arXiv subjects

Ricardo Fernandes

Publications and source records attributed to Ricardo Fernandes.

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↗

arXiv2024

Managing CO2 under global and country-specific net-zero emissions targets in Europe

The European Union (EU) aims to reach carbon neutrality by 2050. This requires capturing CO2, eventually transporting it to different regions, and either converting it into valuable products or sequestering it underground. Although the target is set for the entire EU, in practice, most of the governance and strategy to attain it remains in the individual member states. Previous literature modelling how Europe can achieve carbon neutrality has either considered only a global CO2 limit or used coarse spatial and temporal representation without proper network modelling. Here, we use a highly-resolved open model of the European sector-coupled energy system, PyPSA-Eur, to explore the impacts of imposing net-zero emissions globally for the entire EU versus imposing carbon neutrality for each country. Forcing net-zero emissions in every country increases system cost by 1.4%, demands varied CO2 prices, and triggers higher investment in direct air capture and renewable capacities. Furthermore, in both scenarios, a significant portion of the captured CO2 is transported across Europe, either directly via CO2 pipelines or indirectly via solid biomass or synthetic methane gas, methanol, and oil. Our research enables quantifying the impact of following a collaborative or self-sufficient carbon management strategy to attain carbon neutrality.

physics.soc-ph↗

arXiv2023

From disformal electrodynamics to exotic spacetime singularities

We study different types of spacetime singularities which emerge in the context of disformal electrodynamics. The latter is characterized by transformations of the background metric which preserve regular (non-null) solutions of Maxwell equations in vacuum. Restricting ourselves to the case of electrostatic fields created by charged point particles along a line, we show that exotic types of singularities arise.

gr-qc↗