Potential Energy Savings Research Articles

Cooling Effectiveness of the Sustainable Cooling Solution for Cattle: Case Study in Poland

Recently, the dairy sector has been ever more affected by global warming. This study aimed to test a novel conductive cooling system for cattle that was successfully implemented and evaluated under summer thermally challenging weather conditions in Poland. The system consists mainly of the chiller, tank, and chilled water-driven mattress, designed to prioritize animal well-being. The experimental evaluation was carried out on three Friesian dry cows, housed on different types of bedding—commercial water mattress, straw, and cooling water mattress—and supplied with water at 10 °C (day) and 16 °C (night). The cooling water mattress’ surface temperature was twice as low as that of the commercial water mattress. The animal’s thermal comfort was assessed with physiological and behavioral reactions. The cooling effect on animals’ bodies was demonstrated with a lower reticulorumen temperature of the cooled cow (p < 0.05) than the reference ones. The local effect of cooling was proved with an 8 °C-lower skin temperature after the cow’s resting period. The presented study opens a new research direction toward dairy cattle’s welfare, sustainability, and the food–energy–water nexus, based on potential energy and water savings.

A novel ventilation method: Experimental measurement and numerical simulation of vertical single-row inclined slit ventilation

Existing ventilation technologies often struggle to balance the limited airflow supply with the demands of indoor ventilation and air circulation in winter. This paper introduces a novel ventilation method, vertical single-row inclined slit ventilation (VSISV), which channels airflow through multiple inclined slits spaced at specific intervals along a vertical supply air duct. By ensuring continuity of the upstream and downstream slit jets, a continuous downward airflow is formed, enhancing both winter ventilation performance and indoor air circulation. The method was experimentally measured, with a focus on comparison to the IJV system. At the same airflow rate, it not only efficiently transports the supply air heat from the upper indoor area to the floor but also exhibits strong horizontal diffusion capability. The RNG turbulence model was selected for numerical simulation, focusing on indoor thermal comfort, air quality, and energy-saving potential. The results indicate that, at the same airflow rate, this method effectively maintains high indoor thermal comfort, directs airflow downward from the ceiling, reduces thermal stratification in the upper zone, achieves a more uniform and elevated indoor temperature, enhances indoor air quality, and demonstrates substantial energy-saving potential. This provides valuable insights for energy conservation, emission reduction, and the optimization in winter building ventilation systems.

Energy-Efficient Architectural Design of a Banquet Hall with Integrated Tunnel Ventilation: Monitoring Performance During the Transitional Season in China

The construction industry, a significant contributor to global energy consumption and greenhouse gas emissions, is under considerable pressure to adopt transformative approaches. Public buildings, which account for a substantial portion of total energy usage, must balance high standards of thermal comfort with ventilation efficiency. In China, many public buildings are part of urban landscapes, where façade designs often limit natural ventilation. Consequently, technologies like earth-to-air heat exchangers and wind towers are increasingly essential for enhancing natural ventilation. However, research on the efficacy of these systems remains sparse. This study examines the transitional seasonal environment by evaluating the thermal-humidity index of a banquet hall equipped with an earth-to-air heat exchanger system. Using DeST software [DeST 2.0], the study simulates indoor natural ventilation, calculates ventilation rates, and assesses residual heat removal efficiency. The system’s performance is also modeled under various thermal design zones. Results demonstrate that under natural ventilation, the system can achieve a residual heat removal efficiency of up to 490%. Simulations across different climate zones indicate that the system performs best in regions with extreme temperature fluctuations, particularly those with hot summers and warm winters. In these areas, the system reduces the annual temperature difference by up to 56.7%, significantly improving thermal comfort and reducing dependency on air conditioning. In contrast, performance in milder regions like Kunming achieves only a 37.5% reduction in temperature difference. Overall, this study provides valuable insights into energy-efficient design strategies and thermal optimization for banquet halls, with significant potential for energy savings and enhanced occupant comfort.

Optimising Energy Efficiency in Offshore Buildings: Supporting SDG 7 - Clean and Affordable Energy

The offshore oil and gas sector faces significant challenges in reducing its carbon footprint while meeting global energy demand. Offshore structures consume up to 500 MW of energy per day. Despite the potential for 30-40% energy savings with efficiency technologies, only 25% of global platforms implement integrated energy management systems. This study aims to optimize energy efficiency in offshore structures to support SDG 7 - Affordable and Clean Energy. The study uses a multi-method approach, analyzing data from 10 offshore platforms, conducting energy modeling, and cost-benefit analysis. The results show variability in daily energy consumption (423.7 ± 32.5 MW) with key factors such as hydrocarbon production and environmental conditions. Energy efficiency technologies such as hybrid power generation systems and Integrated Energy Management Systems (SMET) show significant potential for savings. The optimization model shows a total potential energy savings of 37.2 ± 2.1%. Economic analysis using Monte Carlo simulations confirms the feasibility of investment with positive NPV for all evaluated technologies. SMET has the most favorable risk-return profile with a mean NPV of 5.8 ± 0.7 million USD. These findings provide important insights for operators and policymakers, emphasizing the importance of a holistic approach to energy management in offshore structures. Implementation of the proposed energy efficiency strategies can contribute significantly to climate change mitigation and the achievement of SDG 7.

Closed circuits of drip laterals versus open circuits: hydraulic performance and energy-saving potential

Closed circuits of drip laterals versus open circuits: hydraulic performance and energy-saving potential

A fast quadrupole-based analytical model for solving transient heat transfer in ventilated double-skin walls and assessing their energy saving potential

This research proposes a fast and accurate method for modeling transient heat transfer in ventilated double-skin façades (VDFs) with forced ventilation to predict their energy-saving potential. Using the thermal quadrupole formalism, the method solves the VDF problem in the Laplace domain while considering the full transient nature of the heat transfer; the only approximation is in space. The solution involves obtaining a general transfer function that predicts heat transfer rates or air temperatures at ventilated cavity's exit. The quadrupole method is validated against computational fluid dynamic numerical simulations conducted under similar meteorological, design and boundary conditions. A very good agreement was found (less than 3 % average deviation) with a significant reduction in computation time (less than 3s against 6h for CFD calculations). The model is computationally efficient and can consider important factors such as the opacity of the walls, construction materials, and air cavity design parameters. Finally, the model allows the assessment of the energy-saving potential of VDFs under various scenarios compared to conventional systems, which helps contributing to more sustainable building design practices. The energy efficiency of a VDF configuration was compared against a conventional wall system. Energy savings of 8.4 and 5.2 % were obtained, in cold and hot climates respectively.

Thermal Integration in Sugar Production Using Pinch Analysis

Objective: the objective of this study is to conceptualize a network of heat exchangers designed to minimize energy waste and enhance the overall efficiency of the sugar production system.Methods: a systematic approach was adopted to analyze energy flows within the plant, identifying key areas for improvement, particularly in heating and evaporation processes. Heat accumulations in cascades and graphical analyses of composite curves were developed using specialized software to optimize heat exchange.Results: the results indicate a significant potential for energy savings, reducing the consumption of cooling and heating utilities in the plant by 7% and 30%, respectively. The developed computational tool allows for energy integration from simple processes to those with hundreds of streams. The pinch technology concept estimated an annual total savings of $464,850.08 in the selected process.Conclusion: this study demonstrates that thermal integration through pinch analysis not only improves energy efficiency in the sugar industry but also contributes to a considerable reduction in operational costs and environmental impact, providing a valuable tool for the industry’s sustainability and competitiveness.

Simulation and Analysis of Factors Influencing Climate Adaptability and Strategic Application in Traditional Courtyard Residences in Hot-Summer and Cold-Winter Regions: A Case Study of Xuzhou, China

Residential buildings consume significant amounts of energy worldwide. Traditional courtyard houses have substantial energy-saving potential due to their low energy consumption and high climate adaptability, which has heightened interest in their climate-responsive design. In recent years, extensive research on traditional houses has been conducted in China, indicating significant variations in energy performances among traditional courtyards within hot-summer and cold-winter climate zones. Therefore, this study, based on research conducted on traditional courtyard houses in the Xuzhou area and utilizing Ecotect and Phoenics ecotechnology software for simulation analysis, comparatively examines the factors influencing energy consumption to assess the energy-saving potential of these houses in hot-summer and cold-winter climate zones. Research has indicated that when traditional Xuzhou courtyard houses meet certain criteria—including an orientation of 20° east of south for the main building, width-to-depth ratio of 2:1, roof slope of 35°, courtyard width-to-depth ratio of 1.7:1, use of branch pick windows, building height of 4.5 m, and a specific window-to-wall ratio—they achieve optimal climate adaptability. This study proposes dimensions for traditional residential buildings suited to the Xuzhou climate and explores their practical application, providing targeted optimization and retrofitting suggestions to support sustainable architectural and ecological development.

A multi-objective approach to optimizing the geometry and envelope of rural dwellings for energy demand, thermal comfort, and daylight in cold regions of China: A case study of Shandong province

Rural dwellings in China’s cold regions face significant challenges related to energy consumption, thermal comfort, and daylight, with a projected substantial increase in energy demand in the future. Scientifically optimized design during the early planning stages can significantly enhance indoor thermal and daylight conditions, effectively reducing energy consumption. This study focuses on Shandong Province to comprehensively analyze the optimization of geometry and envelope design of rural dwellings in China’s cold regions. It employs a multi-objective optimization method, integrating genetic algorithms with dynamic energy simulations, to minimize total energy demand while ensuring thermal comfort and sufficient daylight. Utilizing the Octopus plugin in Grasshopper, in conjunction with EnergyPlus, Ladybug, and Honeybee, this research optimizes and analyzes the impact of various design variables on energy consumption, thermal comfort and daylight, including room depth, window-to-wall ratio in different orientations, thermal performance of the envelope, and related glass material parameters. The results indicate that the selected variables have significant energy-saving potential. Compared to the case study building, the optimized solutions can reduce total energy demand by over 62.41%, with the highest savings rate reaching 88.75%. This study emphasizes the importance of integrated design and optimization strategies in enhancing the sustainability of rural dwellings. It proposes both cost-free and cost-included optimization schemes: the former maximizes the energy-saving, thermal comfort and daylight potential of the selected variables, while the latter is more practically feasible considering the economic constraints of rural areas. The proposed optimization schemes provide multiple reference solutions and theoretical foundations for users of rural dwellings in China’s cold regions.

Design method of multi-stage air treatment system with circulating air for high efficiency in year-round working conditions

Owing to the large temperature rise/drop during the fresh air treatment process, the multi-stage treatment systems for fresh air have good energy-saving effects. However, the energy-saving potential of multi-stage treatment systems for circulating air and the design of a multi-stage circulating air treatment (MCAT) system that operates efficiently under variable conditions throughout the year remain unclear. Therefore, this study proposed a multi-condition design method to ensure the annual energy-efficient operation of the circulating air system. Firstly, the appropriate number of air treatment stages (NUM) and heat transfer temperature difference between air and water (Δt) for each single condition are determined and an appropriate heat transfer area is obtained. Subsequently, an MCAT system suitable for multiple working conditions throughout the year is designed by searching for the common values of the appropriate heat transfer area per stage. Finally, three types of buildings and six cities located in different climate zones are selected to explore the adaptability of the appropriate Δt. The results show that (1) for each single working condition, the appropriate ranges of NUM and Δt are 1–2 and 2–6 °C respectively, which can keep the system energy consumption at a low level. (2) There is generally a common range for multiple heat transfer areas per stage designed under different working conditions, and an MCAT system designed based on this common range can achieve energy-efficient operation under multiple annual conditions. (3) In an office building in Beijing, compared to the traditional one-stage air treatment system, the maximum and the annual average energy-saving rates of the MACT system designed based on the multi-condition design method are 16.1 % and 6.3 %, respectively.

Analysis of graphene as a potential filtration membrane for desalination at varying operating conditions using molecular dynamics simulation and response surface methodology

ABSTRACT Water scarcity is a critical global issue exacerbated by pollution and overuse, necessitating sustainable water management solutions. Desalination using membrane technology presents a promising approach for freshwater production. This study investigated the performance of nanoporous (NPG) membranes for desalination, focusing on the influence of pressure and temperature on water flux and ion rejection. Utilizing molecular dynamics (MD) simulations with the LAMMPS package, this study evaluates NPG membranes under various conditions of pressures and temperatures. The simulations demonstrate that increasing both the pressure and temperature enhances the water flux without compromising ion rejection. The results indicate that at 300 K and 50 MPa, the water flux exceeds 2000 L/m2 h bar, significantly outperforming traditional reverse osmosis membranes, which typically achieve a capacity of approximately 1 L/m2 h bar. These findings were validated experimentally, aligning with previous research and confirming the superior performance of NPG membranes. A statistical model derived from response surface methodology revealed a linear relationship between pressure, temperature, and water flux. The study concludes that NPG membranes offer a high efficiency and scalable solution for desalination, with significant potential for energy savings and cost reduction. This study underscores the viability of NPG membranes in addressing global freshwater shortages and provides a pathway for sustainable water production.

Experimental study of an absorption-based refrigeration driven by ocean thermal energy

Establishing an island-based cold chain is essential for ensuring food storage, vaccine preservation, and fish freezing on islands, which is indispensable for the sustainable development of island communities. The compression-absorption refrigeration system that uses ocean-thermal-energy is ideal for cold storage on islands as it efficiently utilizes local renewable energy sources and can meet refrigeration needs below 0 °C. Therefore, a refrigeration prototype has been constructed and thoroughly experimentally investigated to obtain refrigeration characterization under variations of refrigeration demand and environmental conditions. The system's energy-saving potential is evaluated by conducting comparisons with conventional refrigeration techniques. The results indicate that refrigeration temperature plays a crucial role in determining refrigeration capacity, with an increase of approximately 8.2 % observed for every 1 °C rise in refrigeration temperature. Lower cold-seawater temperatures or higher warm-seawater temperatures do not have a significant effect on the refrigeration capacity, but contribute to a reduction in compressor power due to increased thermally-driven compression force. Consequently, for every 1 °C change, the refrigeration capacity per unit compressor power increases by approximately 4 %. Additionally, the refrigeration capacity of the system is three times greater than that of a vapor-compression-refrigeration-system. The findings provide theoretical and experimental guidelines for the design and operation of refrigeration using ocean-thermal-energy.

Assessing the Potential of Smart Windows for Energy Efficiency in Tropical Buildings: A Review of Current Research and Future Directions

Abstract Smart windows have energy-saving potential in buildings in tropical climates. Characterized by high solar radiation, humidity, and temperature, tropical climates demand innovative solutions for energy-efficient building design. Smart windows, which can regulate the transmission of light and heat through different thermochromic, photochromic, or electrochromic technologies, are promising to reduce energy consumption in such buildings. Several emerging window technologies, such as gasochromic, hydrochromic, polymer-dispersed liquid crystal, and suspended particle device technologies, also have promising energy-saving potential. However, their high initial costs, durability, and reliability of these technologies limit their applicability. Prospects for smart windows in buildings in tropical climates include advancements in materials science, cost reduction, and integration of smart window technology with other building systems, such as lighting and heating, ventilation, and air conditioning systems. The potential benefits of smart windows for energy-saving s in buildings in tropical climates are substantial, up to 37%. Thus, further research and development in this area would lead to significant advancements in sustainable building design for a better future.

A phase separation prediction model for CO2 capture by biphasic amine absorbents

The biphasic amine absorbent upon absorbing CO2, separates into CO2 poor and CO2 rich phases, making it a third-generation chemical absorbent with energy-saving potential. However, the current method of constructing biphasic amine absorbents involves screening phase separation agents through a large number of experiments, which involves significant amount of trial and error. In this study, a phase separation prediction model was built for CO2 capture by biphasic amine absorbents for quick screening of phase separation agents. The phase separation of CO2 absorption by organic amine 2-amino-2-methyl-1-propanol (AMP) using 34 phase separation agents was statistically analyzed based on 14 molecular descriptors of the solvents. The factors influencing the phase separation were thoroughly explored. It is proposed that the relative dielectric constant or molecular polarity index can replace the traditional polarity evaluation index, dipole moment, to better describe the phase separation situation. Additionally, it is found that the ability of phase separation agents to form hydrogen bonds, particularly as a hydrogen bond donor is the determining factor for phase separation to occur. Ultimately, the preferred molecular descriptors are used as predictors, leading to the development of a prediction model for phase separation that achieves high-accuracy predictions solely through theoretical calculation parameters. The model considerably reducing the construction costs of biphasic amine absorbents.

Development of a georeferenced atlas of energy renovation in residential buildings using GIS tool

Abstract This paper presents a method for modelling the energy needs for heating the residential building stock on a macro scale. The method is based on the use of Geographic Information Systems (GIS) tools to manage various existing geolocalised databases and the collection of field data. It combines the calculation of energy demand with the estimation of solar gains received by the building envelope. In order to estimate the heat energy balance, a description of the building geometry is necessary. The geometrical characteristics of the envelope are extracted from the building entities information available in the spatial database. These parameters are then enriched and cross-referenced with other data gathered from the government’s complex taxation files. The TABULA buildings typology was chosen because it is an exhaustive European classification adapted for use in GIS utilities. The objective of this work is to produce a georeferenced atlas that can identify potential energy savings on large zones, such as urban areas. An understanding of energy consumption at this scale is crucial for the effective management of massively scaled energy-saving solutions. The atlas will promote energy efficiency in the residential sector and guide environmental policy measures by identifying priority areas for renovation.

Enhancing indoor thermal comfort prediction in tropical regions: A transfer learning strategy in West Bengal

Ensuring energy-efficient building management and sustainability necessitates precise thermal comfort prediction, a task particularly critical in tropical regions with significant energy-saving potential. This study confronts the complexities introduced by humid air conditions and escalating internal and external heat levels. The objective is to devise a sophisticated strategy for predicting indoor personal thermal comfort that enhances prediction accuracy. The proposed method extends beyond previous techniques by incorporating a comprehensive array of thermal comfort factors and their potential interdependencies, while also leveraging a transductive transfer learning strategy to circumvent data sparsity in the target domain. The experimental results indicate the presence of localized feature coupling within thermal comfort datasets, which the proposed CNN-ConvTrans model effectively processes, thereby enhancing predictive efficacy. The primary innovation of this work lies in the development of a novel transfer learning strategy that considers localized feature coupling, integrated with a deep learning model, effectively addressing issues such as class imbalance and data scarcity. This study furnishes an innovative and valuable framework for thermal comfort prediction across diverse environmental settings.

A comparative performance study of terminal control strategy for the multi-split backplane cooling system in data centers

Multi-split backplane cooling, a typical rack-level cooling technology, has the advantage of solving local hot-spot problems with huge energy-saving potential. These systems adopt the multi-split mode, and the operation effect is affected by terminal control performance. However, there are factors in the operation process, such as superheat degree (SH), rack airflow, evaporating/condensing pressures, etc., which improve the control complication, particularly under large head load differences among different terminals. Therefore, appreciative control strategies for outlet air temperatures of terminal evaporators, including single-loop control limited by minimum stable superheat degree (SLC) and fan/electronic expansion valve (EEV) double-loop control (DLC), are proposed considering that cooling performance can be affected by both refrigerant flow and airflow. Then, comparative simulation studies are carried out to evaluate energy efficiency, control effect, and feasibility under the condition of different server heat distribution characteristics. Results indicate that the DLC strategy achieves 23% higher energy efficiency than the SLC strategy with a better temperature control effect when the inlet air temperature (IAT) difference between terminal evaporators is within ±5K. The SLC strategy has better reliability by more stable control of SH at IATs below 42°C, but it may lead to cooling failure when IATs exceed 42°C. An insufficient liquid supply problem may happen to the evaporator adopting the DLC strategy when the IAT is too high, which can be solved by adjusting the pressure differential between the evaporator and condenser. Moreover, the DLC system exhibits intense coupling effects, and how to decouple it is worthy of further study.

Energy-efficient optimization design of bio-butanol fermentation broth purification process

To address the downstream processing challenges of the IBE (isopropanol-butanol-ethanol) system and obtain biobutanol products with a mass fraction of 0.9999, as well as obtain a mass fraction of 0.99975 for the IE (isopropanol-Ethanol) mixture product as a gasoline additive, this study proposes a four-column distillation process termed "Dehydration-Butanol-Extractive Four Column Distillation" (DBE-4CD). With the heat load as the optimization target, the DBE-4CD process was optimized to determine the optimal operating parameters. Based on the optimized process and considering the energy-saving potential of the dividing wall column, an “Azeotropic Dividing Wall-Extractive Three Column Distillation” (ADE-3CD) process was subsequently proposed to further enhance energy efficiency and reduce consumption. Compared to both conventional literature process and the DBE-4CD process, the total load of the ADE-3CD process decreased to 7433.5 kW, representing reductions of 20.35% and 10.11%, respectively. Additionally, the mass recovery rates of butanol and the IE mixture reached 99.90% and 99.64%, respectively, exceeding those of the conventional literature process, which were 99.11% and 99.18%.

Energy Efficiency and Sustainability in Food Retail Buildings: Introducing a Novel Assessment Framework

One of the primary global objectives is to decrease building energy consumption to promote energy efficiency and environmental sustainability. The large-scale food retail trade sector accounts for over 15% of total primary energy consumption in Europe, posing a significant challenge to the transition towards green energy. This study proposes a simple method for energy efficiency, environmental sustainability, and cost-saving assessment and improvement in large-scale food retail trade buildings. It aims to analyze the energy and environmental performance of building–plant systems, establishing an interactive network to assess intervention potential for the energy transition. The investigation focuses on the proper selection and analysis of the benefits of retrofit solution implementation, emphasizing potential energy savings in current and future climate change scenarios. Dynamic simulation with the Building Energy Model (BEM) was used to evaluate the impacts of building–plant system retrofit solutions, such as high thermal insulation, photovoltaic (PV) panels, Light Emitting Diode (LED) installation, waste heat recovery, and improvement in refrigeration units. The results show a reduction in annual energy consumption for the PV panel installation by up to 29% and lighting systems with high-quality LED to 60%. Additionally, CO2 emissions can be decreased by up to 41% by combining these two strategies.

Effect of moisture (2 mol%) on CO2 enhanced desorption from nano-dispersed Na2O/Al2O3 for direct air capture

This study demonstrates enhanced CO2 desorption from nano-dispersed “Na2O”/γ-Al2O3 using a low moisture content purge gas. As little as 2 mol% moisture (generated at the vapor pressure of water at 20 °C) present in an inert purge gas enhances the amount and rate of CO2 desorbed over a series of temperatures relative to a dry purge. Multi-cycle aging tests of 317 h, at various desorption conditions, confirmed the stability of system efficiency with the potential for energy savings in avoiding steam production commonly used for CO2 desorption.