Search Results (246)

In the context of urban decarbonization, multi-energy microgrids (MEMGs) are gaining increasing relevance due to their ability to enhance synergies across multiple energy vectors. This study presents a block-based MILP framework developed to optimize the operations of a real MEMG, with a particular focus on accurately modeling the structure of electricity and natural gas bills. The objective is to assess the added economic value of integrating a battery energy storage system (BESS) under the assumption it is employed to provide implicit flexibility—namely, bill management, energy arbitrage, and peak shaving. Results show that under assumed market conditions, tariff schemes, and BESS costs, none of the analyzed BESS configurations achieve a positive net present value. However, a 2 MW/4 MWh BESS yields a 3.8% reduction in annual operating costs compared to the base case without storage, driven by increased self-consumption (+2.8%), reduced thermal energy waste (–6.4%), and a substantial decrease in power-based electricity charges (–77.9%). The performed sensitivity analyses indicate that even with a significantly higher day-ahead market price spread, the BESS is not sufficiently incentivized to perform pure energy arbitrage and that the effectiveness of a time-of-use power-based tariff depends not only on the level of price differentiation but also on the BESS size. Overall, this study provides insights into the role of BESS in MEMGs and highlights the need for electricity bill designs that better reward the provision of implicit flexibility by storage systems. Full article

Indonesia’s dependence on fossil fuel exports, particularly coal and crude oil, presents a dual challenge: sustaining economic growth while addressing rising CO₂ emissions. Despite significant attention to domestic energy consumption, the environmental implications of export activities remain underexplored. This study examines the dynamic relationship between energy exports, crude oil prices, and CO₂ emissions in Indonesia using a Vector Autoregressive (VAR) model with annual data from 2002 to 2022. The analysis incorporates Impulse Response Functions (IRFs) and Forecast Error Variance Decomposition (FEVD) to trace short- and long-term interactions among variables. Findings reveal that coal exports are strongly persistent and positively linked to past emission levels, while oil exports respond negatively to both coal and emission shocks—suggesting internal trade-offs. CO₂ emissions are primarily self-driven yet increasingly influenced by oil export fluctuations over time. Crude oil prices, in contrast, have limited impact on domestic emissions. This study contributes a novel export-based perspective to Indonesia’s emission profile and demonstrates the value of dynamic modeling in policy analysis. Results underscore the importance of integrated strategies that balance trade objectives with climate commitments, offering evidence-based insights for refining Indonesia’s nationally determined contributions (NDCs) and sustainable energy policies. Full article

Rising population, combined with declining home food production, in Arab nations has resulted in increased food imports that intensifies their dependence on international markets for vital food supplies. These nations face challenges in achieving food security because crude oil price volatility creates difficulties in managing the expenses of imported food products. This research calculates the income and price elasticities of imported food demand to understand consumer behavior changes in response to income and price variations, which helps to explain their impact on regional food security. To our knowledge, this research presents the first analysis of imported food consumption patterns across Arab countries according to their income brackets. This study employs the static Almost Ideal Demand System model to examine food import data spanning from 1961 to 2020. The majority of imported food categories demonstrate inelastic price and income demand, which means that their essential food consumption remains stable despite cost fluctuations. The need for imports makes Arab nations vulnerable to external price changes, which endangers their food security. This research demonstrates why governments must implement policies through subsidies and taxation to reduce price volatility risks while ensuring food stability, which will lead to sustained food security for these nations. Full article

With growing demand for high-performance and high-efficiency motors, Axial Flux Permanent Magnet Motors (AFPMs) have received significant attention. These motors typically use rare-earth magnets due to their high magnetic and energy density. However, rare-earth magnets face challenges such as limited availability and price volatility, prompting research into reducing magnet usage. This study aims to reduce magnet consumption by applying a Consequent Pole (CP) structure to AFPMs. While CP structures improve magnet efficiency, they also introduce significant back-EMF ripple. To address this, an Intersect Consequent Pole (ICP) structure is proposed, which reduces ripple through alternating magnet placement within the rotor. Since ICP implementation is difficult in single-rotor AFPMs, a double-rotor, single-stator configuration was used. Simulation results show that the proposed design effectively reduces magnet usage and back-EMF ripple, demonstrating its potential for maintaining high performance with reduced rare-earth dependency. Full article

Using time-varying Granger causality, Neural Networks Nonlinear VAR, and Wavelet Coherence analysis, we evidence the unstable effect of the money market rate on industrial production and consumer price index in Tunisia. The effect is asymmetric and depends on geopolitical risk (low versus high). We show that global geopolitical risk has both detriments and benefits sides—it is a threat and an opportunity for monetary policy transmission mechanisms. Interacted local projections (LPs) reveal short–medium-term volatility or dampening effects, suggesting that geopolitical uncertainty might weaken the immediate impact of monetary policy on output and prices. In uncertain environments (e.g., high geopolitical risk), economic agents—households and businesses—may adopt a wait-and-see approach. They delay consumption and investment decisions, which could initially mute the impact of monetary policy. Agents may delay their responses until they gain more information about geopolitical developments. Once clarity emerges, they may adjust their behavior, aligning with the long-run effects observed in the Vector Error Correction Model (VECM). Furthermore, we identify an exacerbating investor sentiment following tightening monetary policy, during global and local geopolitical episodes. The impact is even more pronounced under conditions of high domestic weakness. Evidence is extracted through a novel composite index that we construct using Principal Component Analysis (PCA). Our results have implications for the Central Bank’s monetary policy conduct and communication practices. Full article

Rapid industrialization, widespread transportation electrification, and significantly rising household energy consumption are rapidly increasing global electricity demand. Climate change and dependency on fossil fuels to meet this demand underscore the critical need for sustainable energy solutions. Microgrids (MGs) provide practical applications for renewable energy, reducing reliance on fossil fuels and mitigating ecological impacts. However, renewable energy poses reliability challenges due to its intermittency, primarily influenced by weather conditions. Additionally, fluctuations in fuel prices and the management of multiple devices contribute to the increasing complexity of MGs and the necessity to address a range of objectives. These factors make the optimization of Energy Management Strategies (EMSs) essential and necessary. This study contributes to the field by categorizing the main aspects of MGs and optimization EMS, analyzing the impacts of weather on MG performance, and evaluating their effectiveness in handling multi-objective optimization and data considerations. Furthermore, it examines the pros and cons of different methodologies, offering a thorough overview of current trends and recommendations. This study serves as a foundational resource for future research aimed at refining optimization EMS by identifying research gaps, thereby informing researchers, practitioners, and policymakers. Full article

Textile dye production requires significant amounts of water and chemicals, generating substantial wastewater, which places significant burdens on local environments and water resources. Bangladesh is a global textile dye hub, exporting primarily to the EU and the USA. This research explores Water Unequal Exchange (WUE), which arises when high-income countries (HIC) externalize water use and pollution from consumption and production to low-income countries (LIC), driving environmental degradation beyond their borders. To determine WUE, this paper measures wastewater, groundwater, and chemicals embedded in Bangladesh’s textile trade to the EU and USA between 2000 and 2023. This is based on the net weight of the top 18 textile imports from Bangladesh, provided by the UN Comtrade Database. This paper finds that 3,942,091 million liters of groundwater, 10,792,675 million grams of chemicals, and 2,860,420 million liters of wastewater are embedded in these textile imports. The prices per kg of textiles differ depending on product type, and the highest volume of textile product categories have the lowest price per kg. In conclusion, the textile trade from Bangladesh to the EU and the USA represents a case of WUE, where Bangladesh disproportionately internalizes resource over-extraction and environmental impacts from dye production for low economic gain. Full article

This paper examines whether reference-dependent preferences play a role in determining household electricity consumption in the Korean context. To do so, we first establish six variables of reference costs based on monthly electricity billing information of the 1040 Korean household survey dataset and then test whether these reference costs affect the electricity consumption in the subsequent months using a probit regression analysis. The empirical results show that the residential electricity consumption for the current month is determined by the reference cost in comparison to the actual costs of the previous months. The significant role of reference costs in determining electricity consumption implies that the behaviors of the Korean residential electricity consumers can be explained by the prospect theory. Furthermore, as a policy implication, these results suggest non-price interventions for residential electricity conservation in Korea. Full article

This paper explores optimal consumption and investment strategies for agents facing mortality risk within a complete financial market. Departing from traditional frameworks, we leverage state-dependent utility theory, discounted by the state–price process, to compare consumption streams and utilize life insurance as a strategic hedging instrument. To model the ability of insurance companies to hedge the mortality risk of consumer pools, we introduce the concept of life insurance completeness, allowing individuals to achieve optimal consumption even in scenarios involving negative wealth. Our model relaxes the stringent integrability conditions commonly imposed in the literature, offering a more economically grounded approach to valuation and hedging. We derive a general solution to the optimization problem using martingale techniques under minimal assumptions, demonstrating that life insurance primarily serves as a mortality risk hedge rather than a bequest motive. This perspective resolves longstanding theoretical and empirical challenges, notably the annuity puzzle, by illustrating that optimal consumption and investment, in the absence of labor income, do not necessitate annuities or other life insurance policies. Our key contributions include (1) extending valuation frameworks to encompass prepaid insurance and less restrictive integrability criteria, (2) establishing life insurance completeness for effective mortality risk hedging, (3) demonstrating the feasibility of optimal consumption under negative wealth and state-dependent preferences, and (4) offering a resolution to the annuity puzzle that aligns with empirical observations. Full article

The long-term rise in energy prices leads to reduced consumption, negatively impacting the efficiency of centralized heat supply systems (CHSS). As a result, it is necessary to address the economically inefficient preparation of hot water (HW) at heat transfer stations (HTS). Within the framework of the “Integrated National Energy and Climate Plan” (NECP), which is valid from 2021 to 2030, the industrial sector is aiming to produce 25% of its electricity from renewable energy sources (RES) by 2030. This target, up from 19.2% in 2018, equates to a value of 27.3%, which is at the technical limit of the Slovak electricity system. This article aims to study the installation of PV panels for domestic hot water (DHW) preparation within the central heat supply system (HTS) process, with the decision depending on the results of an economic return analysis. The estimated investment of EUR 5000 excluding VAT would generate annual savings of EUR 311, resulting in a payback period of approximately 16 years. The main limitation is the low efficiency in winter and no production at night, while in summer, a surplus of electricity can be used for preheating cold water. Full article

This study examines the short- and long-term effects of various economic, environmental, and policy factors on renewable energy production (REP) in Saudi Arabia from 1990 to 2024, using the Autoregressive Distributed Lag (ARDL) approach and Vector Error Correction Model (VECM) techniques. The analysis focuses on fossil fuel consumption (FFC), renewable energy investment (REI), carbon emissions (CEs), energy prices (EPs), government policies (GPs), technological advancements (TAs), socioeconomic factors (SEFs), and economic growth (EG) as determinants of REP, measured as electricity generated from solar power sources in kilowatt-hours (kWh). Short-term findings reveal a positive momentum effect, where prior REP levels significantly influence current production, driven by factors such as learning by doing, economies of scale, and consistent policy support. However, FFC negatively impacts REP, highlighting resource competition and market dynamics favoring fossil fuels. Positive short-term influences include REI, CEs, EPs, GPs, TAs, SEFs, and EG, which collectively enhance renewable energy adoption through investments, technological innovation, policy incentives, and economic development. Long-term analysis underscores a strong negative relationship between FFC and REP, with a 7503-unit decline in REP associated with increased fossil fuel dependency. Conversely, REP benefits from REI, CEs, EPs, GPs, TAs, and EG, with significant contributions from technological advancements (3769-unit increase) and economic growth (9191-unit increase). However, SEFs exhibit a slight negative impact, suggesting that rapid urbanization and population growth may outpace renewable infrastructure development. Overall, the study highlights the complex interplay of factors shaping renewable energy production, emphasizing the importance of sustained investments, supportive policies, and technological innovation, while addressing challenges posed by fossil fuel reliance and socioeconomic pressures. These insights provide valuable implications for policymakers and stakeholders aiming to accelerate the transition to renewable energy in Saudi Arabia. Full article

Benzodiazepines (BZDs), potent sedative and hypnotic drugs widely prescribed in psychiatry, pose a high risk of dependence and are globally abused. This study used wastewater-based epidemiology to investigate the consumption patterns of BZDs across four wastewater treatment plants (WWTPs) in Wuhu, China. A total of 16 BZDs and three metabolites were detected in influents and effluents, with concentrations reaching up to 90 ng/L (quetiapine fumarate) and 18.4 ng/L (diazepam). Most BZDs had a poor removal efficiency except quetiapine fumarate (>98% removal). The consumptions of BZDs in WWTPs ranged from <0.02 (lormetazepam) to 2700 mg/day/1000 people (quetiapine fumarate). Seasonal variation was found in BZD usage, where the consumptions in winter and spring were significantly higher than those in summer and autumn. It was worth noting that nimetazepam may be abused during the sampling campaign. Urban areas with higher housing prices match higher BZD consumption, correlating with greater stress and insomnia rates. This study reveals the relationship between socioeconomic factors and BZD consumption patterns, provide a new path to addressing community public health. Full article

Under the guidance of high-quality development goals, the energy industry should not only pay attention to the development level but also to the coordination effect among multiple elements. In the process of low-carbon development, natural gas plays an important transitional role as a clean fossil energy. In this study, by introducing the theoretical perspective of energy trilemma, a comprehensive measurement system of the three-dimensional development level of the regional natural gas industry was constructed. Then, in order to overcome the limitation that the coordination effect is weakened due to the concentration of function values, an improved coupling coordination model was established based on the redefined coupling degree distribution function. Next, based on actual data from Beijing from 2006 to 2022, the safety–economy–environmental protection development level of the natural gas industry was empirically analyzed, and the coupling coordination degree of multi-dimensional factors was deeply investigated. The empirical results reveal the following: (1) Beijing is one of the largest natural gas consumption markets in China, so the economy level of its natural gas industry was relatively high. However, the safety level and environmental protection level needed to be improved. This is mainly due to the scarce resource endowment, and the dependence of economic growth on fossil energy. (2) The coupling coordination degree showed a fluctuating upward trend. The coordination degree of safety and environmental protection was the best, mainly because they coexisted and promoted each other at the policy level. The coordination degree of safety and economy was also relatively high, mainly because supply security could provide resource support for market expansion and stabilize price levels. Meanwhile, a prosperous market would stimulate energy exploration and infrastructure extension. This study will help to provide a high-quality development plan for the natural gas industry for solving the regional energy trilemma. Full article

Field Programmable Gate Arrays (FPGAs), with their wide portfolio of configurable resources such as Look-Up Tables (LUTs), Block Random Access Memory (BRAM), and Digital Signal Processing (DSP) blocks, are the best option for custom hardware designs. Their low power consumption and cost-effectiveness give them an advantage over Graphics Processing Units (GPUs) and Central Processing Units (CPUs) in providing efficient accelerator solutions for compute-intensive Convolutional Neural Network (CNN) models. CNN accelerators are dedicated hardware modules capable of performing compute operations such as convolution, activation, normalization, and pooling with minimal intervention from a host. Designing accelerators for deeper CNN models requires FPGAs with vast resources, which impact its advantages in terms of power and price. In this paper, we propose the VCONV Intellectual Property (IP), an efficient and scalable CNN accelerator architecture for applications where power and cost are constraints. VCONV, with its configurable design, can be deployed across multiple smaller FPGAs instead of a single large FPGA to provide better control over cost and parallel processing. VCONV can be deployed across heterogeneous FPGAs, depending on the performance requirements of each layer. The IP’s performance can be evaluated using embedded monitors to ensure that the accelerator is configured to achieve the best performance. VCONV can be configured for data type format, convolution engine (CE) and convolution unit (CU) configurations, as well as the sequence of operations based on the CNN model and layer. VCONV can be interfaced through the Advanced Peripheral Bus (APB) for configuration and the Advanced eXtensible Interface (AXI) stream for data transfers. The IP was implemented and validated on the Avnet Zedboard and tested on the first layer of AlexNet, VGG16, and ResNet18 with multiple CE configurations, demonstrating 100% performance from MAC units with no idle time. We also synthesized multiple VCONV instances required for AlexNet, achieving the lowest BRAM utilization of just 1.64 Mb and deriving a performance of 56GOPs. Full article

In this study, we investigate whether differences in sociodemographic and housing characteristics may lead to heterogenous reactions on water demand across households in the event of an unexpected shock. In this sense, we estimate a switching regression model for residential water usage in Gijón, Spain, between 2017 and 2021, exploiting the exogenous impact of the COVID-19 pandemic and various movement restriction phases. A rich dataset that integrates real data on water consumption and pricing, alongside reported household and housing characteristics, allows us to effectively control the heterogeneity of water consumers and test changes in marginal effects over time. Our findings reveal a significant increase in average water consumption coinciding with the onset of the pandemic. This increase in water usage was particularly pronounced among households with more members and those residing in older houses that also owned outdoor amenities such as gardens or swimming pools, among other socioeconomic and housing characteristics. Additionally, our study indicates that the price elasticity of water demand did not significantly differ from zero during the periods of the State of Alarm and the New Normal. This suggests that the implementation of movement restrictions and teleworking may have amplified households’ preferences and dependence on water, thus fostering increased water consumption. Furthermore, our results point towards unchanged residential information or knowledge of the expense of water services despite the time spent at home. Full article