Optimal generation scheduling for renewable microgrids using hydrogen storage systems

The topic of this thesis is the development of a tool for an optimal energy management strategy (EMS) of the generators and energy storage systems constituent microgrids, both grid-connected or isolated (stand-alone power system) powered by Renewable Energy Sources (RES). In particular, a novel control system is designed based on the resolution of the unit commitment problem. For each time step, the proposed control system compares the expected power produced by the renewable generators with the expected load demand and determines the scheduling of the different energy storage devices and generators for the next few hours, which minimizes the operating cost of the overall microgrid. To take into account for forecasting uncertainties, the generation of the different scenarios is carried out through a discretization of the probability distribution function of the forecasting errors for wind speed, solar radiation and load requests by a set of finite states. A set of various scenarios are therefore analyzed and compared by the control system to find the minimum operating costs. The proposed algorithm is firstly applied to a microgrid at LABH2FER (Sardegna Ricerche, Italy). Since the microgrid is under construction, the expected performance is evaluated through a simulation modeling, implemented in Matlab-Simulink. Furthermore, in order to highlight the benefits of including weather forecasts and operating costs in the EMS, a comparative analysis with a simpler EMS based on control states of storage devices is carried out. The results of the comparative study demonstrate that a reduction of almost 5-10% in the annual operating costs and energy losses is achieved thanks to the implementation of the proposed control system. Moreover, the proposed control strategy is implemented and tested to a microgrid present at the University of Seville. Experimental results demonstrate the feasibility and the actual functionality of the control system. Additional benefits are also observed, such as the reduction in power exchanged with the upstream grid thanks to a better management of the storage systems

Advanced vehicle systems assessment. Volume 2: Subsystems assessment

Volume 2 (Subsystems Assessment) is part of a five-volume report entitled Advanced Vehicle Systems Assessment. Volume 2 presents the projected performance capabilities and cost characteristics of applicable subsystems, considering an additional decade of development. Subsystems of interest include energy storage and conversion devices as well as the necessary powertrain components and vehicle subsystems. Volume 2 also includes updated battery information based on the assessment of an independent battery review board (with the aid of subcontractor reports on advanced battery characteristics)

Modelling framework for the design of hydrogen-CCS networks to decarbonise heating and industrial clusters

This dissertation elucidates the value of H₂ and CO₂ infrastructure in decarbonising “difficult-to-abate” sectors of the economy. We analyse infrastructure for low-carbon fuels and energy vectors at different scales, and present a flexible formulation to integrate relevant technologies for their interconversion. We use a mixed integer linear programming (MILP) approach to formulate spatial systems optimisation problems, and identify solutions that can accelerate the transition to low-carbon systems. The modelling framework can incorporate spatial and temporal granularity, whilst also capturing the nuances of a site, country, or an industrial cluster. Through its application, we outline a transition pathway for the natural-gas based heating sector to H₂ in Great Britain, noting the key barriers to cost-effective deployment. The cost-optimal supply mix contains natural gas reforming with CCS, flexible electrolytic H₂ production, large volumes of salt cavern storage, and biomass gasification with CCS to offset any remaining methane and CO₂ emissions from the natural gas supply chain, and the production plants. Given the uncertainties involved, we note that a complete conversion of the gas grid in the UK to H₂ for heating buildings is unlikely to be viable. We find that a portfolio-based approach containing post-combustion CO₂ capture, fuel switching with H₂, and negative emissions is a cost-effective strategy to decarbonise industrial clusters in the UK. This achieves greater decarbonisation and avoids an overreliance on CO₂ emission offsets. The total costs of CO₂ avoidance can be reduced by using existing fuels such as refinery fuel gases for H₂ production. Natural gas plays an important role as fuel and feedstock for post-combustion and methane reforming, and is the primary determinant of the total costs of the system. This has implications for the security of supply, given that countries such as the UK import as much natural gas as they produce domestically. A cradle-to-gate lifecycle assessment of reforming, and electrolytic H₂ production using grid power and offshore wind power, shows that the lowest global warming potential is generated using a dedicated renewable-led supply. However, none of the production pathways are dominant across all key environmental performance indicators. This indicates the potential for “problem shifting” to occur by solely focussing on a given pathway for long-term supply development. We note that the environmental performance of H₂ improves with reductions in upstream methane emissions, and an increase in the capacity factor of renewable power generation assets.Open Acces

Analysis of the European Strategy for Hydrogen

This Final Degree Thesis focuses on analysing the aspirations of the European Union within the hydrogen sector. This aim is achieved through the examination of the European Parliament’s Hydrogen Strategy, allowing for a study of actions and projects in all hydrogen fields. The analysis is preceded by an exposition of the energy sector current situation and a description of the technologies associated with hydrogen, as well as an explanation of the most relevant plans and organisations that shape the rest of laws and initiatives (Paris Agreement, EU Green Deal…). It is followed by an overview of the international and Spanish hydrogen developments and the conclusions achieved. Any document that serves as a guide or strategy for any sector does inherently cover a wide range of topics so as to encompass the entirety of the sector, and this is the case for the strategy analysed. The European Parliament’s Hydrogen Strategy includes hydrogen demand, infrastructure, research and innovation, production, policies and more. This wide range of topics in the document studied implies a wide range of topics to delve into in this thesis, resulting in more than 150 information sources consulted to elaborate the thesis. The Hydrogen Strategy is crucial to understand the role of hydrogen in the EU and predict its future development. However, even though it was released about a year ago, it would already benefit from an update given that in a short period of time the energy context has changed (energy prices inflation, Russian conflict). In this situation of lack of security of supply and instability, the need for an energy carrier like hydrogen is more evident than ever. Moreover, hydrogen can be the key to the green transition and decarbonisation in the EU, which is why it is so important to keep on developing its technologies and to pursue this strategy.Este trabajo de fin de grado persigue analizar las ambiciones de la Unión Europea dentro del sector del hidrógeno. Este objetivo se alcanza a través del análisis de la Estrategia Europea para el Hidrógeno presentada por el Parlamento Europeo, que además permite que el estudio abarque todos los campos del sector del hidrógeno. El análisis es precedido por una contextualización del sector energético actual y por una descripción de las tecnologías del hidrógeno (para producción, transporte, almacenamiento, usos…), y también por una explicación de los planes y organizaciones más relevantes y que da forma al resto de leyes e iniciativas (Acuerdo de París, EU Green Deal…). Al análisis le sigue un resumen del desarrollo en materia de hidrógeno a nivel internacional y nacional (español), y finalmente las conclusiones obtenidas. Cualquier documento que cumpla el papel de guía o estrategia para un determinado sector abarca inherentemente un amplio abanico de temas para reflejar el sector al completo, y este es el caso de la estrategia que se analiza. La Estrategia Europea para el Hidrógeno incluye temas como la demanda de hidrógeno, infraestructura, investigación e innovación, producción, políticas, etc. Este amplio rango de temas del documento estudiado implica un amplio rango de temas que explorar en este trabajo de fin de grado, lo cual ha resultado en la consulta de más de 150 fuentes de información para la elaboración del trabajo. La Estrategia para el Hidrógeno es crucial para comprender el papel del hidrógeno en la UE y predecir su desarrollo en el futuro. Sin embargo, aunque fue publicada hace alrededor de un año, ya necesitaría una actualización para poder incluir los cambios del contexto energético que han tenido lugar en este corto periodo de tiempo (inflación en los precios de la energía, conflicto con Rusia…). Dada esta situación de falta de seguridad de suministro e inestabilidad, la necesidad de contar con un vector energético como el hidrógeno es más evidente que nunca. Además, el hidrógeno puede ser clave en la transición verde y descarbonización de la UE, por lo que es muy importante continuar desarrollando las tecnologías del hidrógeno y cumplir esta estrategia.Universidad de Sevilla. Grado en Ingeniería de la Energía (UMA/USE