond. The present study describes the inspection and evaluation of current powder input shares per product type and options for their full exploitation by recipe amendments. In 2021, prototypes for Ytong PP2‐0,35 and PP4‐0,50 containing 20 m.‐% powder, and Ytong PP4‐0,55 containing 30 m.‐% powder were developed by the Xella Technologie‐ und Forschungsgesellschaft mbH. In order to prospectively supply sufficient quantities of AAC‐powder, Xella Germany aims at leveraging waste‐AAC from building demolition, so called "post‐demolition AAC" or "pd‐AAC". We combined the "zero burden" and the "avoided burden methodology" to expand the life cycle assessment for the investigated circularity scenarios over the edge of waste generation. Our assessment revealed substitution credits of 0.55 kg CO2e/kg pd‐AAC for Ytong PP2‐0,35, and 0.43 respectively 0.33 kg CO2e/kg pd‐AAC for Ytong PP4‐050 and PP4‐0,55. The present study illustrates that our ambition to duplicate Xella Germany's powder consumption is achievable, when the new formulations are fully and consequently implemented. The recipe amendments have the potential to reduce expenditures for sand, quicklime, cement and gypsum/anhydrite, thereby reducing Xella Germany's annual (Scope 3) AAC carbon emissions up to 36 kt CO2e. [ABSTRACT FROM AUTHOR]

Nationally determined contributions were at the core of the Paris Agreement for the global response to climate change. However, with the geographical separation of production and consumption caused by international trade, traditional trade statistics can no longer accurately reflect the flows of economic value and carbon emissions between countries, which will affect the participation and implementation of global climate policies. Based on a multi-regional input–output model, we measured the embodied carbon flows of bilateral trade between developed countries represented by Germany and the US, discussed the decoupling relationship between embodied carbon and export-led growth, and finally used structural decomposition analysis (SDA) to show how the driving factors affect embodied carbon flow in German-US trade. We found that from 2000 to 2014, embodied carbon in German-US trade showed an overall downward trend. While Germany maintained a trade surplus with the US, it also maintained an embodied carbon surplus. In addition, embodied carbon and value added in Germany's exports to the US were mostly strongly decoupled, while in US exports to Germany were mostly weakly decoupled, and the two-way decoupling had been weakened in the later stage. The results of SDA showed that changes in carbon intensity clearly inhibited bilateral carbon flows, while trade scale effects promoted it. This study provided an opportunity to use trade to achieve carbon reduction and increased the possibility of providing a convenient and feasible market mechanism for emission reduction through international partnerships. [ABSTRACT FROM AUTHOR]

Based on a discrete choice experiment with 306 individuals from Germany, we examine the impact of the emissions-per-Euro-spent indicator (g/€ indicator) on people's travel behavior. This indicator, which was motivated by Hagedorn and Sieg (2019), makes cheap, but emission-intensive travel alternatives appear particularly harmful for the environment. We find that the g/€ indicator induces people to be more likely to choose the travel alternative with the lower indicator value. This effect persists even if participants are informed about general carbon dioxide (CO2) emissions. We also find that the steering effect of the g/€ indicator is stronger than for other emission indicators, especially for the costs of offsetting emissions. Our results thereby indicate that the g/€ indicator could be used as an effective steering instrument for people to rethink traveling with cheap, but emission-intensive means of transport, especially with ultra-low cost carriers. [ABSTRACT FROM AUTHOR]

Using a large sample of enterprises from a survey that was simultaneously conducted in Germany, Austria and Switzerland, we study the self-reported impacts of the adoption of "green" energy saving and related technologies (GETs). Our specific interest is in how different policy instruments associate with energy efficiency, the reduction of CO 2 emissions, and competitiveness at the firm level. A first set of equations tracks how policy relates to the adoption of green energy technologies in distinct areas such as production, transport, buildings, ICT or renewables. In a second set of equations, we test the perceived impacts of adoption by the managers of the firms. The results confirm a differentiated pattern of varied transmission mechanisms through which policy can affect energy efficiency and CO 2 emissions, while on average having a neutral impact on the firms' competitiveness. Further, discarding the conventional dichotomy between incentive-based versus command-and-control type instruments, the results suggest to pursue a comprehensive policy mix, where standards, taxes and subsidies each capitalize on different transmission mechanisms. [ABSTRACT FROM AUTHOR]

The future market diffusion of alternative fuels in the passenger car sector is of great interest to both carmakers and policymakers in order to decrease CO 2 emissions. The decision to buy a car is not totally objective and only partly based on cost. For this reason, those modeling the future market evolution of cars powered by alternative fuels try to include behavioral and non-cost related aspects. This paper analyzes the integration of user behavior into market diffusion models and compares three models that include this aspect. The comparison comprises three parts: first, it compares the modeling approaches, then uses a harmonized data set to model the future market diffusion of alternative fuel vehicles, with and without behavioral aspects. The most important aspects of user behavior included in the models are the use of charging infrastructure, the limited model availability, the consideration of range anxiety as a hampering factor or the willingness-to-pay-more for alternative drivetrains as a supporting factor, as well as a distinction of users' driving distances. User behavior is considered in various ways, but always has a limiting effect on electric vehicle market diffusion. While a model that distinguishes individual users and driving distances stresses the high relevance of this aspect, it is considered less important in models with a more aggregated inclusion of user behavior based on logit functions. • Integrating user behavior into models reduces sales of alternative fuel vehicles. • High market shares of electric vehicles in 2030 (up to 50%) nonetheless. • User behavior important, but policies, energy prices and purchase prices also matter. • Individual effects of user behavior can be better analyzed in disaggregated models. • Aggregated models are less sensitive to changes in user behavior. [ABSTRACT FROM AUTHOR]

• Rethinking developed countries' contributions to carbon reduction through scenario analysis. • An environmental-extended multi regional input output approach was developed. • Global CO2 emissions would increase by 1.53% in the scenario without trades between germany and other countries. • Increase in emissions in developing countries was greater than in developed countries without free trade. • Germany's contributions in carbon emission reduction were underestimated. The pollution paradise hypothesis states that international trade shifts pollution from developed countries to developing countries, ignoring the positive effects that the participation of developed countries in international trade has on the reduction of carbon emissions. To evaluate a country's contribution to carbon reduction comprehensively, this paper constructed a framework for calculating carbon emissions in two trade scenarios using a multi-regional input-output model. It took Germany as an example, analyzing it at global, national, and sectoral levels. The main findings were as follows: firstly, Germany's contributions to the reduction of emissions may have been underestimated. Without Germany, global embodied CO 2 emissions would have increased by 1.53% on average during the research period. Secondly, Germany's participation in international trade contributed to carbon reduction in developing countries, particularly China and Russia. This was due to the lower intensity of Germany's carbon emissions. Finally, at the sectoral level, changes to carbon emissions in different trade scenarios mainly came from "manufacturing" and "electricity, gas and water supplies". As a result, corresponding policy suggestions were proposed. Studying Germany confirmed that trade protectionism did not benefit the environment and free trade was a better choice. However, more evidence is required to see whether this conclusion would be true for other countries. [ABSTRACT FROM AUTHOR]

In many industrialized countries, a significant number of buildings were constructed prior to any energy-related building construction standards. Today, single-family houses (SFH/pl. SFHs) from this time still have a comparably poor thermal quality. This paper aims to examine and model the incentive effects of the German energy retrofit funding schemes for owners of SFHs constructed shortly before the introduction of the first German thermal insulation ordinance in 1979. We develop a novel mixed-integer economic optimization model that determines the financially optimal energy retrofit configuration for owner-occupied SFHs. In a case study, we consider German framework conditions such as governmental incentives, standards, regulations, retrofit costs, and energy prices. We calculate economic burdens and benefits in 48 different retrofit scenarios for two representative SFHs constructed in the 1960s and 1970s. In the majority of cases, the return on investment is positive. For heating system retrofits, energy savings are comparatively small, but the cost-benefit ratios of retrofits are better than for measures on the building envelope. Overall, we find retrofits to decrease operational costs to between 15% and 62% of the initial value. The financial incentive effect of the German funding instruments can lead to financially optimal savings of CO 2 emissions in the range of 82–94%, however our findings show that the conditions of the German funding programs are not designed to maximize CO2 savings per funded euro. We show that the funding invested to reduce the annual tons of CO2 ranges from 493 € to 3747 € in our case study. [Display omitted] • Economic optimization model for energy retrofit measures for single-family houses. • Case study of German buildings shows positive return on investment for most retrofits. • The funding invested to reduce the annual tons of CO 2 ranges from 493 € up to 3747 €. • Public financial retrofit incentives minimize energy demand but not CO 2 emissions. • The approach is transferable to buildings and framework conditions in other countries. [ABSTRACT FROM AUTHOR]

Defossilizing the energy and industrial systems and transformation towards a circular economy have versatile impacts on the availability and demand of alternative resources. However, systematic analyses on these interrelations are very sparse. Thus, this paper investigates the interlinkages between the energy transition and the transformation towards a circular economy in Germany. The study is based on material flow analysis models of the steel and cement industries as well as the coal and lignite power plants in order to depict a comprehensive description of the material, energy and emission flows of these sectors and their interdependencies. The analyses prove the inherent interrelation between energy transition and circular economy. On the one hand, energy transition does not only bear various techno-economic challenges and have substantial effects on the production costs, but it also affects the availability of secondary materials. For instance, the coal phase-out and the introduction of green steel imply that the current supplies of blast furnace slag, fly ash and FGD gypsum cannot be maintained. On the other hand, circularity approaches can also influence the energy transition. For example, banning single-use plastics and increasing recycling rates of plastics can deprive the cement industry from significant amounts of energy resources with low-carbon footprint. Contrariwise, CO 2 recycling can promote the energy transition by means of mitigating CO 2 emissions via carbonation. Therefore, the study can help policymakers to understand the indirect effects of existing and future policies. Also, it can help to develop future strategies to handle associated impacts and avoid material shortages. [ABSTRACT FROM AUTHOR]

Electric vehicles as part of corporate fleets play a key role in reducing CO 2 emissions. However, business practice has shown that employees often refrain from using these newly procured fleet vehicles. The aim of this paper is therefore to explain the drivers and barriers of acceptance of electric vehicles on the employee's level. Based on a Grounded Theory approach, the authors extracted five main determinants from interviews with 16 experts. They were cross-checked with the literature including technology acceptance literature and electric vehicle research. To understand the dynamics of acceptance, panel data was collected in a longitudinal study with three waves in Germany. The panel data was analyzed using partial least squares (PLS) path modelling. Results show that employees' environmental concern as an attitudinal factor is the only short-term determinant triggering the first electric vehicle usage. Later, the influence of environmental concern disappears, while the impact of product-related determinants, such as enjoyment, ease of use, perceived risks, and relative advantage increases. Furthermore, a mediating effect of enjoyment emerges between ease of use on the intention to use an electric vehicle. Several important implications for decision-makers in management and policy are deduced to support short- and long-term usage of electric vehicles in corporate fleets. • The study explains the dynamics of acceptance of electric vehicles in fleets. • Five determinants of acceptance were identified based on a Grounded Theory approach. • The dynamics of acceptance was analyzed using data from a longitudinal study. • At first, only environmental concern triggers employees' behavioral intention. • Later, enjoyment, ease of use, perceived risks, and relative advantage become significant. [ABSTRACT FROM AUTHOR]

Germany 2050: For the first time Germany reached a balance between its sources of anthropogenic CO2 to the atmosphere and newly created anthropogenic sinks. This backcasting study presents a fictional future in which this goal was achieved by avoiding (∼645 Mt CO2), reducing (∼50 Mt CO2) and removing (∼60 Mt CO2) carbon emissions. This meant substantial transformation of the energy system, increasing energy efficiency, sector coupling, and electrification, energy storage solutions including synthetic energy carriers, sector‐specific solutions for industry, transport, and agriculture, as well as natural‐sink enhancement and technological carbon dioxide options. All of the above was necessary to achieve a net‐zero CO2 system for Germany by 2050. Plain Language Summary: Here a net‐zero‐2050 Germany is envisioned by combining analysis from an energy‐system model with insights into approaches that allow for a higher carbon circularity in the German system, and first results from assessments of national carbon dioxide removal potentials. A back‐casting perspective is applied on how net‐zero Germany could look like in 2050. We are looking back from 2050, and analyzing how Germany for the first time reached a balance between its sources of CO2 to the atmosphere and the anthropogenic sinks created. This would consider full decarbonization in the entire energy sector and being entirely emission‐free by 2050 within three priorities identified as being the most useful strategies for achieving net‐zero: (a) Avoiding‐ (b) Reducing‐ (c) Removing emissions. This work is a collaboration of interdisciplinary scientists with the Net‐Zero‐2050 cluster of the Helmholtz Climate Initiative HI‐CAM. Key Points: The net‐zero system shows that for countries like Germany, avoiding CO2 emissions was the largest contribution to achieve net‐zero CO2With the three strategies of emissions avoidance, reduction, and removal, Germany has achieved its net‐zero CO2 goal for the first timeIn addition, to natural sink enhancement carbon dioxide removal (CDR) options, technological CDR measures combined with geological CO2 storage were necessary to reach net‐zero CO2 [ABSTRACT FROM AUTHOR]

The transparency and open availability of energy system models and their input data are of particular importance due to their increasing complexity and policy relevance. In recent years, a large number of model-based scenario analyses have been carried out. These analyses are based on diverse model approaches and lead to a rather broad range of results, which due to different data structures and mathematical approaches are hardly directly comparable. In this paper, detailed and harmonized scenario input parameters are the basis of a systematic model experiment including four electricity system models. In the following, the different model approaches are classified and their respective results are discussed transparently. Consequently, differences in results can be interlinked directly with model properties. The results are compared focusing on a selection of output parameters, such as investment and dispatch decisions in flexible power plants, storage dispatch, wholesale electricity prices, CO 2 emissions and generation adequacy in hours with critical supply situations in Germany until 2030. Differences in the results are traced back to conceptual differences as the models can be distinguished not only with regard to their mathematical approaches, but also to their level of detail. Results indicate that next to the differences of the mathematical approaches (i.e., linear optimization vs. agent-based simulation), the myopic foresight perspective (e.g., rolling planning algorithm with 24- and 36-hours loops vs. perfect foresight in a closed loop for one year) are decisive for the range of obtained results. • Systematic comparison of four electricity system models. • Analysis of differences in model results for a future German power system. • Foresight perspective and mathematical approach influence model outcomes. • Investments of at least 2.6 GW seem profitable in Germany in 2030. • Need for 12 GW of additional flexibility to ensure generation adequacy in 2030. [ABSTRACT FROM AUTHOR]

District heating is expected to play an essential role in the cost-effective decarbonisation strategy of many countries. Resource-optimised management of district heating networks depends on a wide range of factors, including demand forecasting, operational flexibility, and increasingly volatile market conditions. However, traditional operations often still rely on static models and rather simple heuristics, while holistic optimisation requires dynamic cross-domain interoperability to allow the consideration of all these factors. This paper demonstrates a proof-of-concept for a knowledge graph based optimisation problem to minimise total heat generation cost for a district heating provider. The optimisation follows a hierarchical approach based on a merit-order principle and is embedded in a model predictive control framework to allow the system to incorporate most recent information and react to disturbances promptly. A detailed sensitivity study is conducted to identify key model parameters and assess the impact of anticipated changes in regulation and market conditions. Simulation-based optimisation is used to determine the short-term heat generation mix based on data-driven gas consumption models and day-ahead forecasts for the network's energy demand and grid temperatures. Seasonal autoregressive integrated moving average models with exogenous predictor variables are found to be sufficiently accurate and precise. The effectiveness of the approach is demonstrated for a case study of an existing heating network of a midsize town in Germany, where a reduction of approximately 20% and 40% compared to baseline operational data is obtained for operating cost and CO 2 emissions, respectively. [Display omitted] • Developed heat generation optimisation framework for district heating providers. • Identified key cost drivers and market dynamics using a detailed sensitivity analysis. • Developed high accuracy time series forecasting models for key input variables. • Assessed optimisation effectivity using a German municipal utility case study. • Improvement potential for operational cost and CO 2 emissions both exceed 20%. [ABSTRACT FROM AUTHOR]

Developing more effective mitigation strategy to achieve the carbon reduction targets set by the Paris Climate Agreement requires to more comprehension of the driving factors of the decline in carbon emissions. Production-based and consumption-based carbon emission in Germany declined by 2.8% and 8.5% from 2000 to 2015, respectively. In this work, the key drivers behind decline in carbon emission in Germany is explored by combing the multi-regional input-output and structural decomposition analysis. The results show German carbon emissions has been undergoing structural changes. Although its production-based and consumption-based emission declined, German carbon footprint embodied in exports increased, and its share in the production-based carbon footprint also increased. Germany's embodied emission exports to emerging countries increased, although Germany's embodied carbon exports remained mainly concentrate in developed countries, especially in EU (over 40%) and USA (∼10%). The decomposition results revealed that economic scale effect was the leading contributor to increase in carbon footprint in Germany's trade, followed by the industrial structure effect of final demand. The effects of production structure on German's exports was less than its imports. The carbon intensity coefficient was the most significant factor of decreased carbon emission. Generally, the decreasing effect of carbon intensity coefficient exceeded the increasing effect of economic scale, which lead to carbon reduction. The example of Germany shows that improving carbon emission efficiency and optimizing production structure can reduce carbon emission without lowering economic growth. [ABSTRACT FROM AUTHOR]

This paper aims to investigate the causal relationship among renewable energy technologies, biomass energy consumption, per capita GDP, and CO 2 emissions for Germany. We constructed an innovative algorithm, the Quantum model, and applied it with Machine Learning experiments – through a software capable of emulating a quantum system – to data over the period of 1990–2018. This process is possible after eliminating the "irreversibility" of classical computations (unitary transformations) by making the process "reversible". The empirical findings support the powerful role of biomass energy in reducing carbon dioxide emissions, although the effect of renewable energy technology displays a much stronger magnitude. Moreover, income remains an important determinant of environmental pollution in Germany. • An innovative Machine Learning algorithm (the Quantum model) has been constructed and applied. • The empirical findings support the powerful role of biomass energy in reducing CO 2 emissions. • GDP represents an important determinant of environmental pollution in Germany. [ABSTRACT FROM AUTHOR]