Climate change is one of the pressing issues of our time. In order to limit global warming, the greenhouse gas emissions (GHG) need to be reduced drastically over the next decades in all sectors. A special role is played by the power sector, because it is the one responsible for most GHG emissions and because its costs for decarbonization are rather low. Consequently, national policies aim at reducing GHG emissions by supporting the expansion of renewable energy sources for electricity production (RES) and initiating a coal phase-out (CPO). European policymakers have implemented the EU Emissions Trading Scheme (EU ETS), a mechanism for pricing GHG emissions in the power and industry sector across Europe that incentives carbon mitigation. This dissertation investigates how national and European policies affect the power market and especially its GHG emissions and examines how these policies interact. This dissertation shows that RES, in addition to the short-term, well-studied, merit order effect, which reduces power wholesale prices, also have long-term effects on electricity markets. The long-term effect describes the impact that RES have on investment decisions into conventional technologies, which are reduced by over 8 GW in Germany. This indicates that the power market adapts to the expansion of RES. With regard to the GHG mitigation of RES, it is shown that currently RES contribute substantially to the mitigation of GHG emissions. Because wind power substitutes coal power, it has a significantly higher potential to avoid GHG emissions than solar power in Germany. Provided wind stays favorable in the future, this portends from a climate perspective that politics should focus on the expansion of wind. It further justifies higher support schemes for wind than solar energy. The impact of the CPO on the GHG emissions depends strongly on legal implementation. If no further actions are taken, the demand for emission decreases, because existing emitters leave the market and the price drops to 0 EUR/t. The EU ETS loses its incentive effect and the emissions are realized elsewhere since the cap remains the same and is fully exploited. Therefore, alongside the CPO, emission certificates have to be deleted in order to maintain the incentive effect of the EU ETS. Furthermore, the loss in valuation of the German coal power plants depends strongly on the time of the CPO. Given high expected emission prices and the expansion of RES, coal-fired power plants cannot be operated economically advantageously in the long-term. Therefore, no devaluation is expected if power plants are phased out in 2038 or shortly before and hence, those power plants should not receive any compensation. Additionally, this dissertation shows that the EU ETS is a strong European policy that provides sufficient incentives to meet the European climate targets in 2030 and to realize the necessary expansion of RES. However, if national RES development paths are implemented, this leads to higher overall costs but also very different profitability of RES in each country This is because countries with high ambitions regarding the expansion of RES face self-marginalization effects, which reduces the revenues for RES due to the merit order effect, and increases the level of support needed for them to expand. In contrast, countries with low RES ambitions have little or no need of support schemes but benefit from low prices in the EU ETS due to strong RES expansion in countries with high ambitions. Summarizing, this dissertation demonstrated that both national and European policy contribute to the decarbonization of the European power sector. However, the different policies interact. This can have negative impacts, which indicates that a greater harmonization of policies is necessary. Further research should develop comprehensive policy approaches and discuss possible challenges.

Transportation in Sweden currently accounts for one-third of domestic GHG emissions. Thereof more than 90 % are allocated to road traffic with passenger cars being the largest contributor. Hence, the Swedish government adopted stringent climate policies to cut transport emissionsby 70 % (compared to 2010) latest until 2030. Electrification is seen as one of the key strategies to mitigate climate change and to accomplish set climate goals. Hence, estimation and quantification of electric vehicle life cycle carbon footprints is of major interest to understand their environmental performance. As part of this study lifetime burdens for gasoline, diesel and battery electric vehicles were contrasted. Nominal end of life was assumed to be reached after 200.000 km. The life cycle inventory was conducted based on market and literature data and by employing the open-source LCA tool carculator. Impacts on material resources were assessed by various materialization models for vehicle glider, combustion powertrain and electric powertrain. Additional impact categories such as formation of fine particles, freshwater use and terrestrial ecotoxicity were included. Results showed that lifetime carbon footprints of electric vehicles in Sweden are 45-51 % lower compared to conventional diesel and gasoline drives. Per driven kilometer, electric vehicles caused 137,46 g CO2-eq./km, diesel vehicles 249,28 g/km and gasoline vehicles 282,75 g/km. Savings of electric drives mainly originate from vehicle operation (zero tailpipe emissions) and low carbon electricity generation (predominantly hydropower, nuclear energy and wind energy). Lifetime battery charging according to the Swedish energy system was found to provoke 1,03 t of GHG emissions. This is ten times lower compared to average EU loads. Modeling results for electric vehicle manufacturing disclosed a total carbon footprint of 17,63 t CO2-eq. with a significant portion of 5,99 t originating from lithium-ion batteries. This is 57-63 % higher than estimated production footprints for fossil fuel vehicles with the same amount of 8,63 t CO2-eq. allocated to the glider. However, performed sensitivity studies revealed significant potential to cut emissions from battery manufacturing with transition to European sites. Replacement and conversion of vehicles from the Swedish fleet was assessed according to both, a fixed lifetime perspective of 200.000 km and year-by-year scenario models. Three different paths projecting development of the vehicle stock until 2030 are presented. Results of this work showed that vehicle conversion offers potential to save about 1.191 kg of material resources (thereof 728 kg ferrous metals, 104 kg aluminum, 149 kg plastics and 210 kg other materials). Corresponding savings in production emissions comprise 8,63 t CO2-eq. through reuse of the vehicle glider. From a nationwide perspective, up to 34 % of annual GHG emissions and up to 60 % of the annual material demand could be saved. Results further suggest a target value of around 3,8 millionelectric vehicles by 2030 to achieve aspired emission limits. / Kurzzusammenfassung - Siehe angehängtes Dokument / <p>NOT KTH STUDENT (INTERNSHIP AT ITRL)</p> / International collaboration with University of Stuttgart