1. Energy flexibility in aluminium smelting : a long-term feasibility study based on the prospects of electricity load and photovoltaic productionMarko Bizjak, Niko Uremović, Domen Mongus, Primož Sukič, Gorazd Štumberger, Haris Salihagić Hrenko, Dragan Mikša, Stanislav Kores, Niko Lukač, 2024, original scientific article Keywords: energy flexibility, aluminium smelting, renewable energy, virtual battery, solar production Published in DKUM: 17.12.2024; Views: 0; Downloads: 5 Full text (1,91 MB) |
2. The impact of financial support mechanisms and geopolitical factors on the profitability of investments in solar power plants in SloveniaIztok Gornjak, Filip Kokalj, Niko Samec, 2024, original scientific article Abstract: This article examines the impact of financial support mechanisms and geopolitical factors on the profitability of investments in solar power plants within Slovenia. The European Union’s energy policy prioritizes increases in renewable energy sources, aiming to reduce dependency on unstable and volatile fossil fuel markets. Solar power plants play a vital role in this transition. The energy policy framework also includes mechanisms and support systems to operate such facilities. This article analyzes electricity price trends over the past decade and addresses which support type—guaranteed purchase or operational support—has proven more profitable for investments in solar power plants up to 50 kW in Slovenia, considering economic and geopolitical influences on the electricity market. Although the global energy market has been affected by various significant events in recent years, it was found that the COVID-19 pandemic had minimal impact on the electricity market. In contrast, the onset of the conflict in Ukraine has contributed to rising electricity prices and has influenced the support dynamics essential for the development and sustainability of renewable energy systems. Analyses from the past decade indicate a higher return on investment in solar power plants when operational support mechanisms are chosen over guaranteed purchase support. Keywords: renewable energy sources, solar power plants, support system, investment profitability factors, electricity price Published in DKUM: 16.12.2024; Views: 0; Downloads: 5 Full text (4,96 MB) This document has many files! More... |
3. Conceptualizing a new circular economy feature - storing renewable electricity in batteries beyond EV end-of-life : the case of SloveniaMatevž Obrecht, Rhythm Singh, Timitej Zorman, 2022, original scientific article Abstract: Purpose: This paper aims to forecast the availability of used but operational electric vehicle (EV) batteries to integrate them into a circular economy concept of EVs’ end-of-life (EOL) phase. Since EVs currently on the roads will become obsolete after 2030, this study focuses on the 2030–2040 period and links future renewable electricity production with the potential for storing it into used EVs’ batteries. Even though battery capacity decreases by 80% or less, these batteries will remain operational and can still be seen as a valuable solution for storing peaks of renewable energy production beyond EV EOL.
Design/methodology/approach: Storing renewable electricity is gaining as much attention as increasing its production and share. However, storing it in new batteries can be expensive as well as material and energyintensive; therefore, existing capacities should be considered. The use of battery electric vehicles (BEVs) is among the most exciting concepts on how to achieve it. Since reduced battery capacity decreases car manufacturers’ interest in battery reuse and recycling is environmentally hazardous, these batteries should be integrated into the future electricity storage system. Extending the life cycle of batteries from EVs beyond the EV’s life cycle is identified as a potential solution for both BEVEOL and electricity storage.
Findings: Results revealed a rise of photovoltaic (PV) solar power plants and an increasing number of EVs EOL that will have to be considered. It was forecasted that 6.27–7.22% of electricity from PV systems in scenario A (if EV lifetime is predicted to be 20 years) and 18.82–21.68% of electricity from PV systems in scenario B (if EV lifetime is predicted to be 20 years) could be stored in batteries. Storing electricity in EV batteries beyond EV EOL would significantly decrease the need for raw materials, increase energy system and EV sustainability performance simultaneously and enable leaner and more efficient electricity production and distribution network.
Practical implications: Storing electricity in used batteries would significantly decrease the need for primary materials as well as optimizing lean and efficient electricity production network.
Originality/value: Energy storage is one of the priorities of energy companies but can be expensive as well as material and energy-intensive. The use of BEV is among the most interesting concepts on how to achieve it, but they are considered only when in the use phase as vehicle to grid (V2G) concept. Because reduced battery capacity decreases the interest of car manufacturers to reuse batteries and recycling is environmentally risky, these batteries should be used for storing, especially renewable electricity peaks. Extending the life cycle of batteries beyond the EV’s life cycle is identified as a potential solution for both BEV EOL and energy system sustainability, enabling more efficient energy management performance. The idea itself along with forecasting its potential is the main novelty of this paper. Keywords: circular economy, renewable electricity, storing renewable electricity, batteries, renewable energy Published in DKUM: 04.10.2024; Views: 0; Downloads: 5 Full text (696,15 KB) This document has many files! More... |
4. Quantifying power system frequency quality and extracting typical patterns within short time scales below one hourYounes Mohammadi, Boštjan Polajžer, Roberto Chouhy Leborgne, Davood Khodadad, 2024, original scientific article Keywords: quantifying power system frequency quality, statistical indices, pattern extracting, machine learning, short time scales, renewable energy sources Published in DKUM: 23.08.2024; Views: 50; Downloads: 5 Full text (12,67 MB) |
5. Energy storage potential of used electric vehicle batteries for supporting renewable energy generation in IndiaRajat Chauhan, Ram Santran, Matevž Obrecht, Rhythm Singh, 2024, original scientific article Abstract: As electric vehicle (EV) batteries degrade to 80 % of their full capacity, they become unsuitable for electric vehicle propulsion but remain viable for energy storage applications in solar and wind power plants. This study aims to estimate the energy storage potential of used-EV batteries for stationary applications in the Indian context. To estimate the renewable energy generation and used-EV capacity, the study adopted International Energy Agency (IEA) and International Council on Clean Transportation (ICCT) growth scenarios for renewable energy growth and electric vehicle growth, respectively. Battery degradation models for popular battery chemistries in electric vehicle mobility, namely Lithium Iron Phosphate, Lithium Manganese Oxide, and Nickel Manganese Cobalt, are employed to estimate reusable battery capacity. The first life for these battery chemistries, for mobility applications, ranges from 3.5 to 7 years. Results indicate an estimated storage potential of 1300–1870 GWh in used electric vehicle batteries in India by 2038. This is equivalent to 17 % – 39 % of average daily energy generation from solar and wind power plants in various scenarios by the year 2038. This research contributes to SDG-7 by facilitating clean energy accessibility through renewable energy storage and supports emission reduction efforts in transportation and energy sectors, thereby fostering sustainable cities (SDG-11). Keywords: used-EV batteries, battery degradation, renewable energy, energy storage, battery capacity, Li-ion batteries Published in DKUM: 09.08.2024; Views: 104; Downloads: 9 Full text (2,55 MB) This document has many files! More... |
6. 6th International Conference En-Re Energy & Responsibility : Book of Extended Abstracts2024 Abstract: In the context of escalating climate challenges, the EnRe conference is dedicated to exploring pathways to climate neutrality and the sustainable green transition. The conference is focused on the development and implementation of innovations supporting the transformation of energy systems, industrial systems, and living systems, all with the goal of creating a sustainable future with net-zero emissions. The conference brings together experts, researchers, policymakers, and business leaders to share their experiences, research, and visions. The aim of the conference is to foster collaboration and exchange of ideas, and to collectively develop comprehensive approaches and strategies for achieving climate neutrality. This conference is not just a knowledge exchange, but also a platform for encouraging concrete actions that will ensure a greenerand more sustainable future for our next generations to come. Keywords: alternative energy systems, dynamic tariffing, electrical machines and drives, energy conversions, financing energy projects, nuclear energy, conventional energy systems, climate changes - climate pan, mathematical methods in engineering, micro and nano energy, low-carbon technologies and strategies, renewable energy technologies heating and cooling systems, smart buildings, cities and networks, policies and strategies for renewable energy sources, energy efficiency and the climate Published in DKUM: 17.05.2024; Views: 332; Downloads: 40 Full text (10,40 MB) This document has many files! More... |
7. The Evaluation of Torrefaction Efficiency for Lignocellulosic Materials Combined with Mixed Solid WastesMaja Ivanovski, Darko Goričanec, Danijela Urbancl, 2023, original scientific article Abstract: The paper presents the results of research aimed at evaluating the possibility of using selected biomass wastes to produce solid biofuels. In this work, the thermochemical properties of two lignocellulosic biomasses, namely, miscantshus (Miscanthus × Giganteus) and hops (Humulus lupulus), and non-lignocellulosic biomass, namely, municipal solid waste, and their mixtures (micanthus + municipal solid waste and hops + municipal solid waste) were studied using the torrefaction process as the main method for investigation. The effects of various torrefaction temperatures (250, 300, and 350 °C) and times (30 and 60 min) were evaluated. Proximate and ultimate analyses were performed on the torrefied samples. The following can be stated: as the torrefaction temperature and time increased, mass and energy yields decreased while the higher heating values (HHVs) and fuel ratios (FRs) increased, together with carbon contents (C). In addition, energy on return investment (EROI) was studied; the maximum EROI of 28 was achieved for MSW biochar at 250 °C for 30 min. The results of studying greenhouse gas emissions (GHGs) showed a reduction of around 88% when using torrefied biochar as a substitute for coal. In sum, this study shows that torrefaction pre-treatment can improve the physicochemical properties of raw biomasses to a level comparable with coal, and could be helpful in better understanding the conversion of those biomasses into a valuable, solid biofuel. Keywords: torrefaction, waste biomass, renewable energy, fuel ratio, greenhouse gas emission, GHG Published in DKUM: 29.03.2024; Views: 222; Downloads: 24 Full text (3,69 MB) This document has many files! More... |
8. 5th International Conference EnEe - energy & responsibility : book of extended abstractsSebastijan Seme, Jurij Avsec, Klemen Sredenšek, 2022, preface, editorial, afterword Keywords: renewable energy and energy storage systems, classic energy systems, policies and strategies for res, alternative energy systems, energy conversions, energy transfer, electrical machine, thermal machines, mathematical methods in energy, engineering, environmental protection, micro and nano energetics, hydrogen technologies, low carbon technologies and strategies, nuclear energy, smart buildings, smart cities and smart grids Published in DKUM: 12.02.2024; Views: 328; Downloads: 11 Full text (14,78 MB) This document has many files! More... |
9. The use of differential evolution to determine maximum generation and load values in the distribution networkEva Tratnik, Janez Ribič, Matej Pintarič, Miran Rošer, Gorazd Štumberger, Miloš Beković, 2022, original scientific article Abstract: By integrating renewable energy sources into the existing distribution network, the characteristics and local stability of the network is highly impacted. The network, which was built with the goal of a directed energy flow from large conventional sources connected to the transmission network via the distribution network to consumers, can change the direction of the energy flow. The adoption of environmental commitments and directives encourages the integration of local dispersed energy sources, which can worsen voltage conditions in the distribution network. To avoid excessive local production, distribution network operators must limit the installation of new generati on units, as it is necessary to take into account the quality of power supply by monitoring its network parameters, such as the appropriate voltage profi le and the rati o between acti ve and reacti ve power. On the other hand, excessive loads due to the mass transiti on of household heati ng and transport towards electricity can also pose a problem for high-quality electricity supply due to the excessive voltage drop. The arti cle presents an algorithm for determining the maximum size of unit producti on and the maximum load at a node in the distributi on network. Also demonstrated is the use of variable tap transformer technology, which adjusts the tap of the transformer to provide an appropriate voltage profi le in the network. The enti re analysis was performed on a model of a real medium-voltage network, in which solar and hydropower plants are already included. The model was verifi ed by comparing its calculated values with actual measurements. The goal was to determine the size of the unit’s maximum producti on, as well as the size of the maximum load, by using the diff erenti al evoluti on algorithm, while keeping voltage profi les within the permissible limits. The results of the analysis are presented in the article. Keywords: distribution network, renewable energy sources, optimisation method, voltage profile Published in DKUM: 30.10.2023; Views: 425; Downloads: 17 Full text (1,63 MB) This document has many files! More... |
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