Hasil untuk "Electricity"

Juan C. Lopez-Mercado, Daniela Mahecha-Rivas, Juan P. Correa-Aguirre et al.

Energy access fundamentally drives community development. Powering essential services and infrastructure, reliable electricity facilitates social, economic, health, and educational progress. This study investigates the fabrication and characterization of epoxy (EP) and vinyl ester (VE)-natural fibers biocomposites for use in sustainable energy systems. The novelty of this research is based on an integrated approach that combines the characterization of biocomposites from fique and coir fibers with their application in the production of a functional vertical axis hydrokinetic turbine (VAHT) prototype. Characterization included tensile tests complemented by Digital Image Correlation (DIC) and Izod impact testing. The thermal properties were studied using Differential Scanning Calorimetry (DSC) and Thermogravimetric Analysis (TGA), and Scanning Electron Microscopy (SEM) was utilized to examine the adhesion and dispersion of fibers within the matrix. Viscoelastic properties were assessed using Dynamic Mechanical Analysis (DMA). Non-woven composites displayed a substantial stiffening effect, with improvements in tensile modulus reaching up to 33 % over neat resin. Non-woven fique fiber biocomposites showed the highest impact energy absorption (4.5 J), whereas EP-woven fique fiber specimens demonstrated superior tensile strength (35 MPa). Thermal degradation onset for VE-NWFF was observed at 397 ° Celsius. The results of the ANOVA test showed that fiber and fabric type have statistically significant impacts on mechanical performance (p ≤ 0.05). Research findings indicate that developed biocomposites can meet the necessary performance standards for hydrokinetic turbines production, providing a sustainable and cost-efficient alternative for distributed power networks in isolated areas.

Omar Mar Cornelio, Barbara Bron Fonseca

This study addresses the challenge of uncertainty, variability, and indeterminacy in smart grid energy management by applying neutrosophic logic as a novel optimization and detection framework. A computational methodology was developed to integrate renewable energy generation, battery storage, and consumption under neutrosophic modeling, comparing its performance with classical, fuzzy, and machine learning approaches. The neutrosophic economic dispatch model enabled improved generation scheduling resilience, optimized battery degradation prediction, and optimized charging cycles. In parallel, a neutrosophic detection mechanism was designed to identify energy losses, anomalous consumption, and potential fraud in near real-time. The case study results demonstrate that the neutrosophic approach significantly reduced operating costs (USD 8,500 versus USD 15,000–20,000 for other models), maximized the economic benefit of actual detections (USD 940, the highest among the tested models), and yielded the most favorable net balance (−USD 7,560). These results indicate that neutrosophic models outperform traditional and fuzzy approaches in both cost efficiency and system reliability.

Ismail Zabeeullah Kolimi, Julie Marteau, Salima Bouvier et al.

This study presents a comprehensive multi-scale investigation of the microstructural and mechanical properties of a large Ti–6Al–4V block fabricated via Additive Friction Stir Deposition (AFSD). AFSD is a solid-state additive manufacturing process with growing industrial relevance. While AFSD has been widely studied for small deposited blocks, its scalability and ability to maintain uniform properties across large build volumes remain underexplored. To address this, a large (250 × 30 × 80 mm3) Ti–6Al–4V block was deposited and systematically characterized through optical microscopy, SEM, EBSD, XRD, EDS, and full-field measurement using Digital Image Correlation (DIC)-assisted tensile testing. Alternating bands were observed across the deposited block; however, no elemental segregation, microstructural, or mechanical differences were observed across layers. The build demonstrated a consistent lamellar α+β microstructure with minimal retained β-phase with no defects or porosity. An isotropic and weak texture was seen throughout the deposition. Mechanical testing revealed uniform hardness (346–358 HV0.5), yield strength (∼906 MPa), and elongation (∼13 %) across both longitudinal and transverse directions. Full-field measurements revealed deformation to be homogeneous. Fractographic analysis confirmed ductile failure with a complete absence of porosity. When compared to prior AFSD and fusion-based studies, this work establishes the largest reported defect-free AFSD Ti–6Al–4V build to date with homogenous microstructure and consistent mechanical properties, achieved without post-processing or heat treatment. These findings validate AFSD's scalability and process stability for manufacturing large-scale components with microstructure and properties on par or above those of wrought or fusion-based AM.

Joseph Aristotle de Leon, Raymond R. Tan, Robert Kerwin Billones

Energy security is essential to ensure that energy is always available, affordable, and socially acceptable. To realize these aspects, this paper presents a design and business model for installing and operating a local energy community DC microgrid that allows individual households to power electrical loads for their homes and the whole community. Interested households can purchase solar PV units at a discounted price through a discount by the hosting local government unit (LGU). A percentage of the energy harnessed will be transferred through the microgrid to electrify public infrastructures such as streetlights, which covers the discount given. To optimize the setup so that both parties see the cost-saving potential of this new concept, a multi-objective linear programming (MOLP) model was developed to minimize the total cost by the participating households and the LGU. The optimization model was applied to a sample case study involving a community in the Philippines. Sensitivity analysis was also performed to identify the change in the objectives’ values when the case study’s inputs were changed. With the proper inputs to the model, the developed MOLP model successfully provided the optimal design and setup of the DC microgrid where both households and LGU have a lower lifetime electricity cost than relying on the main grid alone or the typical standalone solar energy setup.

Mohammad Farahani, Abouzar Samimi, Hossein Shateri

In this paper, the problem of participation of a Battery Energy Storage (BES) in the Day-Ahead Market (DAM) and Real-Time Market (RTM) in three cases including Joint Energy and Reactive Power Market (JERPM), Energy Market (EM) and Energy and Reserve Market (ERM) is modeled based on a hybrid Stochastic Robust Optimization (SRO) model and it tries to maximize the profit of the BES owner in the face of uncertainty pertaining to the market prices. In the proposed model, in the first step, the decision maker or BES owner predicts energy, reserve and reactive power prices in each market according to historical network information. In the second step, by determining the uncertainty interval of prices for DAM and RTM, robust optimization is implemented aiming at maximizing the profit of the BES owner using a model of forming a robust counterpart of the objective function and dual theory. In the next step, by defining some different scenarios for the robust budget, Stochastic Programming (SP) assigns a probability to each scenario. Then, the final profit of each market is calculated through probabilistic weighting, and finally the market with more profit is opted as considered participation market. The proposed formulation based on the Mixed Integer Nonlinear Programming (MINLP) model is implemented in the GAMS software environment and the results demonstrate the maximum profitability of BES in EM (21% more) and also show participation in providing ancillary services, such as reserve to provide security in incidents and reactive power to maintain stability and reduce cost and losses, despite the decrease in profit, leads to neutralizing the negative impact of uncertainties in the BES profit..

Eren Baharozu, Suat Ilhan, Gurkan Soykan

Distribution utilities responsible for supplying electricity face challenges in maintaining continuity of power supply and serving end consumers. Locating faults in the distribution network is a major challenge since faults can cause long-duration disruptions in power supply. Therefore, effective fault localization techniques, particularly for High Impedance Faults (HIFs), have become an area of focus. These faults are not detected by conventional protection equipment as they have currents with magnitudes similar to loads in the distribution network. Despite the considerable research efforts devoted to this issue, there is still no universal solution to locate such faults. Thus, this paper proposes a methodology that can identify the branch of HIFs in the distribution network and determine its location precisely. The proposed technique uses traveling wave method, Discrete Wavelet Transform (DWT), and Artificial Neural Network (ANN) as machine learning method. The proposed method has undergone numerous tests considering various inception angles, load variations, and different networks to prove its robustness and effectiveness. The results show that the proposed method is promising, with a high accuracy for determining faulty section and a low error ratio for fault distance calculations.

TU Lingbo

The semiconductor industry wastewater is complex due to it contains large amount of pollutants such as heavy metals, toxic cyanide, fluoride, nitrogen, and phosphorus, etc. Meanwhile, the poor biodegradability and low C/N makes it difficult to directly use biological methods for treatment. The sewage treatment plant in a certain high-tech industrial park adopts the treatment process of “grille+aeration sedimentation tank+high-efficiency sedimentation tank+advanced A2/O+MBR+disinfection tank”. The changes of influent and effluent water quality during the actual operation for 5 months were explored. The results showed that the treatment process had a good removal effect on pollutants. During operation, pollutants such as suspended solids, COD, NH4+-N, TN, TP, and fluoride in effluent were maintained below 4, 26, 1, 8, 0.1, and 1.5 mg/L, respectively, which always met the first level class A standards of Discharge Standard of Pollutants for Municipal Wastewater Treatment Plant (GB 18918-2002). In addition, the electricity cost of water treatment was about 0.536 yuan/m3, the chemicals cost was about 0.220 yuan/m3, and the direct operating cost was about 0.756 yuan/m3.

Jiacheng Huang, Xiaowen Zhang, Xuchu Jiang

Ensuring an adequate electric power supply while minimizing redundant generation is the main objective of power load forecasting, as this is essential for the power system to operate efficiently. Therefore, accurate power load forecasting is of great significance to save social resources and promote economic development. In the current study, a hybrid CEEMDAN-TCN-ESN forecasting model based on complete ensemble empirical mode decomposition with adaptive noise (CEEMDAN) and higher-frequency and lower-frequency component reconstruction is proposed for short-term load forecasting research. In this paper, we select the historical national electricity load data of Panama as the research subject and make hourly forecasts of its electricity load data. The results show that the RMSE and MAE predicted by the CEEMDAN-TCN-ESN model on this dataset are 15.081 and 10.944, respectively, and R2 is 0.994. Compared to the second-best model (CEEMDAN-TCN), the RMSE is reduced by 9.52%, and the MAE is reduced by 17.39%. The hybrid model proposed in this paper effectively extracts the complex features of short-term power load data and successfully merges subseries according to certain similar features. It learns the complex and varying features of higher-frequency series and the obvious regularity of the lower-frequency-trend series well, which could be applicable to real-world short-term power load forecasting work.

D. Sezer, D. Dai, T. F. Prisner

<p>In spite of its name, the solid effect of dynamic nuclear polarization (DNP) is also operative in viscous liquids, where the dipolar interaction between the polarized nuclear spins and the polarizing electrons is not completely averaged out by molecular diffusion on the timescale of the electronic spin–spin relaxation time. Under such slow-motional conditions, it is likely that the tumbling of the polarizing agent is similarly too slow to efficiently average the anisotropies of its magnetic tensors on the timescale of the electronic <span class="inline-formula"><i>T</i>₂</span>. Here we extend our previous analysis of the solid effect in liquids to account for the effect of <span class="inline-formula"><i>g</i></span>-tensor anisotropy at high magnetic fields. Building directly on the mathematical treatment of slow tumbling in electron spin resonance <span class="cit" id="xref_paren.1">(<a href="#bib1.bibx14">Freed et al.</a>, <a href="#bib1.bibx14">1971</a>)</span>, we calculate solid-effect DNP enhancements in the presence of both translational diffusion of the liquid molecules and rotational diffusion of the polarizing agent. To illustrate the formalism, we analyze high-field (9.4 T) DNP enhancement profiles from nitroxide-labeled lipids in fluid lipid bilayers. By properly accounting for power broadening and motional broadening, we successfully decompose the measured DNP enhancements into their separate contributions from the solid and Overhauser effects.</p>

Mu Yunfei , Wu Zhijun , Guo Haochen et al.

Currently, the isolated development of energy in the coal mining areas and the energy supply mode based on coal power generation and grid power supply can no longer satisfy the requirements for implementing clean coal-mining and building a new energy development pattern that is green, low-carbon, and recyclable. Therefore, it is necessary to build integrated energy microgrids in the coal mining areas to enhance the comprehensive utilization of energy and control carbon emissions in these areas. This study explores the demand for and natural advantages of integrated energy microgrids application in the coal mining areas, proposes an integrated energy microgrid framework, and analyzes the development elements of the framework: new energy generation, energy storage, associated energy utilization, multi-energy coupling, and optimal scheduling of energy. A material‒energy‒carbon hub model is established in the coal mining areas, realizing low-carbon operation optimization based on carbon ‒ energy synergy of integrated energy microgrids in typical coal mining areas. The results indicate that the application of integrated energy microgrids in coal mining areas can fully exploit and efficiently integrate the advantages of resources such as wind, solar energy, gas, air heat, and gushing water heat, and energy storage devices can further improve the match degree between energy supply and load demand, thereby reducing the amount of power purchased from the power grid and the carbon emissions from electricity consumption in the coal mining areas. The low-carbon operation optimization process takes into account the carbon‒energy coupling of various types of equipment and supports the formulation of low-carbon and economical operation strategies. This study is expected to provide new concepts and technical support for the high-quality economic and social development of coal mining areas.

M. M. Balashov

Over the past decade, the global energy sector has undergone major fundamental and structural changes as part of the global energy transition. The energy industry of the Russian Federation, as a key player in the global energy market and the world economy as a whole, is undergoing similar changes. In this case, in terms of ensuring high competitiveness and long-term energy security of the state, it is crucial to set priorities and build models of sustainable development for each of the industries related to the energy sector. Indeed, the process of replacing carbon-intensive energy sources with a systematic increase in the share of new, renewable energy sources (RES) should be gradual and consistent to avoid imbalances in energy systems and maintain equity for all stakeholders. In this context, the search for advanced, low-carbon energy sources is a priority for the vast majority of countries around the world. In addition, the development of renewable energy is one of the goals of Russia՚s energy strategy until 2035. At the same time, despite the obvious advantages of the Russian power industry such as the absence of dependence on budget funds, the overwhelming majority of private investment in the industry, the availability of effective mechanisms for attracting investment and the basic principle of balancing the interests of all market participants, there are also negative consequences of this approach. The nationwide task of developing the energy system and increasing the availability of electricity on the territory of the Russian Federation in terms of financing is becoming an exclusive burden on electricity consumers themselves; even insignificant risks in their operation can turn into a threat not only to sustainable development, but also to their very existence. In this context, the analysis of key directions and proposals to minimise the economic impact of the global energy transition on large energy-intensive industrial consumers of electricity and capacity is of particular relevance.

Wenyu Zhang, Yu Shen, Xuanyuan Wang et al.

As the main body of resource aggregation, Virtual Power Plant (VPP) not only needs to participate in the external energy market but also needs to optimize the management of internal resources. Different from other energy storage, hydrogen energy storage systems can participate in the hydrogen market in addition to assuming the backup supplementary function of electric energy. For the Virtual Power Plant Operator (VPPO), it needs to optimize the scheduling of internal resources and formulate bidding strategies for the electric-hydrogen market based on external market information. In this study, a two-stage model is constructed considering the internal and external interaction mechanism. The first stage model optimizes the operation of renewable energy, flexible load, extraction storage, and hydrogen energy storage system based on the complementary characteristics of internal resources; the second stage model optimizes the bidding strategy to maximize the total revenue of the electricity energy market, auxiliary service market and hydrogen market. Finally, a typical scenario is constructed and the rationality and effectiveness of the strategy are verified. The results show that the hybrid VPP with hydrogen storage has better economic benefits, resource benefits and reliability.

Gugulethu Nogaya, Nnamdi I. Nwulu, Saheed Lekan Gbadamosi

South Africa is one of the most carbon-intensive economies in the world, but it is presently experiencing an energy crisis, as its utility company cannot meet the country’s energy demands. The use of renewable energy sources and retiring of coal-fired power stations are two important ways of alleviating this problem, as well as decarbonizing the grid. Repurposing retiring coal-fired power stations for renewable energy generation (RCP-RES) while maintaining energy sustainability and reliability has rarely been researched. This paper proposes macro- and microelements for repurposing retiring coal-fired power stations for renewable energy generation in Camden with the aim of improving power generation through a low-carbon system. In this model, concentrated solar power (CSP) and solar photovoltaics (SPV), in combination with storage technologies (STs), were employed for RCP-RES, owing to their excellent levels of availability in the retiring fleet regions. The simulation results show that the power densities of CSP and SPV are significantly lower compared with retiring a coal-fired power plant (CFPP). Both are only able to generate 8.4% and 3.84% rated capacity of the retired CFPP, respectively. From an economic perspective, the levelized cost of electricity (LCOE) analysis indicates that CSP is significantly cheaper than coal technology, and even cheaper when considering SPV with a storage system.

Rareș-Lucian Chiriac, Anghel Chiru, Răzvan Gabriel Boboc et al.

Research in the process of internal combustion engines shows that their efficiency can be increased through several technical and functional solutions. One of these is turbocharging. For certain engine operating modes, the available energy of the turbine can also be used to drive an electricity generator. The purpose of this paper is to highlight the possibilities and limitations of this solution. For this purpose, several investigations were carried out in the virtual environment with the AMESim program, as well as experimental research on a diesel engine for automobiles and on a stand for testing turbochargers (Turbo Test Pro produced by CIMAT). The article also includes a comparative study between the power and torque of the naturally aspirated internal combustion engine and equipped with a hybrid turbocharger. The results showed that the turbocharger has a very high operating potential and can be coupled with a generator without decreasing the efficiency of the turbocharger or the internal combustion engine. The main result was the generation of electrical power of 115 W at a turbocharger shaft speed of 140,000–160,000 rpm with an electric generator shaft speed of 14,000–16,000 rpm. There are many constructive solutions for electrical turbochargers with the generator positioned between the compressor and the turbine wheel. This paper is presenting a solution of a hybrid turbocharger with the generator positioned and coupled with the compressor wheel on the exterior side.

Valentinus Galih Vidia Putra, Irwan Irwan, Ichsan Purnama et al.

In this research, Carbon black particles were applied on the woven fabric by the knife coating technique and pretreatment using plasma corona discharge to build-up conductive cotton-polyester (CVC 50%) fabric electromagnetic shielding material. This paper describes the making of anti-radiation weaving fabric using plasma technology. The anti-radiation patch was developed by first modifying the textile fabric's surface using atmospheric pressure plasma technology using tip-cylinder electrode configuration. The plasma corona discharge was generated using high voltage electricity with asymmetrical electrodes (tip and cylinder). The treated weaving fabric using plasma was then coated with carbon black ink. This research indicates that an anti-radiation weaving fabric was successfully shielded electromagnetic radiation from an electronic device.

Li Jun, Chen Zhengxi, Chen Chen et al.

Currently, the world is confronted with a series of challenges including resource shortage, climate change, environment pollution and energy poverty, which are rooted in the humanity’s deep dependence on and large-scale consumption of fossil energy. To tackle with those challenges is an urgent task for realizing sustainable development. The Global Energy Interconnection (GEI) is a clean energy-dominant, electricity-centered, interconnected and shared modern energy system. It is an important platform for large-scale development, transmission and utilization of clean energy resources at a global level, promoting the global energy transition characterized by cleaning, decarbonization, electrification and networking. The GEI has provided a scientific, novel and systematic solution to implement Agenda 2030 as well as the Paris Agreement. Focusing on the scope of clean transition and sustainable development, this paper has implemented qualitative and quantitative methods based on historic data. The global power demand and supply has been forecasted. Based on global clean energy resources endowments and distribution, a global main clean energy bases layout and generation planning optimization has been proposed. Later in this paper, the global power flow under the GEI scenario and corresponding GEI backbone grid has been explored and proposed. Finally, based on a preliminary investment estimation, the comprehensive benefits of building the GEI have been analyzed.

Carlos Lopes, Diogo Martino, Nuno Bandeira et al.

<p style="text-align: justify;">A decision support system (DSS) is a computerized information system that combines models and data to solve unstructured or semi-structured problems, with intense user involvement. DSSs have high applicability in several business areas and enable users without technical knowledge in computing to manipulate the information needed for a more assertive decision-making process. This study presents a DSS to support the decision process of installing a photovoltaic solution that considers the contracted power, the monthly expenses in electricity, and the location of the installation. The return on investment is estimated considering the annual savings in electricity and the return on investment. The findings indicate the relevance of the application to support the user in choosing the best solution and reveal that geographical location is a determining factor in the potential energy savings. Furthermore, the payback period decreases by increasing users' monthly consumption and is also potentiated by the increase in contracted power.</p>

Yoosung Park, Sung-Mo Yeon, Kyu-Hyun Park

Objectives:A whole process greenhouse gas emission factor was developed considering the direct greenhouse gas emission from the decomposition of livestock manure provided by the IPCC guidelines and the energy consumption of manure management systems. Methods:Greenhouse gas generated by animal manure management is divided into direct greenhouse gas emission by decomposition of manure and greenhouse gas effect in the entire process due to energy use by operating manure management systems. By obtaining and summing them, the whole process greenhouse gas emission factor for the livestock manure treatment system was calculated. Results and Discussion:Among the pig manure management systems, the greenhouse gas emission factors for composting, purification and liquefaction were calculated as 128 kgCO2-eq./ton, 123 kgCO2-eq./ton, 119 kgCO2-eq./ton, respectively. It was analyzed that 20.7% to 24.1% of greenhouse gas emissions generated in the process of managing manure were due to electricity use. As a result of analyzing the change in the emission factor according to the change in GHG emissions of the national electric power according to the 8th Basic Plan for Electricity Supply and Demand, a change in emission of about 6% was confirmed. Based on the results of this study and analysis of direct GHG emissions from manure management in three major Western European countries, France, Germany, and the Netherlands, based on the manure management emission factor in 2017, GHG emissions of 48.9% to 70% compared to this study in all countries. Conclusions:In the greenhouse gas emission factor for the pig manure management system, the greenhouse gas emission from energy used in the manure management system operation represents a contribution of more than 20%, so improvement of energy efficiency of the manure management system in the future can contribute to the reduction of greenhouse gas emission. As the GHG emissions of the pig manure management system are expected to change substantially according to the change in the power grid composition ratio according to the 8th Basic Plan for Electricity Supply and Demand, it is necessary to study the application plan in preparation for the implementation of product environmental footprint certification for livestock products in the future. As a result of comparing direct GHG emissions by manure management with major Western European countries, the difference in emissions was found to be large, suggesting the need to develop a Tier 2 emission factor suitable for the situation in Korea.

Egidijus Kasiulis, Petras Punys, Algis Kvaraciejus et al.

Small hydropower (SHP) plays an important role in the Baltic States as a reliable and efficient source of electricity from renewable sources. This study presents the historical development, current status, and possible trends for the future development of SHP in the Baltic States with insights into the legal background and development policies for SHP in Estonia, Latvia and Lithuania. For the assessment of hydraulic structures in the Baltic States, the historical data was used supplemented with data from hydropower associations, the national departments of statistics, electricity transmission systems operators, etc. The currently recommended best practice for SHP development is the utilisation of existing sites with available infrastructure. These include old water mill sites and existing dam sites, which, in the Baltic States, number more than 1500. The majority of these sites have their power potential attributed to micro-hydro (<100 kW). In this study the potential of the hydropower capacity at historic, currently nonpowered dams is evaluated and the distribution of the micro-hydro sites within the EU network of protected areas under Natura 2000 and nationally designated areas is presented. The potential electricity generation from such historic sites in the Baltic States is more than 200 GWh/year.

Locmelis Kristaps, Bariss Uldis, Blumberga Dagnija

The European Union’s climate and energy policy for 2030 sets ambitious targets and will challenge current energy use patterns. At the same time, policy objectives are to maintain energy affordable for business and consumers, which means that energy and climate goals should be achieved in the most cost-effective way. There is a well-known energy efficiency gap between effectively implemented energy efficiency measures and potentially economically viable ones. The authors have made a statistical analysis of the energy costs intensity of manufacturing industries in Latvia compared to other Baltic Sea countries and have consented that the three most energy consuming manufacturing industries in Latvia show a higher share of energy costs in total production costs than in their peers over a long period of time, indicating the clearly visible possibilities for energy efficiency improvements. At the same time, Latvian energy policy provides subsidies for energy-intensive manufacturing consumers by reimbursing part of their actual electricity costs. The paper analyses the amounts of reimbursements and their breakdown by manufacturing industries, identifying the most important beneficiaries of subsidies. The authors argue that beneficiaries should direct these subsidies to further energy efficiency improvements.