Search Results (301)

This study investigates a water–energy investment in the Consorzio di Bonifica della Romagna Occidentale (Northern Italy) over the period 2015–2022, analysing how integrated irrigation and energy infrastructures can support agricultural resilience. In this area, pressurised irrigation systems are increasingly replacing traditional gravity-fed networks, enabling precise water distribution. However, their energy intensity raises operational costs and exposure to volatile electricity prices. To address these challenges, the research evaluates the coupling of pressurised irrigation with floating photovoltaic (PV) systems on irrigation reservoirs. Using plot-level economic data for vineyards and orchards, the analysis shows that, although pressurised systems entail higher costs in terms of Relative Water Cost (RWC) and Economic Water Productivity Ratio (EWPR), integrating them with PV production significantly improves economic performance. The findings show an average reduction in RWC of 1.44% for vineyards and 5.52% for orchards, and an average increase in EWPR of 38.51 units for vineyards and 24.81 units for orchards. This suggests that combining efficient irrigation systems with renewable energy could represent a viable pathway toward more sustainable water management. Policy implications may concern incentives for joint water–energy investments, adjustments to zero-injection rules, and broader reforms in agricultural, energy, and environmental policies. Full article

In this study, an Integrated Energy System (IES) with hydrogen refinement within a tiered carbon trading mechanism (TCTM) is presented to improve energy efficiency and support decarbonization. To address uncertainties in the IES, a distributionally robust optimization (DRO) approach, employing a fuzzy set framework with Kernel Density Estimation (KDE) to construct error distributions and specify output ranges for renewable energy (RE), is proposed. Latin hypercube sampling (LHS) and K-means clustering are, respectively, applied to generate original and representative scenarios. Subsequently, case studies are performed to evaluate advantages of the presented model. The results indicate that hydrogen refinement within the TCTM framework has substantial benefits for the IES. Specifically, the proposed scenario integrates hydrogen blending combustion (HBC) with synthetic methane, demonstrating significant economic and carbon benefits, with cost reductions of 7.3%, 7.1%, and 4.3% and carbon emission reductions of 6%, 3%, and 2.4% compared to scenarios with no hydrogen utilization, HBC only, and synthetic methane only, respectively. In contrast, to exclude carbon trading and include fixed-price trading, the TCTM achieves a 3.5% and 1.1% reduction in carbon emissions, respectively. Finally, a comprehensive sensitivity analysis is performed, examining factors such as the ratio of hydrogen blending, price, and growth rate of carbon trading. Full article

The CO₂ capture process in coal-fired power plant flue gas still faces the difficulties of low material performance and high energy and cost consumption. It is necessary to develop new capture solvents and materials, and also new capture process configurations, to achieve breakthroughs in capture performance and process technology. In various process configurations for CO₂ absorption, lean solution vaporization and compression (LVC) is a commonly used and effective one for reducing the energy and cost consumption. This work propose a partial lean solution vaporization and compression (PLVC) configuration to decrease energy and cost consumption for CO₂ capture, considering the price difference in heat and electricity with the high prices of compressors. The three heat exchange methods of no heat exchange, separate heat exchange, and merged heat exchange for lean solution after flash evaporation are also proposed with PLVC, which could be used in the range of low (0–25%), middle (25–75%), and high split ratios (75–100%) of lean solution for the lowest total heat consumption of the aqueous AMP + PZ solvent. Therefore, the comprehensive cost of the capture process can be minimized by considering different prices of steam heat, electricity, and compression facility. Full article

Time-of-Use (TOU) tariffs are a primary driver for deploying demand-side energy storage, yet their specific structural characteristics, such as peak-to-valley ratios, and the presence of critical-peak pricing, can significantly influence the economic viability of hybrid storage systems. In addition, the continuous decrease in storage capacity costs also constitutes a major influencing factor on storage investment portfolios. This study investigates the sensitivity of optimal hybrid storage portfolios to varying TOU tariffs and storage costs. We develop a multi-scenario optimization framework that models diverse, realistic TOU tariff structures and evaluates their impact on the life cycle economic performance of hybrid storage in a representative office building. The methodology leverages a refined daily operation optimization model that accounts for storage degradation and system efficiencies, applied across a set of typical operational days. The impacts of specific tariff parameters (e.g., peak-to-valley ratio, critical-peak pricing) and storage costs on the optimal allocation of investment between battery and cooling storage are investigated. The thresholds of tariff and capacity cost that trigger a shift in investment preference are identified. The findings provide actionable insights for policymakers on designing effective dynamic tariffs to incentivize specific storage technologies and for building owners formulating future-resilient storage investment strategies. Full article

Global energy markets have experienced persistent dispersion in real energy prices, creating structural competitiveness pressures that standard indicators often fail to capture in real time. These pressures have intensified as energy-intensive sectors face asymmetric exposure across advanced and emerging economies. This study addresses two critical gaps in international energy cost competitiveness. The first is a frequency gap: conventional indicators such as the Real Unit Energy Cost (RUEC) are typically published with delays of 2–5 years, limiting their usefulness for timely policy evaluation. Here, both RUEC and the Real Price Level Index for energy (Real PLI)—the ratio of the Purchasing Power Parity (PPP) for energy to that for GDP—are measured with only a 2–3-month lag for nine countries—four in Asia, four in Europe, and the U.S. The second is a competitiveness gap that calls for policy responses. Real PLIs indicate that the energy price disadvantages of Japan, Korea, France, Germany, Italy, and the UK have widened from 1.76–2.91 times the U.S. level before the pandemic to 2.14–3.28 times by Q3 2025, with the gaps relative to China and India also widening. Once country-specific thresholds are exceeded, output in energy-intensive and trade-exposed (EITE) industries tends to contract disproportionately. These findings highlight that sustainable transitions require not only internationally differentiated burden-sharing but also structural reforms to avoid persistent widening of energy price gaps. The Real PLI framework provides a timely indicator of competitiveness and an early-warning tool, signaling when growing asymmetries may undermine policy feasibility. Policy implications include the need to monitor real energy price dispersion as a core source of competitiveness risk, to strengthen structural measures that stabilize marginal energy costs, and to design transition pathways that account for heterogeneous adjustment pressures across countries. Full article

With increasing renewable energy integration, electricity spot markets exhibit high volatility and uncertainty, making it difficult to balance profit and risk. To address this challenge, this paper proposes Joint (Version 1.0), a multi-agent closed-loop framework that integrates forecasting, strategy, and feedback for coordinated decision-making. The Prediction Agent learns statistical patterns of price spreads to generate distributional forecasts, directional probabilities, and extreme-value indicators; the Strategy Agent adaptively maps these signals into executable bidding ratios through a hybrid mechanism; and the Feedback Agent incorporates settlement results for performance evaluation, CVaR-based risk control, and preference-driven optimization. These agents form a dynamic “forecast–strategy–feedback” loop enabling self-improving trading. Experimental results show that Joint achieves a monthly profit of 146,933.46 CNY with strong classification performance (Precision = 53.25%, Recall = 40.45%, AA = 56.05%, SWA = 57.36%), and the complete model in ablation experiments reaches 157,746.64 CNY, demonstrating the indispensable contributions of each component and confirming its robustness and practical value in volatile electricity spot markets. Full article

This study presents the development, purification, and performance evaluation of a biogas-powered electricity generation system designed for medium-scale swine farms. A conventional Hino V-22C diesel engine was modified to operate in spark-ignition mode using purified biogas with methane content ranging from 65 to 70%, obtained through a PSA upgrading system. The compression ratio was reduced from 18.5:1 to 14.7:1 to accommodate the lower heating value and combustion characteristics of biogas. An oxygen-sensor-based emergency fuel supply (EFS) system was integrated, activating when λ > 19.0 and deactivating when λ < 17.0, to enhance combustion stability under high-load operation. The corrected higher heating value (HHV ≈ 20–21 MJ/kg) and consistent fuel mass flow rate (0.036 kg/s) were used for revised thermodynamic calculations. Field testing over 524 operating hours demonstrated stable power generation between 80 and 120 kW. The EFS system increased thermal efficiency by approximately 22.7%, achieving a peak efficiency of 11.66% at 100 kW. A techno-economic assessment, including sensitivity analysis (±20% biogas yield and ±10% electricity price), confirmed economic viability with a breakeven period of 15.79 months. The system offers a reliable and scalable renewable energy solution for agricultural applications, contributing to methane mitigation and improved waste-to-energy utilization. Full article

Many electricity providers are offering their customers an array of tariff options intended to discourage electricity consumption at specific times of the day. The problem facing a customer is whether to switch from their existing tariff to a new tariff. The aim of this paper is twofold: first, to develop two analytical methods that help residential customers evaluate when switching from a flat-rate tariff to time-varying pricing options, specifically the Time-of-Use (TOU) tariff and an event-based tariff, becomes economically beneficial, and second, to review customers’ experiences with the tariffs. The methods identify the specific consumption distributions at which the TOU or event-based tariffs are in energy- and cost-equilibrium with the domestic service tariff for residential customers. For the TOU structure, the analysis shows that customers must maintain a non-winter-to-winter-peak consumption ratio exceeding 3.0756 for cost neutrality, a condition rarely met by households with winter-dominant loads. In contrast, event-based structures require only minimal behavioral adjustments to achieve savings, with as little as 1.75% of annual consumption needing to be avoided during event periods to match domestic-service costs. Additional savings are observed with partial or full load shifting away from peak events. The findings highlight that while TOU may benefit households with high summer usage, event-based tariffs present a more practical and economically favorable option for residential customers living in the Canadian province of Nova Scotia. The paper concludes with implications for tariff selection and consumer behavior. This research will be of value to anyone considering designing a time-varying rate or having to choose between an existing flat-rate tariff and a time-varying tariff. Full article

This study investigates the relationship between emission performance, environmental disclosure, and firm value in Southeast Asia, where climate-related risks are increasingly shaping corporate strategies and investor decisions. Using a sample of 206 listed firms from Indonesia, Malaysia, Singapore, and Thailand over 2022–2023, the analysis applies a 12-item environmental disclosure index and emission scores from Refinitiv LSEG, with firm value measured by the price-to-book ratio. Structural Equation Modeling (SEM) is employed to test causal pathways, complemented by ANOVA to explore cross-country and cross-industry differences. The results show that emission performance significantly enhances environmental disclosure, consistent with signaling theory and the resource-based view, where superior performance motivates firms to communicate credibility and differentiate themselves. However, environmental disclosure does not exert a significant direct effect on firm value, highlighting a disclosure–value gap in emerging markets where reporting remains heterogeneous and less valued by investors. Country-level differences suggest stronger performance in Indonesia, Singapore, and Thailand compared to Malaysia, while industry-level analysis shows that health care, energy, and financial firms lead in both emission management and disclosure. The findings provide implications for regulators, firms, and investors by underscoring the need for stronger ESG reporting frameworks and more credible disclosure practices to strengthen value relevance. Full article

Within the energy system, agriculture represents a distinct sector, as it functions both as a consumer of energy derived from fossil fuels and renewable sources and as a producer of renewable energy. Since energy consumption is closely linked to production intensity and cost efficiency, energy costs have a direct impact on farm profitability and financial stability. The aim of the study is to analyze and assess the relationships between energy costs and the financial situation of farms in Poland in comparison to the European Union average, based on data from the Farm Accountancy Data Network (FADN) and its successor, the Farm Sustainability Data Network (FSDN), covering the years 2014–2023. The study focuses on differences in the structure and burden of energy costs and their implications for the economic performance and financial resilience of agricultural holdings. The comparative analysis revealed that farms in Poland are characterized by a higher share of energy costs in total production costs and a higher ratio of energy costs to total income compared to the EU average, indicating lower financial resilience to energy price volatility. These findings suggest that measures aimed at improving energy efficiency, supporting technological modernization, and encouraging the adoption of on-farm renewable energy could strengthen the long-term stability and competitiveness of Polish agriculture. Full article

The search for sustainable alternatives to synthetic composites has become increasingly relevant in aerospace engineering education and student rocketry. Fiberglass is widely used for rocket fuselages due to its favorable balance of performance and cost, but it is energy-intensive, non-biodegradable, and environmentally burdensome. This study provides the first demonstration of natural fiber composites applied to student rocket fuselages, evaluating bamboo and jute as sustainable alternatives to fiberglass. Fiberglass, bamboo, and jute laminates were fabricated following the procedures of the RocketWolf team at CEFET/RJ. The fuselages were characterized by parachute ejection tests, surface roughness analysis, and flight simulations using OpenRocket software. Additional data such as laminate mass, wall thickness, fiber–resin ratio, and cost analysis were incorporated to provide a comprehensive assessment. Results revealed contrasting behaviors: untreated bamboo composites showed poor resin impregnation, brittle behavior, and lack of structural stability, confirming their unsuitability without chemical treatment. Jute composites, in contrast, achieved adequate impregnation, cylindrical geometry, and superior surface roughness (Ra = 37 µm) compared to fiberglass with paint (62 µm) or envelopes (52 µm). Both fiberglass and jute fuselages successfully passed parachute ejection tests, while simulations indicated apogees close to 1 km, fulfilling competition requirements. The jute fuselage also presented slightly improved stability margins. Economically, jute was ~492% cheaper than fiberglass in fiber-only comparison but absorbed more resin; nevertheless, real purchase prices favored jute. These findings confirm that jute composites are a technically feasible, cost-effective, and sustainable substitute for fiberglass in student rocket fuselages. Beyond technical validation, this work demonstrates the educational and environmental benefits of integrating natural fibers into academic rocketry, bridging sustainability, performance, and innovation. Full article

Against the backdrop of the full market integration of renewable energy, determining a reasonable proportion between medium- and long-term (MLT) contracts and spot trading has become a core issue in power market reform. Current Chinese policy requires that the share of MLT contracts should not be less than 90%, which helps ensure system security but may suppress the price discovery function of the spot market and limit renewable energy integration. This paper constructs a three-layer model: the first layer describes spot market clearing through Direct Current Optimal Power Flow (DC-OPF), yielding system energy prices and nodal prices; the second layer models bilateral contract decisions between generators and users based on Nash bargaining, incorporating risk preferences via a mean–variance framework; and the third layer introduces two evaluation indicators—contract penetration rate and economic proportion—and applies outer-layer optimization to search for the optimal contract ratio. Parameters are calibrated using coal prices, wind speed, solar irradiance, and load data, with numerical solutions obtained through Monte Carlo simulation and convex optimization. Results show that increasing the share of spot trading enhances overall system efficiency, primarily because renewable energy has low marginal costs and high supply potential, thereby reducing average market prices and mitigating volatility. Simulations indicate that the optimal contract coverage rate may exceed the current policy lower bound, which would expand spot market space and promote renewable energy integration. Sensitivity analysis further reveals that fuel price fluctuations, renewable output, load structure, and risk preferences all affect the optimal proportion, though the overall conclusions remain robust. Policy implications suggest moderately relaxing the constraints on MLT contract proportions, improving contract design, and combining this with transmission expansion and demand response, in order to establish a more efficient and flexible market structure. Full article

With the increasing share of renewable energy, green power parks face challenges such as high electricity purchasing costs and fluctuations in power quality. To address these issues, this paper proposes an integrated optimization method based on power quality responsibility modeling and a differentiated reward–penalty pricing mechanism (DRPPM). First, an integrated operation model of “source–grid–load–storage” is established. Within the pressure–state–response (PSR) framework, power quality deviations are quantified and mapped into economic costs. Then, a differentiated reward–penalty pricing mechanism is designed to dynamically adjust power quality deviations through a continuous function, guiding users toward adaptive energy consumption behavior. Finally, a green power park in Gansu Province dominated by wind and photovoltaic generation is used as a case study with four typical simulation scenarios. The results show that the proposed mechanism reduces the park’s electricity purchasing cost and increases the green power consumption ratio by up to 74.9%. Meanwhile, it effectively improves power quality indicators such as frequency, voltage, and harmonics. The study verifies the comprehensive advantages of the proposed framework in terms of economy, energy efficiency, and stability, providing a reference for low-carbon and efficient operation of high-energy-consumption green power parks. Full article

The oil sector in Ecuador represents one of the largest national energy consumers, with significant contributions to greenhouse gas and thermal emissions due to reliance on diesel-based thermoelectric generation. This study assesses the feasibility of implementing waste heat recovery processes in upstream petroleum operations, aiming to improve energy efficiency and reduce the sector’s carbon footprint. Historical production and energy consumption data (2015–2020) from the main oil blocks (43-ITT, 57-Shushufindi, 57-Libertador, 58-Cuyabeno, 60-Sacha, and 61-Auca) were analyzed, alongside experimental parameters from thermoelectric equipment. Key energy indicators, including recoverable heat potential, energy intensity, and CO₂ emissions, were quantified to identify inefficiencies and opportunities for recovery. Results show that blocks with the highest crude production also exhibit the largest energy demand, with flue gas temperatures averaging 400 °C and an estimated recovery potential of up to 1.9 MWe through Rankine Cycle systems. Pre-feasibility analysis indicates a cost–benefit ratio of 1.03 under current conditions, which could reach 1.29 with higher load factors, while avoided emissions surpass 7000 tCO₂ annually. The findings highlight a strong correlation between energy intensity and CO₂ emissions, emphasizing the environmental relevance of recovery projects. Adoption of heat recovery technologies, coupled with regulatory incentives such as carbon pricing, offers a viable pathway to enhance energy efficiency, reduce operational costs, and strengthen sustainability in the Ecuadorian oil industry. Full article

The coffee industry generates wastewater with high organic loads, which represents both an environmental challenge and a potential resource. This study proposes a novel, integrated solution for an instant coffee plant in Ecuador by incorporating anaerobic digestion into the treatment train. The approach uniquely combines rigorous kinetic analysis with a comprehensive techno-economic and sustainability assessment. Long-term operation of upflow anaerobic filters confirmed the superior stability and performance of the mesophilic regime. Under these conditions, the process achieved a methane yield of 200.5 mL_CH4 g⁻¹_COD and a chemical oxygen demand (COD) removal efficiency of 64.1%. The experimental data fitted to the modified Stover–Kincannon and Grau second-order kinetic models (R² > 0.95) validating the robustness of the mesophilic operation. For the technological proposal, a hydraulic retention time of 7.3 days and an organic loading rate of 1.03 kg_COD m⁻³ d⁻¹ were established. The economic evaluation confirms that a minimum price of USD 171 per 60 kg_bag is required to achieve a positive net present value with a payback period of 5.47 years. Furthermore, the system transitions the facility’s energy profile to net-positive status, with an energy recovery ratio of 1.67, and strengthens the environmental sustainability of the proposal. It is concluded that anaerobic digestion is a viable technology from technical, economic, and environmental perspectives, enhancing the performance of the instant coffee industry and generating added value from highly polluting waste. Full article