Energy Conservation Efficiency Research Articles

Impacts of On-board Energy Storage Devices on the Energy Consumption of Train Operations

Urban rail transit systems consume significant electrical power, with traction accounting for 50% of the total energy (from China Urban Rail Transit Association [1]). As operational mileage and vehicle counts rise, so does energy consumption, underscoring the importance of vehicular energy conservation. This study evaluates the impact of on-board energy storage devices on train energy efficiency. Using operational data from Changsha Metro Line 5 and incorporating literature reviews and simulations, the energy-saving potential was assessed. Integrating these storage devices with vehicle energy monitoring systems shows promising potential for energy conservation and operational efficiency. This research presents a viable strategy to reduce energy consumption in urban rail vehicles, enhancing system competitiveness.

Analysis of the implementation of green building on the Syahdan Campus building based on the Green Building Council Indonesia (GBCI) specifications

Global warming is caused by several factors, one of them being the uncontrolled construction sector that impacts the environment. The concept of green construction and green building is a solution to reduce global warming within the scope of civil engineering buildings. This study determined the criteria and predicate of the results of implementing green buildings according to the Greenship certification by the Green Building Council Indonesia (GBCI) in Binus Syahdan Jakarta. The research method used green building analysis based on the existing greenship building version 1.1. The result is the silver predicate, with the lowest value being Material Resource and Cycle (MRC) and the highest being Energy Efficiency Conservation (EEC). After improvisation, a maximum point was obtained (95) with a platinum predicate. Based on the analysis of the Life Cycle Cost (LCC) calculation for the next 15-20 years, the BINUS Syahdan campus building can save costs of Rp. 7,515,719,282.

Foreign experience in designing energy-efficient hostel buildings

The article discusses the reasons for changing the vector of development of the hotel industry to environmental friendliness and sustainability, reducing energy consumption, reducing greenhouse gas emissions and introducing energy-efficient technologies. Examples of foreign experience in implementing energy-efficient strategies in hostels are provided. Environmental friendliness has become a driving force in the hotel industry, with leading hotel chains trying to meet the demands of consumers who are increasingly paying attention to the climate and are concerned about their environmental impact. According to most definitions, the term "hotel industry" includes not only hotels but also motels, guest houses and hostels. When designing hostels, energy conservation and energy efficiency will save energy resources. Thanks to technology and energy-efficient materials, architectural, planning, and space solutions are being improved. The location and orientation also have an impact on energy saving. The author concludes that in the era of heightened climate awareness, the problem of negative environmental impact is relevant. Tourism alone accounts for a certain percentage of greenhouse gas emissions, which is mostly attributable to the hotel industry. It is necessary to take measures and create conditions to reduce and eventually eliminate the harmful impact on the climate. We see that Western countries are aware of the problem and possible negative consequences, and therefore government institutions are involved in solving this problem by creating relevant regulations, businesses implementing environmental programs, and ordinary hotel visitors who are beginning to prefer more environmentally friendly travel options. However, this influence must be spread to other countries, and this is why information campaigns should be used. Communities, including the scientific community, should pay attention not only to continuing the greening of facilities through the use of energy-efficient technologies, which is a necessary step, but also to finding new options for energy saving and creating new energy-efficient strategies.

Optimization method for multi-process energy consumption in iron and steel enterprises under the coordinated use of comprehensive energy

Sustainable development goals, such as energy conservation, emission reduction, cost reduction, and efficiency enhancement, present pressing challenges for the iron and steel industry. Process optimization technology for efficient production, energy conservation, and consumption reduction in the steel manufacturing process is based on the coordination of material and energy flow. Therefore, this article takes the production process of a converter steelmaking plant as the object, considers the regulatory requirements of multi-process and multi constraint operation optimization under the cooperation of production organization and energy conservation and consumption reduction, and it explores a production scheduling optimization method for steelmaking plants oriented towards material flow and energy flow synergy. Based on the characteristics of the problem space, this study suggests a hybrid genetic algorithm with local search (MOHGALS) that employs both standard and advanced evolution techniques. Tests on concrete problems demonstrate that the MOHGALS approach yields a superior set of multi-objective Pareto schemes. Additionally, random-generated test cases were used to evaluate the algorithm’s performance. The outcomes show that MOHGALS performs better than competing algorithms on multi-objective evaluation indicators, and that the suggested improved evolution approach may effectively boost the algorithm’s performance.

A User-friendly Cloud-based Multi-agent Information System for Smart Energy-saving

<p>The study focused on leveraging artificial intelligence (AI) for efficient energy conservation in scientific applications. The proposed cloud-based multi-agent system merges various intelligent technologies to swiftly gather high-quality cloud data for effective smart energy-saving. Incorporating case-based reasoning (CBR), big data analysis, and intelligent user interfaces as key functionalities, the system utilized Web services, ontology, open data, and data mining. It expanded on the practical advancements of the multi-agent Dr. What-Info system for information collection. A Web services platform seamlessly gathers cloud interactions among subagents processing energy-saving data. Rigorous performance and operational experiments were conducted to demonstrate the efficiency and effectiveness of the system interface, offering detailed insights into relevant R&D technologies and outcomes.</p> <p> </p>

Energy efficiency retrofitting measures of an institutional building: A case study in eastern India

Increasing energy demand and greenhouse gas emissions are major concerns in India. Building energy use in India accounts for 33 % of total energy consumption and is growing at an annual rate of 8 %. In order to save energy, energy conservation in buildings should be given primary importance. Energy conservation practices can reduce energy use in buildings while maintaining thermal comfort. This can be achieved by optimising existing energy use or lowering consumption. One such initiative was undertaken by Siksha 'O' Anusandhan Deemed to be University. It analysed the energy consumption pattern and possible energy conservation opportunities (ECOs) to lower energy usage in its buildings at campus 1 in Bhubaneswar. The Energy Conservation Building Code Odisha (OECBC) was followed to reduce energy use by replacing all the damaged windows with efficient glazing. By following OECBC guidelines, we can save up to 30 % of the energy consumed by an existing building. Besides, energy conservation measures were performed by replacing ceiling fans with brushless direct current (BLDC) fans, existing lights with LED bulbs, and using variable speed drives instead of induction motors. This study will help to define the most efficient energy conservation measures for existing buildings in terms of cost and energy savings. Retrofitting the present building with energy-saving devices will cost INR 21, 32, 90,152 with an overall annual energy savings of 47, 28,177 kWh and a yearly cost saving of INR 319,66,703.

Energy-efficient deep Q-network: reinforcement learning for efficient routing protocol in wireless internet of things

<div align="center"><span>The internet of things (IoT) underscores pivotal real-world applications ranging from security systems to smart infrastructure and traffic management. However, contemporary IoT devices grapple with significant challenges pertaining to battery longevity and energy efficiency, constraining the assurance of prolonged network lifetimes and expansive sensor coverage. Many existing solutions, although promising on paper, are intricate and often impractical for real-world implementations. Addressing this gap, we introduce an energy-efficient routing protocol leveraging reinforcement learning (RL) tailored for wireless sensor networks (WSNs). This protocol harnesses RL to discern the optimal transmission route from the source to the sink node, factoring in the energy profile of each intermediary node. Training of the RL algorithm is facilitated through a reward function that includes energy outflow and data transmission efficacy. The model was compared against two prevalent routing protocols, LEACH and fuzzy C-means (FCM), for a comprehensive assessment. Simulation results highlight our protocol’s superiority with respect to the active node count, energy conservation, network longevity, and data delivery efficiency.</span></div>

Construction of robust silica-hybridized cellulose aerogels integrating passive radiative cooling and thermal insulation for year-round building energy saving

Passive radiative cooling (PRC) is a promising carbon reduction technology that radiates heat into the universe through atmospheric transparency window (ATW) to cool objects below ambient temperature with zero energy consumption. However, so far the cooling efficiencies of most PRC designs are inevitably restrained by inadequate optical properties and parasitic heat gains from ambient air. These defects are overcome by developing aerogel coolers with functional integration of low absorption of solar irradiance, strong mid-infrared emittance, and high thermal insulation in one design. In particular, cross-linked silica-hybridized cellulose acetate is exploited to construct robust aerogels with well-arranged nano/micro porous structures, representing a solar reflectance up to ∼96 % and an ATW emissivity of ∼97 %. Such aerogels can realize a subambient temperature drop of ∼9.15 °C during the daytime and maintain their remarkable cooling performance even in cloudy, moist, and windy climates. The aerogel coolers also show excellent anti-aging, self-cleaning, and compression resistance, making them adaptable for long-term cooling applications. The year-round energy consumption simulations demonstrate that an average total energy saving of 13.87 kW m−2 per year can be promisingly achieved in China when the aerogel coolers are integrated on building roofs. This work paves a new way to manufacture more cost-effective and sustainable cooling materials for efficient building energy conservation in the future.

Genetic tools for the electrotroph Sporomusa ovata and autotrophic biosynthesis.

Sporomusa ovata is a Gram-negative acetogen of the Sporomusaceae family with a unique physiology. This anerobic bacterium is a core microbial catalyst for advanced CO2-based biotechnologies including gas fermentation, microbial electrosynthesis, and hybrid photosystem. Until now, no genetic tools exist for S. ovata, which is a critical obstacle to its optimization as an autotrophic chassis and the acquisition of knowledge about its metabolic capacities. Here, we developed an electroporation protocol for S. ovata. With this procedure, it became possible to introduce replicative plasmids such as pJIR751 and its derivatives into the acetogen. This system was then employed to demonstrate the feasibility of heterologous expression by introducing a functional β-glucuronidase enzyme under the promoters of different strengths in S. ovata. Next, a recombinant S. ovata strain producing the non-native product acetone both from an organic carbon substrate and from CO2 was constructed. Finally, a replicative plasmid capable of integrating itself on the chromosome of the acetogen was developed as a tool for genome editing, and gene deletion was demonstrated. These results indicate that S. ovata can be engineered and provides a first-generation genetic toolbox for the optimization of this biotechnological workhorse.IMPORTANCES. ovata harbors unique features that make it outperform most microbes for autotrophic biotechnologies such as a capacity to acquire electrons from different solid donors, a low H2 threshold, and efficient energy conservation mechanisms. The development of the first-generation genetic instruments described in this study is a key step toward understanding the molecular mechanisms involved in these outstanding metabolic and physiological characteristics. In addition, these tools enable the construction of recombinant S. ovata strains that can synthesize a wider range of products in an efficient manner.

An optimization approach for environmental control using quantum genetic algorithm and support vector regression

Photosynthesis serves as the foundation for vegetable crop yield. It is crucial to appropriately regulate the environmental parameters associated with photosynthesis to ensure efficient production and energy conservation in plant factories or greenhouses. In this research, we proposed a novel optimization approach for determining the target value of environmental control, aiming to balance plant growth and energy cost. By employing hydroponic lettuces as experimental samples, we measured their photosynthetic rates (Pn) under various combinations of four environmental factors: air temperature (AT), nutrient solution temperature (NST), photon flux density (PFD), and CO2 concentration ([CO2]). The photosynthetic data were combined with the support vector regression algorithm to develop a Pn prediction model. This model achieved a coefficient of determination of 0.9748, a root mean square error value of 0.9302 µmol∙m−2∙s−1, and a mean absolute error value of 1.1813 µmol∙m−2∙s−1. The model provide data for subsequent environmental control. The quantum genetic algorithm (QGA) was employed to search the optimal Pn and corresponding PFD, [CO2], and NST at different ATs. The fitness function for QGA was developed considering both the Pn and the energy consumption. This approach could calculate the target environments (PFD, [CO2], and NST) for any given AT. Compared with the Pn maximization approach, the energy cost-saving rate was 1.5 to 3.5 times higher than the Pn loss. The proposed approach could quickly and accurately determine an optimal environmental control target value, outperforming other approaches in complexity and generality. Thus, this study offers an elegant approach to environmental control for hydroponic cultivation.

Ti3C2Tx MXene/delignified wood supported flame-retardant phase-change composites with superior solar-thermal conversion efficiency and highly electromagnetic interference shielding for efficient thermal management

The development of form-stable phase-change material (PCM) with solar-thermal harvest, electromagnetic interference (EMI) shielding, and flame-retardancy is crucial for efficient building energy management and conservation. Herein, novel Ti3C2Tx MXene/delignified wood supported form-stable phase-change composites (PMPCMs) with superior solar-thermal conversion efficiency, highly EMI shielding effects, and excellent flame-retardancy were fabricated by alkaline boiling delignification, ammonium dihydrogen phosphate (ADP) and MXene deposition, and melted n-octadecane impregnation. Benefiting from the powerful surface tension and capillary force of the wood-based support materials, PMPCMs can effectively encapsulate the melted n-alkane molecules and inhibit their leakage. The differential scanning calorimetry results showed that PMPCMs possessed superior n-octadecane encapsulation yield and high thermal energy storage density (166.9–191.6 J/g). Decorating delignified wood by MXene significantly improved the solar-thermal storage efficiency (up to 88.4 %) and EMI shielding performance of PMPCMs. The average EMI shielding effectiveness of PMPCM-10 was enhanced to 34.12 dB in X-band frequency range of 8.2–12.4 GHz. Moreover, with the introduction of the flame-retardant ADP, the peak heat release rate (pHRR) and total heat release (THR) of PMPCMs decreased noticeably, demonstrating the enhanced flame retardancy of delignified wood supported phase-change composites. In summary, PMPCMs exhibited superior application prospects in building energy management and electromagnetic shielding fields.

Solar crop dryer with thermal energy storage as backup heater

In this research work, a solar crop dryer incorporated with thermal energy storage system as backup heater was designed and constructed from locally available materials for drying sorghum. Thermal energy storage (TES) provides several opportunities for efficient energy use and conservation. In the experimental work, flake salt was used as the storage medium to store the heat energy in aluminium pipes. From the experiment conducted on the TES system, the results showed that the dryer reduced the moisture content from about 30% to 11% wet basis in 6 hours. Without the TES, the moisture content could only be reduced from 30% to 13% in 24 hours. The temperature of the TES was found to be between 110 °C and 72.2 °C which was higher than the temperature without TES (40.8 °C to 46.5 °C) for a 24-hour period. Further analysis indicated that the heat storage not only improves the drying but increases the throughput of the device as it can be used at night.

Evaluation of carbon emission efficiency based on urbanscaling law: take 308 cities in China as an example.

The development of urban low carbonization is an important foundation for achieving the goal of "dual carbon." The differences in spatial differences based on scientific methods revealing the characteristics of urban carbon emissions and its efficiency are of great significance for shaping the green low-carbon land space pattern. This article uses urban standard models and scale adjustments to the urban index (SAMIs) identification in 2006-2017 308 Chinese urban carbon discharge standards and efficiency time and space evolution pattern and their characteristics. The results of the study show that there is a stable secondary relationship between carbon emissions and urban population scale, which means that the growth rate of urban carbon emissions is significantly lagging behind the growth of urban systems. The analysis of urban carbon emission efficiency based on SAMI values shows significant spatial heterogeneity: the carbon emission efficiency of cities in North China, East China, and Northeast China is lower than that of other regions. In terms of temporal changes, there was a phenomenon of SAMI high-value cities moving north and low-value cities moving south between 2006 and 2017, and △SAMIs showed a pattern of hot in the west and cold in the east. This study broadens the applicability of urban scaling law models in urban environmental research, providing a new perspective for evaluating urban carbon emission efficiency and China's energy conservation and emission reduction work.

Analysis of the non-linear impact of digital economy development on energy intensity: Empirical research based on the PSTR model

With the rapid development of digital technologies, digital economy (DE) gradually plays a crucial role in changing the pattern of economic and social development. However, the relationship between the DE and energy intensity is still unclear. To fill this gap, this investigation firstly evaluates the development level of the DE of 30 provincial regions in China from 2013 to 2021. Then the non-linear relationship between the DE development and energy intensity is investigated based on the panel smooth transition (PSTR) model taking real GDP, urbanization rate, the proportion of the secondary industry in GDP, R&D funds for industrial enterprises above designated size, and foreign direct investment as transformation variables. The empirical analysis testifies that the DE development can promote the energy intensity and the relationship between the DE development and energy intensity tends to be an invert U shape under the influence of five transformation variables. Values of conversion variables in most provincial regions have not cross thresholds. Especially, the influence coefficients of the DE development on energy intensity have great space to decline under the impact of urbanization rate and the proportion of the secondary industry in GDP. Therefore, the industrial structure should be continuously optimizing and the process of green urbanization should be accelerating. Moreover, it is necessary to stimulate the integration of digitalization technologies and energy system so as to improve energy allocation efficiency and realize energy conservation and emissions reduction.

Evaluation model of energy-saving potential of green buildings by entropy weight method

To estimate the subjective and objective weights of each index, the entropy weight approach was integrated with the analytic hierarchy process in light of the current issues with building energy conservation and sustainable development. This study found that among four indicators, the proportion of environmental sustainability was 48.19%, which had the most significant impact on the energy-saving potential and sustainable development efficiency of buildings. The weight value of the environmental load capacity index was 0.1104. On this basis, the cloud model was used for qualitative and quantitative analysis, and a comprehensive model based on four first-class indicators was established. The study found that the evaluation value of this index showed a kind of volatility, with a peak of 1 and a maximum frequency of 0.6. Overall, it displayed ‘generic’ and ‘good’ traits, demonstrating that people did not give enough thought to the sustainability of the environment and system while pursuing economic and social sustainability. In conclusion, the evaluation method chosen in this study can solve the fuzziness and randomness better in the efficiency of energy conservation and sustainable development of green buildings. This method has a significant impact on the evaluation of real green buildings.

The strategy to achieve zero‑carbon in agricultural sector: Does digitalization matter under the background of COP26 targets?

Under the background of Conference of the Parties (COP26) targets, how to propose sustainable development policies to achieve net zero emissions is very urgent. Internet development has promoted the intellectualization of agricultural environmental governance in China. This paper adopts DEA method and Tobit model to computes the agricultural energy conservation and emission reduction efficiency, and threshold regression model to study the connection between internet advancement and the China's agricultural energy conservation and emission reduction efficiency. The emergence of the internet has a substantial beneficial influence on agricultural energy conservation and emission reduction efficiency, as demonstrated by empirical findings, and this conclusion holds true even after considering potential endogeneity. Moreover, the estimates of the threshold regression model demonstrate the rise of the internet has a double-threshold effect on China's agricultural green total factor energy efficiency (ATFEE). Specifically, the impact of internet advancement on agricultural energy conservation and emission reduction efficiency exhibits a trend of initially increasing and then declining with the regional industrial structure optimization, development of education, and technology enhancement. Therefore, digitalization takes an important part in achieving zero emissions in the agricultural sector.

Efficient and Secure Encapsulation of a Natural Phase Change Material in Nanofibers Using Coaxial Electrospinning for Sustainable Thermal Energy Storage.

In this study, we present an ecofriendly technique for encapsulating lauric acid (LA), a natural phase change material, within polystyrene (PS) nanofibers through coaxial electrospinning. The resulting LAPS core-sheath nanofibers exhibited a melting enthalpy of up to 136.6 J/g, representing 75.8% of the heat storage capacity of pristine LA (180.2 J/g), a value surpassing all previously reported core-sheath fibers. Scanning electron microscopy revealed uniform LAPS nanofibers free of surface LA until the core LA feed rate reached 1.3 mL/h. As the core LA feed rate increased, the fiber diameter shrank from 2.24 ± 0.31 to 0.58 ± 0.45 μm. Infrared spectra demonstrated a proportional increase in the LA content with rising core LA injection rates. Thermogravimetric analysis found the maximum core LA content in core-sheath nanofibers to be 75.0%. Differential scanning calorimetry thermograms displayed a trend line shift upon LA leakage for LA1.3PS nanofibers. LAPS fibers containing 75.0% LA effectively maintained consistent cycling stability and reusability across 100 heating-cooling cycles (20-60 °C) without heat storage deterioration. The core LA remained securely within the PS sheath after 100 cycles, and the LAPS nanofibers retained an excellent structural integrity without rupture. The energy-dense and form-stable LAPS core-sheath nanofibers have great potential for various thermal energy storage applications, such as building insulation, smart textiles, and electronic cooling systems, providing efficient temperature regulation and energy conservation.

Study on the structural evolution and heat transfer performance of Cu supported on regular morphology CeO2 in CO catalytic combustion and chemical looping combustion

Chemical looping combustion (CLC) and catalytic combustion (CC), which are potential technologies to promote CO→CO2 efficient conversion and energy conservation for the steelmaking off-gas, are investigated in reaction activity, structure evolution catalysts/oxygen carriers (OCs) and energy recovery using Cu/CeO2 materials. Activity results suggest that the rod-shaped samples with well-defined (100) crystal faces exhibit higher activity than the sphere-shaped samples with (111) crystal faces, obtaining the optimized copper content of 3 wt%. IR spectra confirmed the proposed reaction pathway that the CO adsorbed on copper sites (Cu+–CO) at the Cu–Ce interface reacts with adjacent surface lattice oxygen. The gaseous oxygen continuously migrates to the external surface of materials, thus resulting in strongly exothermic CO self-sustained combustion during CC. Such a violent reaction does not cause obvious evolution of chemical composition, crystalline phase and structure. Since the active lattice oxygen is gradually consumed but not replenished by external gaseous O2 in time, CO combustion is not self-sustained during CLC. Therefore, the reduction cycle is no longer confined to the surface of the material but penetrates deep into its body, which accelerates Cu+ enrichment at the surface and leads to irreversible sintering and agglomeration of the material.

Salinity-induced changes in plastoquinone pool redox state in halophytic Mesembryanthemum crystallinum L.

We have analyzed the effect of salinity on photosystem II (PSII) photochemistry and plastoquinone (PQ) pool in halophytic Mesembryanthemum crystallinum plants. Under prolonged salinity conditions (7 or 10 days of 0.4 M NaCl treatment) we noted an enlarged pool of open PSII reaction centers and increased energy conservation efficiency, as envisaged by parameters of the fast and slow kinetics of chlorophyll a fluorescence. Measurements of oxygen evolution, using 2,6-dichloro-1,4-benzoquinone as an electron acceptor, showed stimulation of the PSII activity due to salinity. In salt-acclimated plants (10 days of NaCl treatment), the improved PSII performance was associated with an increase in the size of the photochemically active PQ pool and the extent of its reduction. This was accompanied by a rise in the NADP+/NADPH ratio. The presented data suggest that a redistribution of PQ molecules between photochemically active and non-active fractions and a change of the redox state of the photochemically active PQ pool indicate and regulate the acclimation of the photosynthetic apparatus to salinity.

Urban Building Energy Modelling for the Renovation Wave: A Bespoke Approach Based on EPC Databases

In 2020, domestic buildings represented 27% of the energy consumption in the European Union. The EC Renovation Wave concluded that the annual renovation rate should be doubled, from 1% to 2%, over the next decade in order to meet the 2030 energy efficiency targets. Funding programs are being implemented at national and European levels to accelerate this process. These aim to prioritize large-scale interventions and the most efficient energy conservation measures by including strict performance targets as eligibility conditions. However, these programs are coordinated by local authorities, and they struggle to generate reliable energy estimates for large areas, not least predict potential savings at both aggregated and individual levels. This paper presents a bespoke energy retrofit analysis methodology based on urban building energy modelling, which is defined and calibrated with the Energy Performance Certificate Database. We apply this method to the case study Barrio das Flores. The model adopts a hybrid approach, defining and simulating representative typologies to extrapolate the results to the whole district according to each dwelling’s specific parameters. This methodology will be used to predict the potential energy savings in the study area and support the grant application for the funding renovation program.