Conference Agenda

In view of global climate change, it is important to save energy and therefore emissions in all sectors. The German building sector is particularly lagging behind the savings targets. While single-family homes are increasingly being renovated and PV systems installed, it is particularly difficult to implement such measures in multi-party buildings, especially if they are occupied by low-income earners. In this context, we examine how student dorms can be transformed in terms of energy efficiency taking energy saving measures. The focus of the investigation was on the preferences and objective systems of student occupants. In order to ensure a reflective and systematical investigation, Value-Focused Thinking was applied in a workshop with 50 occupants of a student dorm in Aachen, Germany. The final aggregated fundamental objectives, which were developed by the workshop participants in group work as elementary for the joint implementation of energy-saving measures, are: feasibility, profitability, health, ecological sustainability, comfort, social harmony. Using the Analytic Hierarchy Process approach for a Multi-Criteria Decision Analysis, these fundamental objectives were weighted by the participants. Fulfilling these fundamental objectives would ensure that the initiatives are not only practical and economically viable, but also enhance the well-being and environmental responsibility of the occupants. By prioritizing these objectives, student dorms can foster a culture of sustainability that resonates with students' values and daily lifes, ultimately leading to more successful and widely adopted energy saving practices.

The spatial distribution of future renewable capacities is a key determinant for the develop-ment of appropriate grid expansion plans. This is particularly relevant for onshore wind ener-gy. Thereby, existing studies mostly extrapolate the future installations based on existing ca-pacities and available sites. As wind farm projects are developed by private (or state-owned) companies, the economic rational of investing at specific sites deserves more attention. Therefore, the present contribution develops a model of economic choice for wind invest-ments based on site-specific computations of the achievable net present value taking into consideration the land availability at the regional level. Thereby the site-specific investment decisions are modeled as (partly aggregated) discrete choices. The net present value is computed from investment costs and expected yields, which can be estimated based on wind speed time series and power curves. Available land can be identified by excluding settlement, infrastructure, and nature conservation areas with appropriate buffers as well as sites with topographically unsuitable profiles. The model is formulated as a nested logit model which captures the interdependencies between choices on two levels: the probability of investment in a particular region on the first level and the probability of installing a specific turbine type there on the second level. In an application for Germany with the target capacities of the German Renewable Energy Act, the model delivers a spatial distribution of the capacities on NUTS 3 level. The model also enables the derivation of the necessary compensation level and the most frequently installed turbine types.

Policy measures significantly influence the development of renewable fuel supply chains (RFSC) by determining the demand, technology selection, and infrastructure evolution necessary for providing renewable fuels for the transport sector. Such policies, including mandates for renewable fuel shares, targets for reducing GHG intensity of fuels, and carbon pricing measures on supplied fuels, are pivotal for encouraging the transport sector towards climate neutrality. However, comprehensive assessments are needed to understand the impact of these measures on the overall GHG targets and costs of RFSC, including the potential contribution of the different transport subsectors and the effect on fuel supply chains, as well as their interrelations.

Our research aims to analyze policy measures that promote climate neutrality within the transport sector by examining their influence on the design of RFSCs. We employ a multi-period mixed-integer linear programming model that enables the evaluation of policy frameworks based on total net present costs and GHG emission savings. Through identifying Pareto-efficient solutions, we investigate the trade-offs between the two objective functions. Additionally, factorial analysis reveals the impacts of contributions of policy measures on the design of RFSCs. The results from the Pareto frontier show that higher cumulative GHG emission savings result in higher net present costs. Furthermore, the study indicates that an earlier supply of renewable fuels in the transport sector leads to higher GHG emission savings. In conclusion, this analysis offers insights into how policy measures can influence the renewable fuel supply trajectory and contribute to achieving climate neutrality goals in the transport sector.

In our work we identify and evaluate transformation pathways for a sustainable chemical industry in Germany in 2045. Such transformation scenarios include 1. a greenhouse gas-neutral energy supply and 2. the diversification of carbon-based raw materials, e.g., CO2 from direct air capture, biomass, and plastic waste. Different technologies as well as availability and prices of resources and feedstocks are considered in an investment optimizatiopin model. The model allows us to evaluate technology paths with respect to operational and investment cost, environmental effects, and societal impacts (e. g. measured by number of jobs and value added). Technological paths are mapped for the production of conventional chemical base materials, primarily aromatics and olefins, and includes their synthesis via chemical recycling, Fischer-Tropsch processes, and methanol derivatives. Biomass streams and plastic waste play a primary role as sustainable carbon sources that are used for synthesis gas and pyrolysis oil production, respectively. We explicitly model synergies in existing and future Verbund site configurations.

In the evaluations, we analyse technological paths will evolve under different regulatory scenarios. We consider e. g. waste and biomass potentials as well as operational and investment costs along with regulatory and market factors like electricity cost, GHG cost and CCS budgets.

Scenario evaluation includes an assessment of impacts for chemical industry and economy by estimating e. g. value added, jobs created as well as investments and operation cost of the optimized value chains. Additionally, we analyse resulting infrastructure requirements, especially for scenarios with high value added.