Hasil untuk "Electricity"

Siddha Pimputkar, J. Speck, S. Denbaars et al.

J. Mao, Gang Chen, Z. Ren

Solid-state thermoelectric devices can directly convert electricity into cooling or enable heat pumping through the Peltier effect. The commercialization of thermoelectric cooling technology has been built on the Bi2Te3 alloys, which have had no rival for the past six decades around room temperature. With the discovery and development of more promising materials, it is possible to reshape thermoelectric cooling technology. Here we review the current status of, and future outlook for, thermoelectric cooling materials. Thermoelectric materials can generate electricity from waste heat but can also use electricity for cooling. This Perspective discusses coefficients of performance for these systems and the state-of-the-art for materials, and suggests strategies for the discovery of improved thermoelectric materials.

A. Züttel, A. Remhof, A. Borgschulte et al.

P. Olasolo, M. Juárez, M. Morales et al.

Joshua W. Busby, K. Baker, M. Bazilian et al.

Abstract The Texas freeze of February 2021 left more than 4.5 million customers (more than 10 million people) without electricity at its peak, some for several days. The freeze had cascading effects on other services reliant upon electricity including drinking water treatment and medical services. Economic losses from lost output and damage are estimated to be $130 billion in Texas alone. In the wake of the freeze, there has been major fallout among regulators and utilities as actors sought to apportion blame and utilities and generators began to settle up accounts. This piece offers a retrospective on what caused the blackouts and the knock-on effects on other services, the subsequent financial and political effects of the freeze, and the implications for Texas and the country going forward. Texas failed to sufficiently winterize its electricity and gas systems after 2011. Feedback between failures in the two systems made the situation worse. Overall, the state faced outages of 30 GW of electricity as demand reached unprecedented highs. The gap between production and demand forced the non-profit grid manager, the Electric Reliability Council of Texas (ERCOT), to cut off supply to millions of customers or face a systems collapse that by some accounts was minutes away. The 2021 freeze suggests a need to rethink the state’s regulatory approach to energy to avoid future such outcomes. Weatherization, demand response, and expanded interstate interconnections are potential solutions Texas should consider to avoid generation losses, reduce demand, and tap neighboring states’ capacity.

M. Shahidehpour, Zuyi Li, H. Yamin

Ibanga Effiong, Gabrial Anandarajah, Olivier Dessens

Mini-grids are increasingly deployed to expand rural electrification in developing countries, yet evidence on service-quality performance remains uneven. This systematic review synthesises empirical evidence from 22 peer-reviewed studies (2005–2025) on rural mini-grid performance across six energy-access indicators: electrification rate, availability of supply, hours of supply, affordability, reliability, and consistency (power quality). Using PRISMA-guided database searches in Scopus and Web of Science, 138 records were identified; following de-duplication and screening, 22 studies met the inclusion criteria. The evidence base is concentrated in Africa and Asia, and most studies adopt mixed-methods approaches combining household- and/or enterprise-level evidence with system or operational data. Across indicators, electrification outcomes are frequently positive but reported using heterogeneous metrics, often relying on connection counts rather than population-referenced rates (10/22 studies report electrification outcomes). Service availability and hours of supply vary widely, ranging from evening-only provision (~5 h/day) to near-continuous service (24 h/day), with several studies documenting demand–capacity mismatch and load shedding (9/22 quantify availability; 12/22 quantify hours). Affordability is most frequently reported (16/22 studies), spanning substantial household cost reductions in some settings to high tariffs that constrain uptake in remote contexts. Reliability is seldom quantified using extractable outage/downtime metrics (4/22 studies). No study reports standardised voltage/frequency power-quality measures; only proxy evidence relates to consistency, leaving power quality as a major evidence gap. Mini-grids can deliver meaningful improvements in rural electricity access, but the literature remains constrained by inconsistent indicator definitions, limited standardised reliability/power-quality measurement, and short monitoring horizons. Future research and regulation should prioritise harmonised service-quality metrics and longer-term, field-based performance evaluation.

Rajalakshmi K, R. Thirumalai Selvi

The building industry, which uses the most electricity, has a significant potential to contribute to energy consumption reduction. Commercial structures use more energy than other types of structures because of their productive and logistic features. In these types of structures, one of the main energy consumers is the HVAC system which comprises of heating, ventilation, and air conditioning, especially in arid conditions. Energy-efficient environment friendly HVAC system conception and execution can significantly lower the use of energy and support ecologically sound growth in business establishments. On the other hand, inadequate implementation of methods for reducing energy use may lead to a decline in the welfare of the environment. Therefore, in order to achieve energy efficiency and maintain the optimum degree of temperature regulation, a comprehensive energy conservation strategy is needed. To accomplish this goal, model predictive control strategy-based methodologies are used in this work. To estimate how much energy will be used in commercial buildings, four deep learning-based methods are utilised: radial basis function networks, multi-layer perceptrons, artificial neural networks, and back propagation neural networks. To further cut down on energy use, four distinct control mechanisms are used. The performance of the suggested solution is examined using performance measures like Mean Absolute Error and Mean Absolute Percentage Error.

Yungpil Yoo, Sang-Yup Lee, Seok-Ho Seo et al.

The feasibility of integrating a CCU (Carbon Capture and Utilization) plant into a green methanol production system was studied through detailed energy, exergy, and thermoeconomic analyses from process, economic, and environmental perspectives. In this system, wood chips are combusted with oxygen generated by an electrolyzer in a circulating fluidized bed boiler. Carbon dioxide, a primary component of flue gas, reacts with hydrogen produced by the electrolyzer to synthesize green methanol. The chemical formula for wood chip combustion was modeled and used in this study. Our thermodynamic modeling allows us to calculate the oxy-fuel combustion, carbon capture, and water electrolysis processes to obtain the amounts of carbon dioxide and hydrogen required to produce methanol. When the unit costs of wood chips and electricity are $0.15/kg and $0.120/kWh, respectively, and the system’s initial investment cost is $117.9 million, the production cost of green methanol is calculated to be $1.393/kg. Additionally, the unit costs of hydrogen and oxygen produced by the electrolyzer were $4.75/kg and $0.30/kg, respectively. However, if the unit cost of electricity is reduced by 50 %, the production cost of green methanol decreases to $0.90/kg, which is close to the market price. If the carbon dioxide produced is sold as carbon credits at $0.50/kg, the unit price of methanol drops to $0.89/kg. Using wind, solar, or nuclear energy to electrolyze water, the carbon emissions of this methanol plant are estimated to be around 0.11–0.45 kgCO2/kgMeOH.

Tianyi Ma, Jianxiong Qiu, Hu Wang et al.

Life cycle low-carbon capacity optimization is widely acknowledged as an effective way to reduce carbon emissions and achieve sustainable development. Addressing the balance between carbon emission reduction and investment costs in integrated energy systems (IES) optimization of capacity configuration and incomplete life cycle boundaries issues, this paper establishes a multi-objective optimization model for IES in a whole life cycle boundary. The optimization is solved using Non-dominated Sorting Genetic Algorithm II (NSGA-II) combined with the entropy weight method and the Technique for Order Preference by Similarity to Ideal Solution (TOPSIS). The results reveal marginal effects between investment costs and carbon emissions. Compared to the original scenario, the life cycle low-carbon optimized plan reduces 56.1 % of carbon emissions and 18.8 % of costs, with 2 % of the carbon emissions and 7.3 % of the cost reduction coming from downstream. The relative proximity degree of the life cycle low-carbon optimization plan is twice that of purchasing green electricity, increasing 8.8 % of carbon emissions while reducing 24.9 % of costs. This indicates that green electricity purchases can only be used as a complementary strategy for sustainable development and should not be overly relied upon. This study focuses on balancing life cycle economics and carbon emissions by designing energy equipment capacity configurations of IES to achieve sustainable development in manufacturing enterprise parks.

Yasser Abbas Hammady AL-Elanjawy, Mustafa Yilmaz

As a consequence of the limited availability of fossil fuels, green energy is gaining more and more popularity. Home and business electricity is currently limited to solar thermal energy. Essential receivers in current solar thermal power plants can endure high temperatures. This ensures funding for green thermal power generation. Regular solar thermal power plant testing is arduous and time-consuming. They need expensive installation and take up much space. Many free software and tools can model and simulate solar thermal-producing systems. Some techniques can evaluate and predict the plant’s performance, while others can investigate specific components. Nothing using research tools has ever reached the top. Simulated testing may precede power plant construction. This research requires basic visual help. A rudimentary plant model was developed when the computational calculations for thermal performance were obtained. Plus, it may estimate how much power the facility would produce. The program includes hydraulic heat transport fluids, ambient factors, a database, and user input parameters. Free hourly weather data from anywhere is available from the simulator. The simulator calculates the thermal power delivered by each component while running constituent simulators.

П.Я. Мамедов

Relevance. Geothermal energy offers a clean and sustainable alternative to fossil fuels for electricity and heat generation. This study explores the potential for utilizing geothermal energy alongside existing oil production in the Bibiheybat field, Azerbaijan. The aim of this work is to assess the geothermal energy potential of the Bibiheybat field and evaluate its feasibility for electricity generation. Methods. The study analyzes well flow rates, temperatures, and pressure distributions within the X stratum of the field. Temperature and pressure distribution models are developed using Surfer software. Geothermal energy potential is calculated based on well data and formula application. Binary cycle technology is proposed for electricity conversion. Results. The X stratum exhibits an anticlinal fold structure with varying well depths and temperatures (46-24°C). The geothermal energy potential of the field is estimated at 307,578.56 kWh, with 25,090.15 kWh carried by oil and 282,488.41 kWh by water. Utilizing a binary cycle power plant, approximately 107,652.49 kWh of electrical energy could be generated.

Chinyere Theresa Ogbuanya

Household electricity consumption rates are increasing globally. However, saving electricity can decrease energy use, avoid wastage, and save financial resources for households. Therefore, this study was conducted to determine how attitude influences electricity-saving behaviors among household users in Nsukka District, Enugu State, Nigeria. The study adopted a descriptive survey design. A research question with corresponding null hypotheses was formulated and tested at a 0.05 level of significance. Stratified random sampling was used to select 400 household users, consisting of 206 females and 194 males. A structured questionnaire was used to collect information from the respondents. The questionnaire was validated by three experts and tested for reliability using the Cronbach alpha method. It contained respondents' personal data (biodata and demographics) and 28 items on attitudinal factors. The data obtained were analyzed to determine mean responses, and t-tests were used to test the null hypotheses at a 0.05 level of significance. The study found that gender does not influence the attitude of household users towards electricity-saving behaviors. It is recommended that government and non-government bodies organize training programs for household users of electricity to improve their attitude and promote more electricity-saving behaviors.

Samaher Al-Janabi, Ghada S. Mohammed, Thekra Abbas

In recent years, there has been an increasing demand for Renewable Energy (RE), which refers to energy generated from natural sources such as solar and wind power. Consequently, numerous scientific studies have been conducted to explore various approaches for controlling this type of energy. This work aims to highlight the main challenges associated with the generation and return of RE by employing intelligent data analysis techniques, specifically deep learning. These challenges are examined from different perspectives, including pre-processing, the methodology and techniques used in deep learning, and the evaluation measures employed. Some of the research in this area is focused on predicting the highest amount of energy that can be generated at a particular time and location, while others aim to predict the largest amount of electrical energy that can be returned to the electricity grid to optimize the use of surplus RE resources and maximize their benefits. These efforts are crucial to ensure the effective and continuous operation of the electrical grid. However, despite the efficiency and high accuracy of these models, they are hindered by complex calculations that require considerable time to produce the desired outcomes. Additionally, numerous measures are employed to evaluate the models' performance, including assessing their completion rate, quality of performance, accuracy of results, efficiency, error rate, feasibility of investing in RE, and the largest amount of surplus energy that can be returned to the electricity generation network.  

Qiufen Sun, Dong Sun, Canqing Yu et al.

Summary: Background: The impact of solid fuel use on life expectancy (LE) in less-developed countries remains unclear. We aimed to evaluate the potential impact of household solid fuel use on LE in the rural and urban Chinese population, with the effect of smoking as a reference. Methods: We used data from China Kadoorie Biobank (CKB) of 484,915 participants aged 30–79 free of coronary heart disease, stroke, or cancer at baseline. Analyses were performed separately for solid fuel use for cooking, solid fuel use for heating, and smoking, with participants exposed to the other two sources excluded. Solid fuels refer to coal and wood, and clean fuels refer to electricity, gas, and central heating. We used a flexible parametric Royston-Parmar model to estimate hazard ratios of all-cause mortality and predict LE at age 30. Findings: Totally, 185,077, 95,228, and 230,995 participants were included in cooking-, heating-, and smoking-related analyses, respectively. During a median follow-up of approximately 12.1 years, 12,725, 7,531, and 18,878 deaths were recorded in the respective analysis. Compared with clean fuel users who reported cooking with ventilation, participants who used solid fuels with ventilation and without ventilation had a difference in LE (95% confidence interval [CI]) at age 30 of −1.72 (−2.88, −0.57) and −2.62 (−4.16, −1.05) years for men and −1.33 (−1.85, −0.81) and −1.35 (−2.02, −0.67) years for women, respectively. The difference in LE (95% CI) for heating was −2.23 (−3.51, −0.95) years for men and −1.28 (−2.08, −0.48) years for women. In rural men, the LE reduction (95% CI) related to solid fuel use for cooking (−2.55; −4.51, −0.58) or heating (−3.26; −6.09, 0.44) was more than that related to smoking (−1.71; −2.54, −0.89). Conversely, in urban men, the LE reduction (95% CI) related to smoking (−3.06; −3.56, −2.56) was more than that related to solid fuel use for cooking (−1.28; −2.61, 0.05) and heating (−1.90; −3.16, −0.65). Similar results were observed in women but with a smaller magnitude. Interpretation: In this Chinese population, the harm to LE from household use of solid fuels was greater than that from smoking in rural residents. Conversely, the negative impact of smoking was greater than solid fuel use in urban residents. Our findings highlight the complexity and diversity of the factors affecting LE in less-developed populations. Funding: National Natural Science Foundation of China, National Key R&D Program of China, Kadoorie Charitable Foundation, UK Wellcome Trust.

Liyang Xiao, Jialiang Zhang, Chenghao Wang et al.

China has taken a number of positive measures to meet the requirement of environmental protection. The switch to electricity especially in transport sector is considered as a promising way to reducing greenhouse gas (GHG) emissions and facilitating to meet China's carbon neutral target in 2060. Besides, because of the overall impact of the COVID-19 on the transport sector, the future measures imposed by the government on electric vehicles (EVs) remain in high uncertainty. Taking the characteristics of different vehicles, business models, uncertainty of government financial subsidies and environmental factors into consideration, a replacement optimization model for a taxi fleet is proposed in this study under the cap-and-trade system. We assume that the taxi company has four types of vehicles to purchase or lease and manage to maximum the pecuniary advantages and environmental benefits simultaneously. Experimental results analyze that EVs and battery-swap electric vehicles (BSVs) are highly competitive when government subsidies do not decline. During the early stage of the planning horizon, adjusting the fleet continuously and timely can help the company to realizing the maximum revenue.

G. Stigler, C. Friedland

Feng Cui, Chuanfeng Han, Pihui Liu et al.

China’s green credit has mostly been invested in new energy areas with positive environmental externalities in recent years, while coal power enterprises have been neglected. This paper constructs a tripartite evolutionary game model among government, coal power enterprises, and banks to clarify the key factors and mechanisms for coal power enterprises undergoing green transformation. The research results show that: Firstly, to realize the spontaneous green transformation of coal power enterprises, spontaneous profitability must be achieved before the removal of policy incentives, which is reflected in the continuous increase in electricity price, carbon emission trading price, and decrease in green transformation cost. Secondly, the green credit adjustment factor cannot determine whether a company chooses to undertake green transition, but it provides a valuable window of green transition for companies. When the relative benefits of green transformation projects are greater than the relative costs, coal power enterprises will undergo green transformation spontaneously. Thirdly, lower green credit interest rates are not better. An optimal green credit interest rate exists, that allows coal power enterprises to obtain the longest transition window in which to achieve spontaneous profitability for green transition projects.

Qiang Chen, Junshuai Li, Qiang Chen et al.

Abstract The aqueous phase hydrogen peroxide (H2O2aq) produced from the plasma–liquid interactions can directly or synergistically (with other substances) affect the liquid chemistry, and therefore it is important to unfold the H2O2aq formation mechanism. However, up to now, a consensus on the H2O2aq formation mechanism is not reached. This review aims to survey the recent advances on the understanding of the H2O2aq formation mechanism in the system of a direct current discharge plasma operated over a liquid electrode. Theoretical and experimental analyses indicate that the recombination of dissolved OH radicals (OHaq) is the dominant process for the H2O2aq formation, while the purported plasma‐induced photolysis of water and the dissolution of gaseous H2O2 are ruled out.

Piotr Gradziuk, Aleksandra Siudek, Anna M. Klepacka et al.

Heat pump technology offers a path towards reducing the use of fossil fuels to heat space, providing energy bill savings and reducing air pollution and GHG emissions. The choice of heating method is based on costs; hence, this study examines the gains from operating heat pump systems in public buildings as well as alternative systems using electricity, LPG, and heating oil. The study focuses on the Ruda-Huta municipality in Poland that, as is common in rural areas, lacks access to a district heating system or piped gas. The empirical analysis includes heat pump installations in eight municipal buildings. The study found that the use of ground source heat pumps proved competitive with existing heating systems in terms of payback time. Calculations for three heating energy source scenarios, i.e., electricity, LPG, and heating oil, used the Simple Pay Back Time (SPBT) and the Levelized Cost of Heat (LCOH) methods and the average prices of the three energy types for the period 2012–2021. The payback period calculations disregarded the EU subsidies for heating systems utilizing renewable energy sources (RES). The payback time for electric, LPG, and heating oil were, respectively, 6.7–7.8 years, 4.1–6.1 years, and 6.7–6.9 years. Much larger spreads favoring heat pumps were calculated using the LCOH, and the costs in the case of electric heating were nearly three times higher and doubled when using heating oil and LPG. The gains from investing in heat pump systems have been offset by the increase in electricity, LPH, and heating oil prices, which have been predicted to continue to increase in the foreseeable future supporting the use of heat pumps in rural areas lacking access to, for example, district heating systems. The switch to heat pumps reduced local air pollution by eliminating the burning of fossil fuels to heat space in public buildings.