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El aumento en las concentraciones de dióxido de carbono (CO2) en la atmósfera ha generado un creciente interés en encontrar soluciones efectivas para reducir las emisiones de este gas de efecto invernadero. La implementación de sistemas de captura de carbono en el sitio en industrias está surgiendo como una estrategia crucial para abordar el cambio climático, ya que aporta beneficios significativos al reducir las emisiones en la fuente. La integración de sistemas de captura de carbono con almacenamiento de energía representa un paso innovador hacia la maximización de la eficiencia y sostenibilidad de todo el sistema. El CO2 capturado se convierte en una materia prima valiosa para su uso en el novedoso sistema de almacenamiento de energía y almacenamiento geológico basado en CO2 (CEEGS). El sistema utiliza ciclos de CO2 transcríticos para el almacenamiento de energía, y el CO2 se almacena geológicamente como una forma de energía derivada de plantas renovables excedentes. Esta práctica no solo disminuye la dependencia de los combustibles fósiles, sino que también ofrece una solución escalable para gestionar la inherente intermitencia de las fuentes de energía renovable. Este estudio abordará simulaciones de captura de CO2 mediante el uso del método emergente de captura de ciclo de calcio en aplicaciones específicas. Además, se investigará la integración de estas tecnologías con sistemas CEEGS., The increase in carbon dioxide (CO2) concentrations in the atmosphere has led to a growing interest in finding effective solutions to reduce emissions of this greenhouse gas. Implementing on-site carbon capture systems in industries is emerging as a crucial strategy to address climate change, as it brings significant benefits by reducing emissions at source. The integration of carbon capture systems with energy storage represents an innovative step towards maximising the efficiency and sustainability of the whole system. The captured CO2 becomes a valuable feedstock for use in the novel CO2-based electrothermal energy and geological storage (CEEGS) system. The system uses transcritical CO2 cycles for energy storage, and the CO2 is geologically stored as a form of energy derived from surplus renewable plants. This practice not only decreases dependence on fossil fuels but also offers a scalable solution for managing the inherent intermittency of renewable energy sources. This study will address simulations of CO2 capture using the emerging calcium loop capture method in specific applications. Additionally, the integration of these technologies with CEEGS systems will be investigated.

This study introduces an innovative solution to address the challenges arising from the volatile natural gas market and the growing integration of renewable energy sources within the industrial sector. The research strives to confront this challenge by including renewable methanol (CH3OH) and converting it into methane (CH4), with an intermediate step involving synthesis gas (CO/H2) by using concentrating solar power. This approach provides a sustainable and adaptable solution to reduce dependence on natural gas. The process entails a methanol decomposition reaction at moderate temperatures (<350 °C). Subsequently, the synthesis gas is compressed to 40 bar, stored, and discharged through a methanation process that can be conducted at high temperatures (>500 °C). The resulting methane is used as fuel for gas turbines and can also serve as feedstock in the chemical industry. The simulations were conducted in ASPEN HYSYS and yielded overall system efficiencies exceeding 29% and roundtrip efficiencies of 44%. Through techno-economic optimisation of the reaction conditions, competitive levelized fuel costs (LCOF) of €172/MWh and future LCOE values of €145/MWh were achieved. These findings present an innovative strategy for integrating gas turbine cycles and additional conversion pathways for green methanol.

The security of the supply of clean energy resources and the production of renewable fuels for industry are some of the strategies to combat climate change. In this sense, the massive implementation of green fuels that is foreseen forces the industrial park to operate on hydrogen and/or ammonia, methanol and others, with a cost overrun for stakeholders. This work proposes an alternative through a methanol-to-methane conversion system from the intermediate step to synthesis gas. Methanol decomposition is a process that can be produced with solar energy (CSP) at moderate temperatures (<350 °C) and at low cost, whereas methanation is a well-known and industrially mature process that occurs at temperatures < 625 °C. The integration of both processes is employed as a method of solar storage, namely through high-pressure syngas and its discharge for power production in conventional cycles. Recuperative ORC configurations, Rankine steam, and a sCO2 Brayton cycle were integrated; all of them of techno-economic interest, offering round-trip efficiencies higher than 50 % and levelized costs (LCOE) lower than EUR 55/MWh, considering a high-energy methane stream at the outlet. This offers a system that proposes a solution for the massive deployment of methanol as a green hydrogen carrier molecule, where it is capable of cleanly and efficiently storing thermochemical energy and producing high-purity methane at the output, usable in other power cycles, or as an industrial feedstock.

Este trabajo tiene como objetivo principal analizar el estado del arte de las plantas de potencia para su aplicación en reactores de fusión nuclear modulares, utilizando el software de ingeniería EES para modelar y evaluar su funcionamiento en la producción de energía. Comienza contextualizando la relevancia de la energía en la sociedad actual y la prometedora perspectiva de la fusión nuclear como una fuente de energía sostenible. Para comprender esta fuente de energía, se profundiza en las reacciones de fusión nucleares y el plasma, así como en los métodos de confinamiento magnético e inercial utilizados para mantener el plasma en condiciones propicias para la fusión. Se explora el enfoque específico de las plantas modulares de fusión nuclear, comparándolo con las plantas de energía de fisión nuclear y destacando los tokamaks esféricos como una opción relevante. Se discuten las similitudes y diferencias con las plantas modulares de fisión nuclear, además de considerar los aspectos económicos relacionados con los costes de implementación y el precio proyectado de la electricidad generada. La producción de energía en estas plantas es analizada en profundidad, incluyendo la consideración de ciclos termodinámicos integrados como el ciclo Rankine y el ciclo Brayton. Se proponen y evalúan varios modelos para comprender la conversión de energía de manera efectiva, realizando un análisis paramétrico que proporciona información crucial sobre la eficiencia y el rendimiento en condiciones variables. Finalmente se ofrece una visión integral del estado actual del conocimiento y proporcionan sugerencias para investigaciones futuras, subrayando la importancia de continuar desarrollando tecnologías relacionadas con la fusión nuclear para abordar los desafíos energéticos y ambientales., The primary aim of this academic work is to conduct an in-depth analysis of the state-of-the-art power plants intended for use in modular nuclear fusion reactors, utilizing engineering software EES for modeling and assessing their functionality in energy production. The study begins by establishing the societal significance of energy in the present day and exploring the promising outlook of nuclear fusion as a sustainable energy source. To gain a comprehensive understanding of this energy source, the study delves into nuclear fusion reactions and plasma, as well as the magnetic and inertial confinement methods employed to sustain plasma under conditions conducive to fusion. It further investigates the specific focus on modular nuclear fusion plants, drawing parallels with nuclear fission power plants and emphasizing spherical tokamaks as a pertinent option. Notable similarities and differences with modular nuclear fission plants are deliberated upon, along with a comprehensive examination of the economic aspects linked to implementation costs and the projected pricing of electricity generated. Energy production within these plants is rigorously analyzed, encompassing the consideration of integrated thermodynamic cycles, such as the Rankine and Brayton cycles. Multiple models are proffered and meticulously evaluated to facilitate a thorough comprehension of energy conversion, with the execution of a parametric analysis that furnishes indispensable insights into efficiency and performance under fluctuating conditions. Ultimately, the academic work culminates with a concise summary of the state-of-the-art knowledge and recommendations for prospective research, underscoring the pivotal importance of ongoing advancements in fusion-related technologies to effectively address contemporary energy and environmental challenges.

Actualmente nos encontramos en una transición del sistema energético mundial, que busca sustituir las fuentes de producción convencionales (gas, petróleo, carbón) por una generación 100% renovable. Apoyado por la reducción de emisiones de gases de efecto invernadero con el objetivo de mitigar los efectos del cambio climático, el uso predominante de renovables se perfila como factor clave en términos de desarrollo de mercado, independencia energética y sostenibilidad. El recurso renovable tiene una naturaleza estocástica e intermitente, que puede afectar negativamente a la calidad de la energía y a la estabilidad de la red eléctrica. El almacenamiento de energía, que permita vencer el desfase tanto diario como estacional, que existe entre la disponibilidad del recurso renovable y la demanda energética, es el componente necesario para mejorar la flexibilidad del sistema energético basado en generación 100% renovable. El desarrollo de nuevos sistemas de almacenamiento de energía a gran escala de alta eficiencia, de bajo coste, que utilicen materiales baratos y con bajo impacto ambiental, es necesario para poder aprovechar el recurso renovable. Esta tesis aborda el estudio de diferentes tecnologías de almacenamiento de energía térmica a gran escala, con capacidad de impacto, a diferentes niveles de temperatura y desarrollo; con el objetivo de contribuir en el grado de avance de nuevas soluciones de almacenamiento de energía de alta eficiencia y con un bajo impacto ambiental, que puedan integrarse en grandes plantas de potencia, facilitando la integración de renovables; desde la fase de planteamiento de la idea preliminar, al desarrollo del concepto a nivel de modelos, y con soporte experimental. El estudio se centra en tres prometedoras tecnologías de almacenamiento de energía térmica según el nivel de temperatura. La contribución a la investigación se divide en tres capítulos, cada uno dedicado a cada nivel de temperatura. El sistema de almacenamiento de energía electr, Currently global energy system transition is in progress, with the aim of replacing conventional production sources (gas, oil, coal) with 100% renewable generation. Supported by the reduction of greenhouse gas emissions in order to mitigate the effects of climate change, the predominant use of renewables is emerging as a key factor in terms of market development, energy independence and sustainability. In recent years, the member countries of the United Nations Framework Convention on Climate Change agreed to keep the global average temperature increase below 2°C above pre-industrial levels, and to pursue efforts to limit the temperature increase to 1.5°C (Paris Agreement, 2015). The renewable resource has a stochastic and intermittent nature, which can negatively affect power quality and grid stability. Energy storage, which allows overcoming both the daily and seasonal lag, which exists between the availability of the renewable resource and the energy demand, is the necessary component to improve the flexibility of the energy system based on 100% renewable generation. The development of new large-scale energy storage systems with high efficiency, low cost, using low-cost materials and with low environmental impact is necessary to take advantage of the renewable resource. This thesis addresses the study of different large-scale thermal energy storage technologies, with impact capacity, at different levels of temperature and development; with the aim of contributing to the degree of advancement of new energy storage solutions with high efficiency and low environmental impact, which can be integrated into large power plants, facilitating the integration of renewables; from the preliminary idea phase, to the development of the concept at the model level, and with experimental support. The study focuses on three promising thermal energy storage technologies depending on the temperature level. The research contribution is divided into three chapters, each dedicated to e

La intermitencia del recurso renovable conduce cada vez más a la necesidad de implementar sistemas de almacenamiento de energía, que aseguren el suministro energético y evitar los denominados curtailments. En este trabajo se desarrolla un sistema de almacenamiento de energía termoquímico, integrado a un sistema de energía solar de concentración (CSP) para promover la reacción de descomposición del amoníaco, para su posterior almacenamiento a alta presión en forma de gas de síntesis. Cuando así lo requiera la demanda, se liberará el syngas en la fase de descarga, produciendo amoníaco y liberando calor que podrá ser aprovechado para distintos usos, como será ha discutido. El sistema propuesto en el punto nominal de operación alcanza un rendimiento térmico del 50% y un rendimiento de conversión de energía solar a química del 46%, ofreciendo 8 horas de almacenamiento. Los costes nivelados de almacenamiento alcanzan valores de 130 €/MWh, siendo competitivo respecto a otras tecnologías de almacenamiento de su misma tipología. La flexibilidad del sistema permite la integración de un bloque de potencia a media temperatura compuesto por un ciclo de Rankine o un ORC, así como para la producción de calor de distrito., The intermittency of the renewable resource increasingly leads to the need to implement energy storage systems to ensure the energy supply and avoid the so-called curtailments. In this work, a thermochemical energy storage system is developed, integrated to a concentrating solar power system (CSP) to promote the ammonia decomposition reaction, for its subsequent storage at high pressure in the form of synthesis gas. When required by demand, syngas will be released in the discharge phase, producing ammonia, and releasing heat that can be used in different ways, as discussed. The proposed system at nominal operating point achieves a thermal efficiency of 50% and a solar to chemical energy conversion efficiency of 46%, providing 8 hours of storage. The levelized storage costs reach values of 130 €/MWh, being competitive with other storage technologies of the same type. The flexibility of the system allows the integration of a medium temperature power block composed of a Rankine cycle or Organic Rankine cycle, as well as for district heat production.

Among the portfolio of energy systems for local power generation, Organic Rankine cycles (ORCs) for residential applications are an opportunity for local cogeneration based on synergies with existing thermal heating and storage systems. They can be highly competitive for isolated installations and the refurbishment of existing solar heating installations based on solar domestic hot water. This article evaluates the potential for hybrid solar ORC integration in residential buildings. The analyses focus on the annual yields of a domestic 1 kW ORC cycle to assess the advantages and disadvantages of the variation of demand and the availability of solar resources. The models are developed, integrating TRNSYS and EES to allow a detailed evolution characterisation. Performance and impact of CHP adaptation are considered based on demand, storage volume-collectors area ratio, and production strategies. The analysis is completed with a thermo-economic analysis under different ranges of thermodynamic parameters. Positive IRR results of 8.61% are obtained for the installation located in Seville, Spain, operating the ORC 15% of the year. It also reduces the overheating associated with the lack of heat demand and excess solar irradiation in the solar system for the warm months by 20%.

This work presents an extension of the touch-free flash sintering technique. In the proposed technique, chemical reaction and sintering occur in a single step, without the use of electrodes, in the presence of electric and magnetic fields.We show that a dense, single-phase strontium hexaferrite magnet can be produced from a mixture of commercial carbonate and oxide powders in a single step in a little more than a minute. This new technique implies significant reduction in energy and time consumption (primarily because of ultrafast processing) relative to conventional sintering.

Thermal energy storage systems are an emerging option for efficient energy conversion and storage, especially if they can concentrate solar energy. This work studies a flexibleCH₃OH-to-CH₄ conversion system from intermediate conversion to synthesis gas. The design is based on a combination of processes already tested experimentally and applied in industry. The concept we develop integrates the decomposition of CH₃OH and methanation processes, providing different pathways for energy use, such as natural gas, direct heat, and power supply, or storage in chemical bonds. This flexibility in adapting the operation of the system to different energy availability and energy needs makes the concept appealing for changeable application. Thermal efficiencies of 39% are possible for the CH₃OH decomposition phase and of 26% for the overall system for CH₄ production. Thus, from the high energy density of CH₃OH, levelized storage costs of €134.8/MWh can be obtained, which is lower than systems based on molten salts. These results should spur interest in further advances for the proposed flexible concept.

With the increasing volatility in natural gas markets and the need for residential heat, research for alternative fuels is necessary for several regions. This paper presents a high-duration thermochemical energy storage system (TCES) based on methanol, evaluating its integration with district heating networks, offering a renewable solar-based storage solution and low-temperature heat generation from the exothermic discharge reaction heat. The system eliminates greenhouse gas emissions by using concentrated solar thermal energy to decompose methanol into synthesis gas. Applying the optimised operational thermodynamic parameters, it is possible to satisfy the thermal demand of 892 households in Spain through 12 MW of concentrated solar energy supported by 10 hours of energy storage. Storage efficiencies exceeding 30% and chemical conversion efficiencies exceeding 65% have been demonstrated, resulting in a combined efficiency of 55% for the heating network and methanol TCES. The results show a levelized cost of storage (LCOS) highly competitive with other storage systems (<100 €/MWh), given the simplicity and flexibility of the proposed system.

Heating decarbonisation through electrification is a difficult challenge due to the considerable increase in peak power demand. This research proposes a novel modelling approach that utilises easily accessible national-level data to identify the required heat storage volume in buildings to decrease peak power demand and maximises carbon reductions associated with electrified heating technologies through smart demand-side response. The approach assesses the optimal shifting of heat pump operation to meet thermal heating demand according to different heat storage capacities in buildings, which are defined in relation to the time (in hours) in which the heating demand can be provided directly from the heat battery, without heat pump operation. Ten scenarios (S) are analysed: two baselines (S1–S2) and eight load shifting strategies (S3–S10) based on hourly and daily demand-side responses. Moreover, they are compared with a reference scenario (S0), with heating currently based on fossil fuels. The approach was demonstrated in two different regions, Spain and the United Kingdom. The optimal heat storage capacity was found on the order of 12 and 24 h of heating demand in both countries, reducing additional power capacity by 30–37% and 40–46%, respectively. However, the environmental benefits of heat storage alternatives were similar to the baseline scenario due to higher energy consumption and marginal power generation based on fossil fuels. It was also found that load shifting capability below 4 h presents limited benefits, reducing additional power capacity by 10% at the national scale. The results highlight the importance of integrated heat storage technologies with the electrification of heat in highly gas-dependent regions. They can mitigate the need for an additional fossil-based dispatchable generation to meet high peak demand. The modelling approach provides a high-level strategy with regional specificity that, due to common datasets, can be easily replicated globa

This work presents a tool for developing competencies in sustainability, focusing on evaluating the environmental impact and carbon footprint in schools. The tool is based on sustainability indicators and follows a methodology derived from the ClimAct and ECF4CLIM projects. It is conceived as a support for the users and the schools to identify and evaluate the relative impact of different actions and measures, to engage them in a sustainable pathway to low-carbon schools supporting their decision-making at the different levels of users. The areas are transport, waste, green procurement, green spaces, energy, water, and indoor air quality. The tool aims to support users and schools in identifying and evaluating the impact of various actions and measures, facilitating decision-making for a sustainable and low-carbon school environment. To quantify sustainability performance, Key Performance Indicators (KPIs) have been established for each area. The results from schools that tested the tool revealed low scores in green procurement (0.59/5) and water (2.03/5), while achieving higher scores in green spaces (3.46/5) and indoor air quality (3.92/5). These findings highlight the areas where improvement is needed and provide a basis for targeted interventions. Developed on the PowerApps platform, supported by Microsoft, the tool allows access to users of different ages and knowledge levels. It has been successfully tested in six schools in Andalusia, Spain, obtaining relevant results in the seven sustainable areas defined. Based on the results, this tool will be used within co-creation and co-implementation processes for more sustainable schools and competencies acquisition by the participants.

This work presents an extension of the touch-free flash sintering technique. In the proposed technique, chemical reaction and sintering occur in a single step, without the use of electrodes, in the presence of electric and magnetic fields. We show that a dense, single-phase strontium hexaferrite magnet can be produced from a mixture of commercial carbonate and oxide powders in a single step in a little more than a minute. This new technique implies significant reduction in energy and time consumption (primarily because of ultrafast processing) relative to conventional sintering.

Heating decarbonisation through electrification is a difficult challenge due to the considerable increase in peak power demand. This research proposes a novel modelling approach that utilises easily accessible national-level data to identify the required heat storage volume in buildings to decrease peak power demand and maximises carbon reductions associated with electrified heating technologies through smart demand-side response. The approach assesses the optimal shifting of heat pump operation to meet thermal heating demand according to different heat storage capacities in buildings, which are defined in relation to the time (in hours) in which the heating demand can be provided directly from the heat battery, without heat pump operation. Ten scenarios (S) are analysed: two baselines (S1–S2) and eight load shifting strategies (S3–S10) based on hourly and daily demand-side responses. Moreover, they are compared with a reference scenario (S0), with heating currently based on fossil fuels. The approach was demonstrated in two different regions, Spain and the United Kingdom. The optimal heat storage capacity was found on the order of 12 and 24 h of heating demand in both countries, reducing additional power capacity by 30–37% and 40–46%, respectively. However, the environmental benefits of heat storage alternatives were similar to the baseline scenario due to higher energy consumption and marginal power generation based on fossil fuels. It was also found that load shifting capability below 4 h presents limited benefits, reducing additional power capacity by 10% at the national scale. The results highlight the importance of integrated heat storage technologies with the electrification of heat in highly gas-dependent regions. They can mitigate the need for an additional fossil-based dispatchable generation to meet high peak demand. The modelling approach provides a high-level strategy with regional specificity that, due to common datasets, can be easily replicated globa