Open Access
New design alternatives for a hybrid photovoltaic and doubly-fed induction wind plant to augment grid penetration of renewable energy
(IEEE, 2021) Goñi, Naiara; Sacristán Sillero, Javier; Berrueta Irigoyen, Alberto; Rodríguez Rabadan, José Luis; Ursúa Rubio, Alfredo; Sanchis Gúrpide, Pablo; Ingeniaritza Elektrikoa, Elektronikoaren eta Telekomunikazio Ingeniaritzaren; Institute of Smart Cities - ISC; Ingeniería Eléctrica, Electrónica y de Comunicación; Universidad Pública de Navarra / Nafarroako Unibertsitate Publikoa
Reducing carbon emissions is essential to stop climate change. The grid-share of renewable generation plants is increasing, being wind and photovoltaic plants the most common ones, whereas conventional plants are the only ones that provide the necessary services to maintain the grid stability and keep the generation-demand balance. However, with the aim of achieving carbon-neutral generation, conventional plants are being dismantled. This leads to the imminent need of providing these services with renewable plants. Due to this challenge, this proposal analyses a hybrid plant composed by wind and photovoltaic generation with two types of storage, lithium-ion batteries and a thermal storage system based on volcanic stones. In order to compare both strategies, a technoeconomic methodology is explained that allows to optimally size the plant, using the current prices of each technology. The most cost-competitive proposal turns to be the hybrid plant with thermal storage, composed by 623.9 MW installed power and 21.9 GWh of storage, which could replace a 100 MW, 24/7 conventional power plant, with an LCOHS (levelized cost of hybrid system) of 118.38 €/MWh, providing identical grid services and an equivalent inertia in a way committed with the environment. This is in turn a zero-carbon emissions solution perfectly matched to a second life plan for a conventional power plant.
Open Access
Role of student associations in the acquisition of competences in university engineering programs
(IEEE, 2023) Samanes Pascual, Javier; Parra Laita, Íñigo de la; Berrueta Irigoyen, Alberto; Rosado Galparsoro, Leyre; Soto Cabria, Adrián; Elizondo Martínez, David; Catalán Ros, Leyre; Sanchis Gúrpide, Pablo; Institute of Smart Cities - ISC
Students in the STEM field (Science, Technology, Engineering and Mathematics), do not only require deep technical knowledge, but a complete set of global skills related to management, teamwork, lifelong learning, personal development, communications skills or proactiveness, abilities often referred as soft-skills. Student-led organizations, and specifically, university student associations, are one of the best alternatives to promote the acquisition of soft-skills in STEM high education fields. These skills are competences already included in official university programs that can hardly be addressed or acquired from traditional university education. This article studies how student enrollment in student led organizations (SLOs), with an active participation on their organization and activities, allows engineering students to achieve a better development of these soft skills. As case study, a medium size university, with 9000-students and eleven SLOs, six of them focused on STEM related fields, is used in this paper. A survey is conducted among the university community to identify their degree of participation in SLOs, and to test whether participation in these initiatives increases students' self-perception of their soft skill acquisition during their university studies. This survey shows how students of engineering programs, with a high degree of involvement in SLOs, demonstrated greater confidence in their soft skills at the end of their university years.
Open Access
Extensive analysis of photovoltaic battery self-consumption: evaluation through an innovative district case-study
(AIP Publishing, 2019) Millet, Lluís; Berrueta Irigoyen, Alberto; Bruch, Maximilian; Reiners, N.; Vetter, M.; Institute of Smart Cities - ISC
Energy storage is one of the key elements within the actual stage of the energy transition, as it is probably one of the most important factors to allow high penetration of fluctuating renewable energies, such as wind or solar, in the existing power systems. Intensive research is being conducted to assess the economic aspects and technical performance of renewable energy-based systems supported by batteries by evaluating different services that batteries can provide to the electric grid or to the end-consumers. In Germany, where the majority of the currently installed 43 GW of PV capacity corresponds to small residential, commercial, or industrial facilities, an interesting market for batteries to enhance local self-consumption and autarky is already booming, with more than 80 000 storage system installations in 2017. In this context, this study presents a comprehensive analysis of the photovoltaic battery model by analyzing the technical and economic consequences that variations on the most relevant system parameters induce. The presented results are based on high resolution data obtained from a representative residential district with an autarky of above 95%. The employed battery model is based on the results obtained through an extensive test campaign and includes electrical and thermal sub-models. The analysis predicts that grid parity of residential PV battery systems can be reached in the upcoming years, with especially great potential of the retrofitting market for those PV installations which run out of the feed-in tariff policy.
Open Access
Building global competencies: a strategic approach to internationalization of engineering education
(Eindhoven University of Technology and Fontys University of Applied Sciences, 2023) Berrueta Irigoyen, Alberto; Samanes Pascual, Javier; Parra Laita, Íñigo de la; Goicoechea Fernández, Javier; Sanchis Gúrpide, Pablo; Ingeniería Eléctrica, Electrónica y de Comunicación; Institute of Smart Cities - ISC; Ingeniaritza Elektrikoa, Elektronikoaren eta Telekomunikazio Ingeniaritzaren; Universidad Pública de Navarra / Nafarroako Unibertsitate Publikoa
International mobility is an essential aspect of undergraduate education that enables students to acquire the necessary competences required by the European Higher Education Area (EHEA). However, small universities such as the Public University of Navarre (UPNA), which has approximately 9,000 bachelor's students, face challenges in providing effective mobility opportunities. The most significant hurdles include offering attractive mobility experiences to students and establishing mobility agreements with other universities. Nonetheless, the reduced size of UPNA provides some potential benefits, such as more personalized advice for students and better knowledge of the available destinations. This article discusses the internationalization strategy implemented by the Faculty of Industrial and ICT Engineering at UPNA, which has enabled over 25% of its students to participate in a mobility experience, resulting in a high satisfaction rate. This contribution provides valuable insights into how smaller universities can successfully offer international mobility programmes to their students.
Open Access
Impact of micro-cycles on the lifetime of lithium-ion batteries: an experimental study
(Elsevier, 2022) Soto Cabria, Adrián; Berrueta Irigoyen, Alberto; Mateos Inza, Miren; Sanchis Gúrpide, Pablo; Ursúa Rubio, Alfredo; Ingeniaritza Elektrikoa, Elektronikoaren eta Telekomunikazio Ingeniaritzaren; Institute of Smart Cities - ISC; Ingeniería Eléctrica, Electrónica y de Comunicación; Universidad Pública de Navarra / Nafarroako Unibertsitate Publikoa Gobierno de Navarra / Nafarroako Gobernua
Experimental aging studies are commonly conducted on lithium-ion batteries by full charge and discharge cycles. However, such profiles may differ from the actual operation of batteries in electric vehicles and stationary applications, where they are subjected to different partial charges and discharges. These partial cycles, which take place during a main charge or discharge process, are called micro-cycles if their depth of discharge is <2 %. A number of authors have pointed out the relevance of the time resolution to estimate the energy throughput of a battery due to these micro-cycles in applications such as renewable microgrids. However, to the best of our knowledge, there are no experimental studies in the literature that assess the impact of these micro-cycles on battery degradation. In this article, the impact of micro-cycles on the loss of performance of a lithium-ion battery is experimentally studied. The results show that micro-cycles have a negligible, or even positive effect on the aging of lithium-ion cells compared to the aging caused by full cycles. In fact, if charge throughput or equivalent full cycles are used to measure the use of a battery, then cells subjected to micro-cycles exhibit a 50 % extended lifetime compared to cells only subjected to full cycles. More precisely, cells including micro-cycles with depth of discharge of 0.5 % lasted for nearly 3000 equivalent full cycles, whereas cells aged under standard deep cycles lasted for no >1500. Nevertheless, if the number of deep cycles, disregarding micro-cycles, is the unit to measure battery use, then the degradation of cells with and without micro-cycles is similar. Based on this result, the number of cycles can be identified as a more accurate variable to measure the use of a cell, in comparison to charge throughput.
Open Access
Applied method to model the thermal runaway of lithium-ion batteries
(IEEE, 2021) Lalinde Sainz, Iñaki; Berrueta Irigoyen, Alberto; Sanchis Gúrpide, Pablo; Ursúa Rubio, Alfredo; Ingeniaritza Elektrikoa, Elektronikoaren eta Telekomunikazio Ingeniaritzaren; Institute of Smart Cities - ISC; Ingeniería Eléctrica, Electrónica y de Comunicación; Universidad Pública de Navarra / Nafarroako Unibertsitate Publikoa
The thermal runaway (TR) is one of the most dangerous phenomena related to lithium-ion batteries. For this reason, there are different proposals in the literature for its modelling. Most of these proposed models take into account the decomposition reactions between the internal components of the cell, and base the adjustment of the parameters on numerous abuse tests that lead to the appearance of TR. However, these tests are destructive, require specific equipment, present a high economic cost and are very time consuming. This paper proposes a modelling method which enables the development of TR models with the use of fewer resources. This method is based on chemical kinetics, which allow a simplification of the general modelling process published in the literature. At the same time it maintains good accuracy and makes it possible to define the TR behavior of any type of cell, regardless of its chemistry, shape or size. Furthermore, the proposed method allows the use of the experimental results most commonly presented in the specialized literature, which significantly reduces the need for destructive testing. The presented modelling method achieves a good compromise between accuracy and applicability in the validations shown in the paper.
Open Access
Onset of irreversible reactions in overcharging lithium-ion cells: an experimental and modeling approach
(IEEE, 2023) Irujo Izcue, Elisa; Berrueta Irigoyen, Alberto; Lalinde Sainz, Iñaki; Arza, Joseba; Sanchis Gúrpide, Pablo; Ursúa Rubio, Alfredo; Ingeniería Eléctrica, Electrónica y de Comunicación; Institute of Smart Cities - ISC; Ingeniaritza Elektrikoa, Elektronikoaren eta Telekomunikazio Ingeniaritzaren
Lithium-ion batteries are energy storage systems used in an increasing number of applications. Due to their flammable materials, their use entails risks of fire and explosion. The study of the abuse operation of these batteries before reaching the thermal runaway is a relevant research topic to prevent safety issues. There are various studies in the bibliography providing exhaustive thermal studies of the safe operating area, as well as concerning the thermal runaway. However, the onset irreversible reactions, that take place at a SOC around 110%, have not been properly analyzed. We present in this contribution an experimental study of this onset reaction measured in pouch Li-ion cells under various conditions of charge current and temperature. We also propose a lumped-parameter thermal model for the cell, which allows a detailed characterization of this exothermic reaction. The results achieved in this contributions can be a key tool to prevent overcharge accidents that may arise due to malfunctioning of the battery charger or battery management system.
Open Access
Energy storage systems based on lithium-ion batteries and supercapacitors: characterization, modelling and integration with renewable energies
(2017) Berrueta Irigoyen, Alberto; Ursúa Rubio, Alfredo; Sanchis Gúrpide, Pablo; Ingeniería Eléctrica y Electrónica; Ingeniaritza Elektrikoa eta Elektronikoa; Gobierno de Navarra / Nafarroako Gobernua
Los inconvenientes medioambientales, sociales y económicos que presentan los combustibles fósiles y nucleares están propiciando un uso cada vez mayor de fuentes de energía renovables. El fuerte desarrollo tecnológico de los sistemas de generación basados en estas fuentes de energía, especialmente de los sistemas eólicos y fotovoltaicos, ha abaratado enormemente sus costes de producción, resultando ya tecnologías competitivas en relación con las plantas convencionales. Actualmente, el principal obstáculo que limita su integración masiva en la red eléctrica es su gestionabilidad, dada la naturaleza intermitente del recurso renovable. Los sistemas de almacenamiento energético distribuidos, y en particular las baterías de litio y los supercondensadores, surgen como una de las mejores alternativas para mejorar la gestión de esta energía y facilitar la operación de una red el ectrica cada vez más basada en sistemas renovables. Esta tesis analiza en profundidad ambas tecnologías de almacenamiento, especialmente cuando funcionan en entornos de generación renovable. Las principales líneas de trabajo de la tesis son: Análisis del estado actual de las tecnologías; Estudio de la influencia de los fenómenos termodinámicos, electroquímicos y térmicos en el funcionamiento de estos sistemas de almacenamiento; Modelado electroquímico y térmico de ambas tecnologías de almacenamiento; Estimación del estado de carga y del envejecimiento en baterías de litio; Validación experimental de los modelos propuestos ante diferentes condiciones de funcionamiento; Desarrollo de metodologías para el diseño y funcionamiento óptimo de sistemas de almacenamiento basados en baterías de litio en entornos renovables y particularización para centrales fotovoltaicas.
Open Access
Experimental assessment of first- and second-life electric vehicle batteries: performance, capacity dispersion, and aging
(IEEE, 2021) Braco Sola, Elisa; San Martín Biurrun, Idoia; Berrueta Irigoyen, Alberto; Sanchis Gúrpide, Pablo; Ursúa Rubio, Alfredo; Ingeniaritza Elektrikoa, Elektronikoaren eta Telekomunikazio Ingeniaritzaren; Institute of Smart Cities - ISC; Ingeniería Eléctrica, Electrónica y de Comunicación; Universidad Pública de Navarra / Nafarroako Unibertsitate Publikoa; Gobierno de Navarra / Nafarroako Gobernua
Nowadays, the reuse of electric vehicle batteries is considered to be a feasible alternative to recycling, as it allows them to benefit from their remaining energy capacity and to enlarge their lifetime. Stationary applications, such as self-consumption or off-grid systems support, are examples of second-life (SL) uses for retired batteries. However, reused modules that compose these batteries have heterogeneous properties, which limit their performance. This article aims to assess the influence of degradation in modules from electric vehicles, covering three main aspects: performance, capacity dispersion, and extended SL behavior. First, a complete characterization of new and reused modules is carried out, considering three temperatures and three discharge rates. In the second stage, intra- and intermodule capacity dispersions are evaluated with new and reused samples. Finally, the behavior during SL is also analyzed, through an accelerated cycling test so that the evolution of capacity and dispersion are assessed. Experimental results show that the performance of reused modules is especially undermined at low temperatures and high current rates, as well as in advanced stages of aging. The intramodule dispersion is found to be similar in reused and new samples, while the intermodule differences are nearly four times greater in SL.
Open Access
Design and on-field validation of an embedded system for monitoring second-life electric vehicle lithium-ion batteries
(MDPI, 2022) Castillo Martínez, Diego Hilario; Rodríguez Rodríguez, Adolfo Josué; Soto Cabria, Adrián; Berrueta Irigoyen, Alberto; Vargas Requena, Dávid Tomás; Matías Maestro, Ignacio; Sanchis Gúrpide, Pablo; Ursúa Rubio, Alfredo; Rodríguez Rodríguez, Wenceslao Eduardo; Ingeniaritza Elektrikoa, Elektronikoaren eta Telekomunikazio Ingeniaritzaren; Institute of Smart Cities - ISC; Ingeniería Eléctrica, Electrónica y de Comunicación; Gobierno de Navarra / Nafarroako Gobernua
In the last few years, the growing demand for electric vehicles (EVs) in the transportation sector has contributed to the increased use of electric rechargeable batteries. At present, lithium-ion (Li-ion) batteries are the most commonly used in electric vehicles. Although once their storage capacity has dropped to below 80¿70% it is no longer possible to use these batteries in EVs, it is feasible to use them in second-life applications as stationary energy storage systems. The purpose of this study is to present an embedded system that allows a Nissan® LEAF Li-ion battery to communicate with an Ingecon® Sun Storage 1Play inverter, for control and monitoring purposes. The prototype was developed using an Arduino® microcontroller and a graphical user interface (GUI) on LabVIEW®. The experimental tests have allowed us to determine the feasibility of using Li-ion battery packs (BPs) coming from the automotive sector with an inverter with no need for a prior disassembly and rebuilding process. Furthermore, this research presents a programming and hardware methodology for the development of the embedded systems focused on second-life electric vehicle Li-ion batteries. One second-life battery pack coming from a Nissan® Leaf and aged under real driving conditions was integrated into a residential microgrid serving as an energy storage system (ESS).