[en] Anthropogenic climate change is one of the greatest challenges of this century: The consequences of global warming above 1.5°C seriously threaten our civilization. Climate scientists thus agree that the release of greenhouse gases (GHG) to the atmosphere must be reduced by about 50% until 2030 and reach net-zero until 2050. The manufacturing industry is one of the main emitters of GHG in the European Union. This is caused by its reliance on fossil fuels as energy carrier and feedstock. This thesis investigates opportunities for important industrial processes to switch to less GHG-intensive energy carriers. The analysis incorporates technical, economic and behavioural aspects of energy carrier selection. The insights gained inform a bottom-up energy system model, which is used for policy advice on national and European level. One of the main conclusions of this thesis is that vast technical potentials for fuel switching exist and that it may be a substantial pillar of early decarbonisation. The realization of these potentials however requires drastic changes to economic conditions.

[en] This REFOPLAN project analyses the technologies for the future CO${}_2$-neutral generation of process heat for 13 industrial sectors. This means replacing fossil fuels with energy carriers based on renewable energy sources such as electricity or PtG/PtL fuels including hydrogen or synthetic methane. The study takes a broad approach and covers the metal and mineral industries as well as steam generation as a cross-sector technology. The study examines the use of CO${}_2$-neutral alternative technologies for 34 selected applications such as the "continuous heating of flat or long steel". The study looks at both the current state of the art and future potentials of the various CO${}_2$-neutral alternative technologies. The aim is to take a holistic view, taking into account technical, economic and ecological criteria. In addition, recommendations are derived as elements of an overarching strategy for the transformation towards CO${}_2$-neutral process heating.

[en] This report presents marginal abatement cost curves (MACCs) for greenhouse gas emissions in the stationary part of the European Union Emissions Trading Scheme (EU ETS) for the years 2030 and 2040, covering all 31 countries participating in the EU ETS (including the UK) and all relevant activities/sectors with the exception of the aviation sector. The development of the EU ETS-specific MACCs was based on a system of two models: Enertile, a model to optimise the European electricity system and FORECAST-Industry, a bottom-up simulation model for the industrial sectors including refineries. In addition to a base scenario, three sensitivity analyses were carried out to verify the robustness of the results. This report contains the developed MACCs, the results of the sensitivity analyses as well as a detailed description of the models used and assumptions made to allow the interpretation of the MACCs. In addition, the results were compared with other studies and the main methodological and substantive challenges in the development of MACCs are discussed.

[en] This document presents the final report of the project ''Efficiency and effectiveness of the EU ETS - extended analyses (EU-ETS 6)''. The project aims to deliver further contributions for the evaluation of the efficiency and effectiveness of the European Emission Trading System (ETS). In doing so, the project provides advice to the Federal Environmental Agency (UBA), as implementing authority, and the Federal Ministry for the Environment, Nature Conservation, Building and Nuclear Safety (BMUB) as the competent ministry, on methodological aspects of ex-post assessments and lessons learned for ex-ante analyses. The project builds on a previous study, titled ''Evaluierung und Weiterentwicklung des EU-Emissionshandels (EU-ETS- 5)''. The current project focusses on methodological approaches for an ex-post assessment of the effects of the EU ETS and introduces different ''Tier'' levels reflecting different scopes of complexity. The core of each analysis is to compare estimated abatement costs under the EU-ETS with cost estimates for a fictitious ''alternative policy scenario'' that aims to achieve the same total abatement but does not provide the flexibility of trading allowances. Case studies are conducted based on marginal abatement cost curves derived from a partial equilibrium model and from bottom-up models for the industry and the electricity sector respectively. Besides the different modelling approaches, the case studies differ essentially in the design and assumptions chosen with respect to the i) counterfactual scenarios, ii) alternative policy scenario, iii) sector detail, iv) abatement costs and CO₂-prices and v) temporal perspective. An efficiency analysis of the ETS always implies a trade-off between breadth and depths of the analysis. Yet, the case study analyses all reveal efficiency gains for the ETS compared to an alternative policy. For example, the Tier 2 analysis -covering a medium level of detail - investigated different sector disaggregation and different time frames for the 2^nd trading period and concluded that 15% to 50% of abatement costs were saved within the ETS compared to the alternative policy scenario. Emissions trading thus leads to important efficiency gains according to these estimates.

[en] Hydrogen and its derivatives are important components to achieve climate policy goals, especially in terms of greenhouse gas neutrality. However, there is an ongoing controversial debate about the applications in which hydrogen and its derivatives should be used and to what extent. In addition to the ambitiousness of climate targets, a decisive criterion here is the price of hydrogen and its associated ability to compete with other options such as direct electrification. To address this issue, this study aims at developing a methodological approach to determine the demand for hydrogen and its derivatives as a function of possible hydrogen price pathways and then applying it to Germany under the goal of Germany becoming greenhouse gas-neutral in 2045. The price elasticity of hydrogen demand in the individual application areas of industry, transport and energy conversion is determined using techno-economic, agent-based simulation models or optimization models. These models map the alternative options for achieving the climate goals and evaluate these using economic criteria. For instance, whether it makes more sense economically to use electric cars or fuel cell cars depending on the hydrogen price pathways, which are defined exogenously. For certain areas - building heat and international air and maritime transport - the results of other studies are used rather than modeling. One key result is that so-called no-regret applications are a very important driver of the demand for hydrogen. These are applications for which, based on current knowledge, there are hardly any other economically-attractive technology options available for achieving Germany’s ambitious greenhouse gas reduction targets. The lack of alternatives means they are therefore price-inelastic to a large extent. These concern, in particular, the material and energy use of hydrogen in certain applications in industry (steel and basic chemicals). The calculations show that demand here will amount to 250 TWh in 2045, which is roughly 10% of the current final energy demand in Germany. Around 20 GW of electrolysis capacity would have to be installed in Germany alone just to meet German demand assuming that one third is produced domestically, which represents an enormous challenge. To put this in perspective: At the beginning of 2022, only 0.5 GW of electrolysis capacity was installed worldwide (IEA 2022). Developing hydrogen production is time-consuming and capital-intensive. Further, the need for a rapid rate of expansion is often emphasized if the set political targets to develop a hydrogen economy are to be reached (see Hydrogen Council (2021), Hydrogen Council (2022), IEA (2021b)). International air and maritime transport also show high, price-inelastic demand for synthetic fuels to reduce greenhouse gases (209 TWh in 2045). In this study, it is assumed that this demand is covered by biogenic sources. Because demand in these sectors is primarily for hydrogen and biogenic synthesis products, the implication is that cost-favorable hydrogen is not likely to be available in other sectors. Especially in other transport applications (cars, trucks, buses, rail and national aviation and shipping), for which direct electrification is often an alternative, the calculations show that hydrogen will only be used on a larger scale if it is available at a very low price. This is only the case at wholesale hydrogen prices of less than 90 Euro/MWh in 2045, or even significantly lower, depending on the application. This also applies to the use of hydrogen for energy in industry to generate steam and heat, and even more so for the sector of building heat. At a price of 50 Euro/MWh, the analyses yield a total demand for hydrogen of 476 TWh in 2045. However, price levels below 90 Euro/MWh and even lower are hardly to be expected. Even pure cost considerations show that this only seems feasible at present at very favorable locations around the world. Transport costs, profit margins, capital costs reflecting country risks, distribution costs, R&D costs etc. still have to be added to the production costs shown in these studies. Furthermore, the production quantities at very favorable locations are limited and, based on the information currently available, will not be sufficient to meet the emerging global demand. This means having to resort to sites with higher production costs as well. Based on current knowledge, it can be assumed that market prices for hydrogen in 2045 will be significantly above 90 Euro/MWh. It does not seem reasonable, therefore, to pursue larger-scale support of hydrogen use in the sectors of building heat, land-based transport or energy use in industry. There may be exceptions to this in certain niche applications. For example, providing building heat if there is already hydrogen demand at a nearby industrial site. In the energy conversion sector, there is an interesting wholesale price range (from 130 to 90 Euro/MWh), in which the demand for hydrogen is relatively price-elastic. This is related to the fact that options to balance supply and demand are necessary for the targeted expansion of renewable energies. Here, the options of using hydrogen storage and reconversion into elec-tricity compete, among others, with options to increase the flexibility of demand. The flexibility options here include heat pumps, heat networks or electric vehicles. In addition, there is the option to use other storage options or to deploy even more renewables and accept the risk of their greater curtailment. In future, the prices for hydrogen will co-determine the extent to which it is used in the future. The results for 2030 show that hydrogen demand will not yet be very high at this time (slightly more than 40 TWh). This hydrogen demand will be dominated by specific industrial applications. Support should focus on these in the coming years. Demand in 2030 only increases sig-nificantly if very low wholesale prices are assumed, which does not seem very realistic at present.