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Third-generation biofuels are currently a promising alternative for energy production, since electricity prices have risen sharply and the search for alternative energy sources to fossil fuels has become a necessity. The use of the anaerobic digestion process for the production of biomethane from microalgae has been studied over the years and has reached a certain degree of maturity, becoming the most straightforward way to obtain energy from microalgae without the need for a previous drying or extraction phase, thus eliminating the costs associated with these operations. Microalgae also show a high potential to grow in different media, including wastewater, as well as a high capacity for nutrient absorption and carbon dioxide fixation, which aid in decarbonization. These characteristics, combined with biomethane production, can contribute to achieving a satisfactory bioenergy production in a circular economy model. Peer reviewed 2 Tablas

Published online: 26 November 2024 This study investigates the relationships between social and political trust and views on energy affordability, which are crucial for promoting sustainable energy practices. The findings indicate that social and especially political trust are negatively correlated with perceptions of energy affordability. The study also finds that the probability of being highly concerned about energy affordability is declining in the level of trust, especially in countries, as those in Southern European, that prioritize energy affordability. These findings confirm the critical role of trust in effective energy policies, fostering public support for transitions to sustainable energy systems. The study recommends that policymakers enhance transparency, accountability, and public engagement to build trust, thereby improving perceptions of energy affordability and supporting sustainable energy transitions.

The increase of energy in the climate system caused by anthropogenic climate change is expected to disrupt predictable weather patterns and result in greater temperature extremes.1,2 As a result of these climate shifts, El-Niño Southern Oscillation (ENSO), which drives predictable periods of hot/dry and cool/wet across the Pacific, is expected to increase in variability and magnitude.3 These changes will significantly impact ectotherms, whose performance across a range of behaviors is dependent on local environmental temperatures.4 As such, we must understand the way individuals experience climate conditions and how changes in their body temperature (Tb), whether through climate or modification of their thermoregulatory mechanisms,5 affect their performance. Laboratory studies have shown that estuarine crocodile (Crocodylus porosus) diving and swimming performance is reduced above 32°C-33°C,6,7,8 temperatures commonly exceeded across their natural range. By monitoring Tb and diving activity in 203 free-ranging estuarine crocodiles over 15 years, we show that the Tb of crocodiles has increased alongside rising air temperatures since 2008, reflecting the climatic shifts caused by the ENSO cycle. As ambient temperatures rose, crocodiles experienced more days close to critical thermal limits (32°C-33°C), at which temperatures the duration of dives was reduced and the prevalence of active cooling behavior was elevated. This study demonstrates that crocodiles are susceptible to multi-year fluctuations in ambient temperature, which requires them to undertake concomitant changes in behavior. They are already close to their physiological thermal limit, but the impact of future predicted rises in temperature remains unknown.

Optimal power flow (OPF) plays a crucial role in addressing asymmetric operational problems of bipolar direct current distribution networks (DCDNs). However, the effectiveness of existing OPF models applied to bipolar DCDNs exhibits sensitivity to the problem type, underlying assumptions, and choice of objective functions. Hence, this paper proposes a dynamic decoupling-based convex-concave programming (CCP) framework to formulate an OPF model, aiming for a more rational impact across diverse applications in asymmetric operational bipolar DCDNs. More specifically, the coupled power between poles and ports of bipolar DCDNs is analyzed in detail, leading to the derivation of decoupled pole-to-ground equivalent circuits without relying on any preliminary assumption. Subsequently, the OPF problem of the equivalent circuits is formulated via CCP, involving the introduction of a cutting plane through difference-of-convex inequalities to limit the feasible region of the traditional OPF based on second-order cone programming, thereby diminishing dependence on exact relaxation conditions. Finally, a solution method is proposed to dynamically correct both the decoupled equivalent circuits and the cutting plane. The numerical results indicate that this method effectively addresses power optimization problems with a non-strictly monotonic objective function. Furthermore, it exhibits scalability, showcasing its applicability to large-scale radial bipolar DCDNs.

[ES] Este TFG tiene por objeto determinar las características necesarias para el diseño y la ejecución de una instalación fotovoltaica de autoconsumo, con una potencia que se concretará en el desarrollo del TFG, en el pabellón público de Benidorm Guillermo Amor . El objetivo principal es proporcionar energía limpia al polideportivo así como a los colegios colindantes, y, por tanto, reducir las emisiones de CO2 a la vez de disminuir su impacto ambiental. [EN] This DFD aims to determine the required characteristics for the design and implementation of a self-consumption photovoltaic installation, with a power that will be specified during the development of the work, in the public pavilion of Benidorm "Guillermo Amor". The main objective is to provide clean energy to the sports centre as well as to the surrounding schools, and therefore, reduce CO2 emissions while decreasing its environmental impact.