Xiomara González-Ramírez

Residential electricity tariff structures in emerging economies are often highly complex, dynamically combining regional climatic variables and multi-tiered price adjustments. In Mexico, despite a preferential scheme designed to mitigate seasonal expenditure fluctuations, baseline energy subsidies frequently fail to protect low-income households due to structural targeting inefficiencies based strictly on regional temperature thresholds rather than socioeconomic status. This study addresses this methodological and regulatory gap by developing the Energy-Economic Impact Index (EEII), a novel mathematical and heuristic framework that couples complex Increasing Block Tariffs (IBT) architecture with localized household income dynamics at the state level. The proposed methodology was comprehensively validated using synchronized biennial empirical datasets from all 32 Mexican states, combining Federal Electricity Commission (CFE) billing data and National Surveys of Household Income and Expenditures (ENIGH) spanning the 2018–2024 period. Quantitative results reveal a severe, non-linear escalation of the financial energy burden across the territory, demonstrating that rising residential electricity costs significantly outpaced domestic income growth trajectories. Notably, households situated within high-temperature geographic regimes (Tariffs 1D, 1E, and 1F) exhibited the most critical economic vulnerability, with the calculated energy cost impact absorbing up to 14.90% of the real monthly household income in 2024. Ultimately, the EEII framework proves to be a robust predictive and decision-support tool for energy policy planners aiming to optimize fiscal subsidy allocation, reduce energy poverty gaps, and mitigate socioeconomic risks in transition economies.

Approximately 60% of the world’s primary energy is dissipated as waste heat, representing a critical opportunity for energy recovery in sectors such as electro-mobility and fuel cells. Commercial thermoelectric generators (TEGs), predominantly based on bismuth telluride (Bi₂Te₃), face limitations due to mechanical rigidity, toxicity, and high production costs. This study proposes graphene oxide (GO) as an emerging alternative thanks to its oxygenated functional groups and layered structure as well as GO paper facilitates’ thermal and electrical transport. However, the effective integration of this nanomaterial into solid-state systems under real operating conditions remains a technical challenge. Therefore, this work presents the development, multiphysics modeling, and experimental validation of an innovative TEG cell using GO paper as an active layer. The results demonstrate that the proposed GO-ITC achieves an average of 2.75 times higher generated voltage with a lower thermal gradient as well as an improved equivalent figure of merit (ZT) compared to Bi₂Te₃-based TEGs. This work contributes to the evaluation of GO-doped materials for voltage generation under specific thermal gradients, providing a lightweight and flexible solution for waste heat harvesting in modern power systems.

En la generación de electricidad, las fuentes renovables de energía tienen un gran impacto en el medio ambiente y en la calidad de vida de las personas. El consumo de energía mediante los combustibles fósiles es una de las principales causas de los gases contaminantes emitidos hacia la atmósfera, por esta razón hoy en día se busca desarrollar e investigar todo tipo de fuentes renovables que nos ayuden a disminuir la contaminación. Actualmente, el hidrógeno verde es visto como una importante fuente de energía limpia, ya que resulta crucial en los esfuerzos mundiales de descarbonización dado que no libera emisiones de carbono. Para producir hidrógeno verde es necesario un procedimiento químico, y este se logra a través de un proceso de electrólisis que emplea la electricidad producida por fuentes renovables. De esta manera, se puede iniciar con la descomposición de las moléculas de agua (H2O), en óxidos (O2) e hidrógeno (H2). El Hidrógeno Verde es crucial para disminuir los gases de efecto invernadero, dado que se propone como un impulsor energético en la batalla contra el cambio climático. Además, se proyecta que el hidrógeno y los combustibles basados en hidrógeno alcancen el 10% de la demanda total de energía a escala global para el año 2050 (IEA, 2021). El objetivo principal de este proyecto, a través de diferentes fuentes de consulta, es examinar las distintas tecnologías renovables a escala global en las que se emplea el Hidrógeno Verde, además de conocer las variables en la producción de hidrógeno verde con el objetivo de producir energía eléctrica, a partir de experimentación básica

El potencial energético por mareas oceánicas o energía mareomotriz es aquella que se obtiene con el movimiento de las mareas. Dado que es una fuente renovable de energía, es una opción para aprovechar este recurso al máximo debido a la creciente demanda energética que se presenta en el mundo actual. Por tanto, este trabajo propone la consulta del potencial energético por mareas oceánicas en algunos puntos de México, considerando la zona costera del Océano Pacifico y el Atlántico. El objetivo es revisar los parámetros de cálculo y definir cuál de los puntos seleccionados presentan mayor potencial energético. Este recurso natural presenta un gran potencial energético que puede ser transformado en energía eléctrica y por ende obtener grandes beneficios a la sociedad.

Designing and manufacturing transformers often involves variations in heights and thicknesses of windings. However, such geometric asymmetry introduces a significant impact on the magnitude of stray transformer losses. This study examines the effects of asymmetric coils on the generation of stray losses within core clamps and transformer tank walls. A model has been introduced to ascertain the dispersion magnetic field’s value at a specific distance from the coil. The analysis extends to characterising the dispersion magnetic field reaching the tank walls by using electromagnetic simulation by a finite element method. It explores strategies to diminish stray losses, including the placement of magnetic shunts as protective shields for the tank walls. It delves into the efficacy of employing a transformer shell-type configuration to mitigate the magnetic dispersion field. The findings revealed that achieving greater symmetry in transformer coils can minimise stray losses. Specifically, the incorporation of magnetic shunts has the potential to reduce additional losses by 40%, while the adoption of a shell-type configuration alone can lead to a 14% reduction. This work provides valuable insights into optimising transformer designs, contributes a user-friendly tool for estimating additional tank losses, thereby enhancing the knowledge base for transformer manufacturers.

In order to search new alternatives for electric power generation, the study of the wave energy potential was considered in this work, it deals with the develop for academic and research purposes an executable tool capable of providing the wave energy potential in any point of interest in the coastal zone of Mexico. To develop this tool, the main parameters were used: the significant height of the wave and its period. These parameters were obtained from an easily accessible oceanographic from the National Oceanic and Atmospheric Administration (NOAA) over a period of 6 years. The large database was statistically processed to obtain a reference base and applying numerical techniques for curve fitting, it was possible to obtain a characteristic equation to emulate the wave movement, this emulating model allows estimating the wave energy potential as a function of time and most attached to reality. This work contributes in the academic part in the estimation of wave energy potential, their visualization and understanding, to be a tool in the design of microgrids with renewables.

Computer-aided tool called design tool for wireless power transfer (DWPT) was created with the aim of designing wireless power transfer (WPT) systems and analyzing its relevant parameters that affect the output power estimation. This tool is capable of predicting the output power by considering various factors, such as transmitter/receiver coils separation, coils dimensions and geometric shape, averaged value of the magnetic flux density induced on the receptor coil, induced voltage, and efficiency. DWPT uses the analytical equations obtained through a circuital model of the WPT and complemented with an analytical model for coupling coefficient between coils, which was obtained from finite element simulations' results. DWPT was created in MATLAB graphical interface. DWPT results were contrasted with numerical simulation by finite element to validate them. The average difference between them reached 8%. In addition to the acceptable precision of DWPT, it is possible to design WPT systems quickly and with less computational burden compared to finite element simulations. Thus, DWPT can be a very valuable tool for identifying the crucial parameters of WPT design. Besides, it provides an idea of the electrical energy that can be obtained before proceeding to the manufacturing stage.

The study of wave potential at coastal points requires involving many parameters and degrees of freedom of ocean wave motion. In this work, we focus to the two most relevant ones: the wave’s significant height and its periodicity. By means of a descriptive statistical analysis of oceanographic databases from two coastal nodes in Mexico, we present realistic estimations of wave potentials. This work allows advancing the knowledge for the estimation of ocean wave energy potential and can be useful for future design of distributed generation plants based on this renewable alternative.

In this paper, a Static Synchronous Compensator based on the direct Matrix Converter (MC-STATCOM) is proposed for reactive power compensation. The MC-STATCOM allows eliminating the energy storage device used in conventional STATCOM topologies, besides improving some of its operational characteristics. This device is controlled through a linear control strategy in order to ensure its stability and dynamic response. The MC-STATCOM performance is verified through several time domain simulations carried out in MATLAB /Simulink©. The results obtained validate the feasibility of the topology proposed.