arXiv subjects

Sina Kalweit

Publications and source records attributed to Sina Kalweit.

4 recordsLinked to original sources

arXiv2026

Exploring carbon dioxide removal strategies to help decarbonise Europe using high-resolution modelling

The electrification of energy demand across sectors, powered by solar and wind generation, is the best strategy for achieving carbon neutrality. Carbon dioxide removal (CDR) strategies are also expected to play a crucial role by providing net-negative emissions that can offset residual CO2 emissions, including those from cement manufacturing. While previous studies have assessed the role of CDRs in Europe's decarbonisation, most either focus solely on combinations of biogenic point-source capture and direct air capture (DAC) coupled with underground sequestration, or consider multiple CDR strategies at low spatial and temporal resolution, thereby limiting the representation of linkages amongst technologies. In this study, the sector-coupled European energy system model PyPSA-Eur is extended to include afforestation, perennialisation, biochar, and enhanced rock weathering (ERW) as additional CDR strategies. Using this model with a 3-hourly resolution and a network comprising 90 nodes, results show that a climate-neutral energy system equipped with these CDR strategies is 9% less expensive. Afforestation, perennialisation, and ERW potentials are fully utilised across regions, whereas biochar is not selected due to limited solid biomass feedstock being allocated to other higher-value processes. Furthermore, when these CDR strategies are combined with underground sequestration and a continental CO2 transport network, DAC is no longer required to achieve climate neutrality in Europe.

physics.soc-ph↗

arXiv2026

Near-optimal solutions for carbon capture, conversion, storage, and removal strategies

Achieving climate neutrality in Europe requires rapid electrification alongside carbon management strategies for residual emissions. Existing analyses of the European energy system often focus on collocated carbon capture and geological sequestration, with limited attention to the interactions among carbon capture and utilization, transport, sequestration, and diverse carbon dioxide removal (CDR) options. Moreover, existing literature focuses on discussing the optimal, neglecting that near-optimal solutions might provide very different system configurations at a marginal higher cost. Here, we integrate afforestation, biochar, enhanced rock weathering, and perennialization into a sector-coupled European energy system model (PyPSA-Eur) clustered to 39 nodes with 750 aggregated time steps. We explore their contributions using a Modelling to Generate Alternatives (MGA) approach. The approach combines minimization, maximization, and random vectors to explore the near-optimal solution space for up to 5% increased total system costs. Our results show that, in a carbon-neutral system, multiple configurations of carbon management options can achieve net-zero emissions with only marginal cost increases. We find that a 5% total system cost increase is sufficient to accommodate the full spectrum from zero to full deployment of the individual CDR options, as well as a wide range of synthetic fuel use across different fuel types. Increased reliance on CDR options offers no clear cost advantage compared to greater utilization of synthetic fuels.

physics.soc-ph↗

arXiv2025

Shifting burdens: How delayed decarbonisation of road transport affects other sectoral emission reductions

In 2022, fuel combustion in road transport accounted for approximately 21% (760 million tonnes) of CO2 emissions in the European Union (EU). Road transport is the only sector with rising emissions, with an increase of 24% compared to 1990. The EU initially aimed to ban new CO2-emitting cars by 2030 but has since delayed this target to 2035, underscoring the ongoing challenges in the push for rapid decarbonisation. The pace of decarbonisation in this sector will either ease or intensify the pressure on other sectors to stay within the EU's carbon budget. This paper explores the effects of speeding up or slowing down the transition in road transport. We reveal that a slower decarbonisation path not only drives up system costs by 126 billion Euro/a (6%) but also demands more than a doubling of the CO2 price from 137 to 290 Euro/tCO2 in 2030 to trigger decarbonisation in other sectors. On the flip side, accelerating the shift to cleaner transport proves to be the most cost-effective strategy, giving room for more gradual changes in the heating and industrial sectors, while reducing the reliance on carbon removal in later years. Earlier mandates than currently envisaged by the EU can avoid stranded assets and save up to 43 billion Euro/a compared to current policies.

physics.soc-ph↗

arXiv2025

Endogenous transformation of land transport in Europe for different climate targets

Road transport is responsible for about a quarter of Europe's greenhouse gas emissions, making its transformation a crucial part of Europe's overall decarbonization goals. Current European policies promote decarbonizing the transport sector and passenger car sales show an increased adoption of electric vehicles. Full electrification of land transport will significantly increase the average electricity demand but the use of smart charging and vehicle-to-grid could provide additional flexibility to balance wind and solar generation. In this study, we find cost-optimal transition pathways of the European land transport sector embedded in the sector-coupled open energy model PyPSA-Eur. We consider fossil-fueled, hydrogen-fueled, and electric cars using a 3-hour time resolution for a full year and covering 33 interconnected European countries. We analyze a transition path from 2025 to 2050 under different carbon budgets corresponding to a 1.7{\deg}C and 2{\deg}C temperature increase. Our results show that rapid electrification of road transport reduces the total system cost, even in the absence of climate targets. We see a clear preference for rapidly decommissioning internal combustion engine vehicles and using electric vehicles in all countries and under all carbon budgets. Allowing smart charging of electric vehicles decreases the total system cost by 1.6% because it reduces the need to install stationary batteries by almost 40%.

physics.soc-ph↗