Hasil untuk "Electricity"

P. Morse, H. Feshbach

Zhong Lin Wang, Jinhui Song

T. Ackermann

L. Taylor

Bistoon Hosseini

This article discusses forecasting the monthly electricity consumption time series of household subscribers using the similar pattern algorithm, which uses each subscriber’s unique consumption pattern. The primary goal of forecasting the monthly consumption of household subscribers is to issue monthly bills and cluster subscribers for consumption management planning. The study’s results demonstrate the efficiency of the proposed algorithm compared to traditional statistics and machine learning methods. Out of the 72,000 predictions made using the proposed algorithm, the mean absolute percentage error is 16.9%. This shows that the algorithm successfully forecasts the monthly consumption of subscribers. The similar pattern algorithm maximizes the use of information in the billing database and takes advantage of expert opinions, which play a crucial role in avoiding unusual forecasts. The household subscribers involved in this study are located in two climatic regions: temperate and tropical. As this study has shown a significant dependency of household electricity consumption on the two major climate types, the obtained results have the potential to be generalized to other climatic regions as well.

Victoria A Lang, Sara F Camilleri, Anastasia Montgomery et al.

Electric vehicle adoption strategies have the potential to reduce greenhouse gas and air pollutant emissions. However, the effectiveness of this transition may depend on which vehicles are electrified, and where. To assess the efficacy of different modes of transportation electrification, we apply a watts-to-wheel analysis framework that accounts for upstream emission increases from battery charging and downstream reductions in tailpipe emissions. Using the WRF-CMAQ chemical transport model at ∼1 km ^2 resolution, we compare the greenhouse gas, air quality, and public health impacts of electrifying 30% of light-duty vehicles (eLDVs) versus 30% of heavy-duty vehicles (eHDVs) across a U.S. Midwestern domain. Both electrification scenarios achieve net reductions in CO _2 emissions despite increased emissions from electricity generation units, with greater total reductions from eLDVs (∼7 Mt CO _2 /year, −4.5%) than eHDVs (∼1.6 Mt CO _2 /year, −1.1%). However, air quality benefits are greater in the eHDV scenario, where cumulative reductions in health-harming air pollutants such as nitrogen dioxide (NO _2 ) and elemental carbon (EC) exceed those in the eLDV scenario. Both scenarios show modest increases in daily 8 h average ozone (MDA8 O _3 ), with disbenefits largest in the eHDV scenario. Estimated health benefits of the eHDV scenario exceed those of the eLDV scenario, with 70 (50) more avoided premature deaths annually from reduced NO _2 (EC), offset by 50 additional deaths from MDA8 O _3 increases. In both scenarios, the largest health benefits occur in communities with higher proportions of Black and Hispanic residents. However, long-standing relative exposure disparities persist. On a per-vehicle basis, we find that electrifying one HDV yields nearly 5× more CO _2 reduction-based economic benefits and 23× more NO _2 reduction-based economic health benefits than a single eLDV. Our results demonstrate that multi-modal and multi-pollutant assessments are critical for informing more effective and equitable decarbonization and air pollutant remediation strategies.

Shuo Chen, Dongmei Yan, Cuiting Li et al.

Urban electricity power consumption (EPC) prediction plays a crucial role in urban management and sustainable development. Nighttime light (NTL) remote sensing imagery has demonstrated significant potential in estimating urban EPC due to its strong correlation with human activities and energy use. However, most existing models focus on annual-scale estimations, limiting their ability to capture month-scale EPC. To address this limitation, a novel monthly EPC prediction model that incorporates monthly average temperature, and the interaction between NTL data and temperature was proposed in this study. The proposed method was applied to cities within the Yangtze River Delta (YRD) urban agglomeration, and was validated using datasets constructed from NPP/VIIRS and SDGSAT-1 satellite imageries, respectively. For the NPP/VIIRS dataset, the proposed method achieved a Mean Absolute Relative Error (MARE) of 7.96% during the training phase (2017–2022) and of 10.38% during the prediction phase (2023), outperforming the comparative methods. Monthly EPC spatial distribution maps from VPP/VIIRS data were generated, which not only reflect the spatial patterns of EPC but also clearly illustrate the temporal evolution of EPC at the spatial level. Annual EPC estimates also showed superior accuracy compared to three comparative methods, achieving a MARE of 7.13%. For the SDGSAT-1 dataset, leave-one-out cross-validation confirmed the robustness of the model, and high-resolution (40 m) monthly EPC maps were generated, enabling the identification of power consumption zones and their spatial characteristics. The proposed method provides a timely and accurate means for capturing monthly EPC dynamics, effectively supporting the dynamic monitoring of urban EPC at the monthly scale in the YRD urban agglomeration.

Jean Nepomuscene Twahirwa, Celestin Ntivuguruzwa

This study investigates the effects of smart classrooms, comprehensive assessment management information systems, and remediation teaching techniques on teachers ‘and student’s conceptual understanding of physics. The participants included 67 students from Senior One, Senior Two, and Senior Three, purposively sampled from G.S Mushongi in Kirehe district, along with 40 physics teachers selected purposively from the same district. Data was collected using two instruments: the Physics Achievement Test and the Teacher Mixed Multiple-Choice Questionnaire. Both students and teachers underwent remediation and training, respectively. The study focuses on taught specific physics units for each grade level: Current Electricity and Qualitative Analysis of Linear Motion for Senior One; Magnetism and Demagnetization and Reflection of Light in Curved Mirrors for Senior Two; and Heat Transfer and Quantity of Heat, Renewable Energy and Non-Renewable Energy, and Introduction to Electromagnetic Induction for Senior Three. Descriptive and inferential statistics were computed to analyze the data, and the results were presented using tables and figures created using Microsoft Excel and Origin version 2019b software. For Senior-One, Senior-Three students, the post-test scores demonstrated a highly statistically significant improvement (p < .001), suggesting that the remediation positively influenced their performance. However, for Senior Two students, the data analysis did not show any statistically significant improvement in their performance after remediation (p > .05). The results indicated a significant difference after training (p < .001) for the teachers. This research highlights the importance of targeted remediation and smart classrooms in enhancing academic performance and teachers’ perceptions.

Mochammad Chaerul, Desmonda Fitri Milenia

ABSTRAK Energi, terutama dalam bentuk listrik merupakan salah satu kebutuhan esensial bagi manusia. Untuk memproduksi listrik dibutuhkan berbagai macam proses, termasuk melalui kombinasi pembangkitan tenaga gas dan uap. Dalam proses produksi, suatu Pembangkit Listik Tenaga Gas dan Uap (PLTGU) menghasilkan berbagai macam jenis limbah, diantaranya yang terkategori sebagai limbah Bahan Berbahaya dan Beracun (B3). Studi ini bertujuan untuk mengidentifikasi sumber timbulan dan mengevaluasi pengelolaan limbah B3 di suatu PLTGU di Kota Palembang, Sumatera Selatan. Metode yang digunakan berupa observasi detail dan analisis kepatuhan pengelolaan limbah B3 berdasarkan peraturan perundangan yang berlaku. Selama masa observasi, limbah B3 yang dihasilkan berupa minyak pelumas bekas atau oli bekas, sludge oil, kain majun bekas, kemasan bekas B3, filter bekas dari fasilitas pengendalian pencemaran udara, limbah terkontaminasi, sludge IPAL, dan limbah kimia hasil analisis laboratorium. Secara umum, PLTGU tersebut telah melakukan pengelolaan limbah B3 dengan memadai, terutama di tahapan pelabelan, pengemasan, dan penyimpanan. Pengangkutan dan pengolahan limbah B3 dikerjasamakan dengan pihak ketiga yang telah memiliki izin terkait. Pengelolaan limbah B3 di suatu industri menjadi penting agar tidak menimbulkan dampak negatif ke lingkungan dan kesehatan manusia. Kata kunci: evaluasi, limbah B3, pengelolaan, PLTGU ABSTRACT Energy especially in form of electricity is one of essential needs for human. To produce electricity, various processes are needed, including a combination of gas and steam power generation. In the production process, a Combined Cycle Gas-Fired Power Plant (CCGP) generates various type of wastes, including those categorized as Hazardous and Toxic Waste. The study aims to identify sources and to evaluate the hazardous waste management at a gas and steam power plant located in Palembang City, South Sumatra. The method used was detailed observation and analysis of hazardous and toxic waste management compliance based on applicable laws and regulations. During observation period, hazardous and toxic waste generated including used lubricating oil or used oil, sludge oil, used cloth, used hazardous and toxic packaging, used filters from air pollution control facilities, contaminated waste, sludge WWTP, and chemical waste resulting from laboratory analysis. In general, the gas and steam power plant has managed hazardous and toxic waste adequately, especially in the labeling, packaging and storage stages. Transporting and processing of hazardous and toxic waste was carried out in collaboration with third parties who have the relevant permits. Hazardous and toxic waste management in an industry is important so that it does not cause negative impacts to the environment and human health. Keywords: evaluation, CCGP, hazardous waste, management

Nana Sartika, Rini Sulistiawati

The Covid-19 pandemic caused a negative contraction in the economic structure. In West Kalimantan province, despite negative growth, the primary and secondary sectors surprisingly showed positive growth in the mining, electricity, and agriculture sectors. Based on this situation, we investigated the possibility of the structural transformation process during the pandemic. We applied Lewis's transformation theory to the analysis of primary, secondary, and tertiary sectors to examine the general trends. We used Static-Dynamic Location Quotient, Klassen typology, and Shift Share analysis, and discovered that the negative contraction in 2020 did not significantly affect each sector. However, the pattern indicates a failure in the transformation process between the tertiary and primary sectors, with the primary sector naturally proving to be the main sector in the economic structure. The critical point of our finding is that the failure of the structural transformation process was potentially caused and locked by the failure of labour shifting. To unlock the interchange of labour to modern industries, the government must address human resource issues, identify definite interchanged sectors, choose key sectors, and ensure each stage is passed thoroughlywith all necessary resources.

Cheng ZHONG, Di ZHAI, Yang LU et al.

To address the problem of reduced communication quality in narrow underground power pipe gallery, where wireless sensor network coverage is affected by irregular shapes, obstacles, and electromagnetic interference, a power monitoring coverage sensing model is constructed based on the minimum access rate constraint, and an improved gray wolf coverage optimization algorithm is proposed by combining neuron mapping and differential evolution. Firstly, a uniform initial population is generated by neuron chaos mapping. Then, the nonlinear convergence factor is used to balance the global and local search ability. And finally, a differential evolution algorithm is introduced to mutate the gray wolf individuals. A comparative simulation analysis is made of various coverage optimization methods, and the results show that the proposed algorithm has robust search capabilities and it can significantly improve the network coverage performance in the narrow underground power pipe galleries, while effectively satisfying the communication needs of the monitored nodes.

Adam Zając, Rafał Balina, Dariusz Kowalski

The energy security of each country is one of the main factors of its proper functioning. Currently, in the era of problems related to energy security resulting from, among other things, the war in Ukraine, this topic is particularly important. This article presents issues related to Poland’s energy security, understood as the financial and economic stability of enterprises operating in the energy industry. This stability is considered in two aspects: macroeconomic, where the focus is mainly on the aspect of state intervention in market processes; and microeconomic, where factors determining the financial security of energy enterprises were identified, including internal and external factors affecting the functioning of these entities. In order to achieve the assumed research goals, the analysis of the indicated problems was based on non-reactive research, consisting in the assessment of the available information. It included studies of normative acts, official statistical data, industry reports and analyses, as well as data obtained in the form of a public information request. Two basic research methods were used in the work—dogmatic–legal and comparative analyses. The identification of factors affecting the security of companies in the sector was carried out on the basis of data on the entire energy sector in Poland for the years 2015–2021 on a semi-annual basis. Vector-autoregressive models were used for the analysis. As a result of the analyses, it was established that market failures and public safety are the premises justifying the public financing of enterprises in the electricity generation, transmission, distribution and trade sectors. At the same time, the conducted research showed that the level of financial security of energy enterprises in Poland was affected by the ratio of the value of goods and materials sold to net sales revenue, as well as the level of EBIT (earnings before deducting interest and taxes) margin, and among external factors, the level of GDP (gross domestic product), CPI (consumer price index) and Crude Oil were important.

Sahat Sitompul, Winfrontstein Naibaho, Welmar Olfan Basten Barat

The main problem that is often found in the failure of microalgae production is poor water quality during the maintenance period. One of the causes of deteriorating water quality is the lack of oxygen which endangers microalgae which can inhibit cell growth so that it can reduce its productivity. On this basis, efforts are needed to refresh the water or aeration to help increase the dissolved oxygen (DO) level in the microalgae growth container using a paddle wheel. The development of an aerator blade design that has optimum efficiency is needed to reduce high electricity consumption and see more effective cell growth.

Viktor Burdovitsin, Ilya Bakeev, Kirill Karpov et al.

We describe our investigations of a plasma-cathode electron source designed for the deposition of oxide coatings by the electron-beam evaporation of dielectric materials. Tests carried out using oxygen as the working gas showed that the source is operable without a change in parameters for at least ten hours of continuous operation. The current–voltage characteristics of the hollow-cathode plasma source in oxygen displayed a monotonically increasing character, and the voltage dependence of the discharge current was exponential. At the same time, for argon, nitrogen, and helium, the discharge voltage remained unchanged over a current ranging from 0.1 A to 1 A. A possible reason for these differences is the formation of oxides on the electrode surfaces for operation in the oxygen, impeding the discharge operation and requiring higher voltages for the same current as the other gases. The dependencies of the electron beam current on the accelerating voltage were monotonically increasing curves for all the gases except for helium, for which the beam current remained unchanged with increasing voltage over a range from two to ten kilovolts.

Maria C. G. Hart, Sarah Eckhoff, Michael H. Breitner

Abstract With rising electricity demand through digitization and innovation, the urgency of climate change mitigation, and the recent geopolitical crisis, stakeholders in developing countries face the complex task to build reliable, affordable, and low-emission energy systems. Information inaccessibility, data unavailability, and scarce local expertise are major challenges for planning and transitioning to decentralized solutions. Motivated by the calls for more solution-oriented research regarding sustainability, we design, develop, and evaluate the web-based decision support system NESSI4D web+ that is tailored to the needs and capabilities of various stakeholders in developing countries. NESSI4D web+ is open access and considers location-specific circumstances to facilitate multi-energy planning. Its applicability is demonstrated with a case study of a representative rural village in southern Madagascar and evaluated through seven interviews with experts and stakeholders. We show that NESSI4D web+ can support the achievement of the United Nations Sustainable Development Goals and enable the very prerequisite of digitization: reliable electrification.

Lei CUI, Tong YANG, Ruliang ZHANG et al.

Insulated gate bipolar transistor (IGBT) is usually used in combination with power diode in power electric circuit because it has no reverse blocking ability. In order to reduce cost and parasitic inductance, the freewheeling diode and IGBT are integrated by process method, and a reverse blocking insulated gate bipolar transistor (RB-IGBT) is thus proposed. For reducing the terminal area of conventional reverse blocking IGBT, an improved composite terminal structure is proposed. The double doped field limiting ring is used to introduce a n-type low doping region near the p-type field limiting ring, which can reduce the lateral expansion rate of depletion region, increase device reliability, improve terminal efficiency and save terminal size.

Yeken A. Sanusi

Cities are unique centers of energy demand and greenhouse gas emissions. Although electricity provides multiple functions for urban residents, its supply in Nigerian urban centers is poor, and the attempts to understand this problem have been limited to national level. Therefore, this study aims to explore the dimensions of electricity supply problem; assess adaptations by households to inadequate electricity supply; examine the use of renewable energy-related facilities; and understand the perception of renewables by urban households, with five residential neighborhoods in Minna, the capital of Niger state, were covered. Data were collected using a questionnaire and the Facility Observatory Technique to document daily electricity supply to households. The collected data covered electricity connection, daily supply, adaptations to inadequate public supply, perception of renewable energy and willingness to shift to renewable electricity sources. Results indicate that households in Minna have an average of 5 hours of electricity daily, while only 25% have electricity at night (7.00pm and 10.00pm.). An index derived to demonstrate the nature of electricity supply to households indicates that the city has a darkness index of 0.81, indicating a situation of extreme inadequacy of electricity supply. The index has a 95% correlation with the proportion of households without electricity at night. The study also shows that 72% of the households use fossil fuel-driven plants while 84% are not familiar with the use of renewable resources for generating electricity. The paper holds that the willingness of the public to switch to renewable energy, the incremental nature of urban development, and the high costs incurred by households for non-sustainable alternative sources of electricity provide the foundation for a more concerted effort to develop renewable energy as a means of improving the availability of electricity in Nigerian urban centers.

Noor Shakir Mahmood, Ahmed Ali Ajmi, Shamsul Sarip et al.

The sustainability issues of energy management are among the open challenges that lack an integrative sustainable framework and need urgent solutions in the power plants. Extant literature has neither defined energy management sustainability adequately, nor developed any sustainable framework in the power plants. In light of this, the study responds to this research gap through achieving four objectives: (1) To create a coherent research taxonomy with a new scope, (2) To systematically analyze current challenges and future trends, (3) To identify the critical success factors (CSFs) of the energy management system (EMs) in the power plants, and (4) Develop a smart integrated framework to ensure the success and sustainability of EMs in power plants. The methodology is based on two approaches: the theoretical approach through comprehensively systematic literature review (SLR) and establishing a coherent research taxonomy to extract the CSFs. In contrast, the second approach is based on the judgment of technicians and energy experts working in power plants to develop a sustainable framework via a case study in the power plant. The SLR finding was employed with expert judgment to develop a smart model. The IBM-SPSS and PLS-SEM software were utilized to analyze data in the case study. The study was validated using three methods: first, content validity test through the SLR and expert arbitration. Secondly, the construct validity test via composite reliability (CR), Cronbach’s alpha (CA), and average variance extracted (AVE). Thirdly discriminant validity test through Fornell and Larcker Criterion. The normality assessment by Skewness and Kurtosis has also been checked. All the results proved the validity and reliability of the integrated framework for sustainable EMs in power plants. The results for CA and CR were above 0.7. and the results of AVE were more than 0.5. The data normality value of skewness and Kurtosis are +/-2. Thus, the case study results indicate that it was acceptable and confirmed the literature results. Also, it confirmed the success of the proposed sustainable framework. The results fulfilled the normative requirements for validity and reliability. This study succeeded in developing a smart and sustainable framework for the future directions of energy management in power plants, which is a novel outcome of this study.

Addisu Worku Bezabih

Abstract Background Energy is the main requirement for economic growth in any country and supports the modern economy. The energy sector is considered a vital element in developing countries because it meets energy needs. This article addresses the production of electricity using small hydroelectric power plants for rural applications. The main objective of this study was to assess the potential of the Ribb dam for small hydroelectric plants. The flow is very important for the production of hydroelectricity as the height of a proposed site is constant and the available flow is very variable. Result The flow duration curve is constant and it will vary from 20 to 50% from the nominal flow. Further, it will decrease when the percentage of the nominal flow increases. The best size of a small hydroelectric plant producing a maximum of electricity in the context of future projected flows in the study region. Further, the Ribb dam concluded that the average flow of 14.6331 m3/s, the smooth head of 70.37 m, and the average nominal power of 5.53 MW. Conclusion Small hydro system (SHP) is a promising alternative for the production of cheap and renewable energy in rural or developing areas.

Xin Ye, Huazhong Ren, Yanzhen Liang et al.

Thermal infrared (TIR) remote sensing technology is capable of acquiring large-scale land surface temperature (LST), which is a key factor in the energy exchange between land surface and atmosphere. The visible and infrared multispectral sensor (VIMS) equipped in the Chinese Gaofen-5 (GF-5) satellite can obtain four channels of TIR images with a 40 m spatial resolution. However, due to the change of working environment, the TIR sensor suffers a low-accurate radiometric calibration that needs improvement. This paper puts forward a new cross-calibration for GF-5/VIMS TIR images by linking the top of the atmosphere (TOA) radiance of the vertical angle MODIS observation with the GF-5/VIMS image to estimate the radiometric calibration coefficients, Gain and Offset. To verify the recalibration performance, a new nonlinear two-channel split-window (SW) algorithm and a light gradient boosting machine (LightGBM) method which is used to refine LST from the SW algorithm by minimizing the residuals, were developed for the recalibrated GF-5/VIMS TIR 3 and TIR 4 channels. The radiometric cross-calibration algorithm and the optimized SW algorithm were applied to real GF-5/VIMS TIR images. The validation results showed that the brightness temperature and LST were improved significantly, and the LST retrieval error was reduced greatly to 1.79 K after recalibration, indicating a large improvement of the LST retrieval for GF-5/VIMS TIR image using the proposed cross-calibration and SW algorithms.