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Research has revealed the existence of an energy-efficiency gap – the difference between optimal and actual energy end-use, suggesting that energy efficiency can be improved. Energy management (EnM) is a means for improving industrial energy efficiency. However, due to various barriers, the full potential of EnM is not realised. Several studies have addressed drivers and barriers to energy efficiency but few to EnM. This study aims to identify EnM practices, the most important perceived drivers and barriers for EnM, and relations among them in the energy-intensive Swedish pulp and paper industry (PPI), which has the longest experience internationally of practising EnM systems, and has worked according to the standards since 2004. Our results show that, altogether, the PPI works regularly and continuously with EnM, with a clear division of responsibilities. The highest maturity for EnM practices was for energy policy, followed by organization, investments, and performance measurement. The study also shows that communication between middle management and operations personnel has potential for improvement. The most important categories of drivers were economic, whereas for barriers they were organizational. Nevertheless, knowledge-related barriers and drivers were amongst the most important, suggesting that the absorptive capacity for energy issues could be improved. Image 1029 • Energy is managed continuously, with clear policies and responsibilities. • The main drivers are economical while main barriers are organizational. • Knowledge related barriers and drivers are amongst the next most important. • Employees' absorptive capacity for energy issues could be improved. • Link between energy policy and performance measurement could be improved. [ABSTRACT FROM AUTHOR]

Guiding industries to produce in an effective and environmentally sustainable manner has become a key issue for governments around the world. Over the past 15 years, series of regional and industrial development policies have been introduced by the Chinese government. This has influenced the geographical distribution and energy efficiency performance of China’s industries. This paper quantifies the influence of enterprises geographical distribution on energy efficiency improvement in the paper industry and aims at providing some helpful suggestions on industrial development to policy makers. The main results show that, firstly, the paper industry in eastern China shows obvious characteristic of agglomeration. The average location quotient is 1.2278. However, following the industrial and regional development policies, the characteristic of agglomeration is weakening. Secondly, only when agglomeration reaches a certain level (location quotient is above 0.5447) will industrial agglomeration positively impact on industrial energy efficiency improvement (a 1% increase in agglomeration will increase dynamic energy efficiency by at least 0.23%). Thirdly, the regional development policies carried out by the government slow the pace of energy efficiency improvement in China’s paper industry. The empirical results indicate that the government needs to consider regional characteristics and consciously guide industrial enterprises to concentrate in the dominant area. [ABSTRACT FROM AUTHOR]

The advancement in plastic and plastic based products in last two decades has imposed a serious threat to the environment. This has led to an increase in the demand for sustainable and biobased products. Paper and paper products are good alternatives to their plastic counterparts. A key element of paper industry is the raw material (wood, bamboo and nonwood agricultural residues such as bagasse, straws etc.) from which pulp is produced. The pulp is then utilized for production of paper. There are many pulping processes to prepare pulp of various qualities. For fine grade pulp, chemical pulping is used. The chemical pulp is produced by soda, kraft and sulphite pulping processes. However, for newsprint grade pulp, stone ground wood (SW), thermomechanical (TMP), chemi-thermomechanical (CTMP), chemi-mechanical (CMP) or refiner mechanical (RMP) corresponding pulping processes are employed. The method of pulp preparation (pulping process) consumes large amount of energy and chemicals. A new pulping process with electron irradiation using biowaste (bagasse) as a raw material is discussed in this work. Bagasse pulping process is found to reduce about 50% of energy consumption during pulping process. The process is referred to as 'ECTMP' (Energy Efficient Chemi-Thermo Mechanical Pulping). The paper produced from aforesaid method also reflected no loss of strength properties with respect of TMP reference pulps. Henceforth, preliminary calculation based on experimental results shows that the proposed bagasse ECTMP process explored the scope of energy savings of the order of 50%. • Energy efficient thermochemical process for biowaste conversion into paper was explored. • The effects of high energy electron irradiation pre-treatment were investigated. • Chemical pretreatment improved the strength properties of paper. • Specific energy consumption of bagasse pulping was significantly reduced. • The approach of pre-irradiation can be implemented for other raw materials also. [ABSTRACT FROM AUTHOR]

China’s paper industry consumes a lot of energy and emits huge amounts of pollutions. The Chinese government over the past decades has done a lot to promote energy efficiency of the industry. This paper studies the impact of industrial polices to improve energy efficiency. The energy efficiency change is firstly studied under a framework of total factor efficiency. On this basis, different econometric models are built to discuss the detailed energy efficiency characteristics of the paper industry. The main results are as follow: (i) ownership structure did influence the energy efficiency, but the influence is different in different conditions; (ii) energy efficiency of the paper industry can be improved by economies of scale; (iii) market competition can to some extent overcome the motivation and supervision problem that often occur in state-owned companies; (iv) energy price cannot play the role of resource allocation well in China. Finally, based on our findings, some suggestions are provided. [ABSTRACT FROM AUTHOR]

The papermaking industry has developed rapidly in recent years in China. Papermaking is a high-energy-consuming process. Consequently, large-scale paper mills usually have cogeneration systems that supply both electricity and steam for the papermaking process. In China, almost all these cogeneration systems in paper mills are powered by coal combustion, which consumes a large amount of energy and emits large amounts of greenhouse gas. The Integrated Gasification Combined Cycle (IGCC) technology is regarded as a clean and efficient method of coal utilization. In this work, an IGCC process for application in paper mills was designed and modeled. An IGCC coupled with a cascade refrigeration process (CRP) was further proposed in order to reuse the waste heat from the dryer section and improve the energy efficiency of the papermaking process. A paper with a conventional cogeneration system, one with an IGCC cogeneration system, and one with an IGCC coupled with a CRP cogeneration system were analyzed and compared in terms of energy efficiency, capital investment, operational cost, and dynamic payback period. The results showed that the integration of IGCC technology allows paper mills to be more competitive than those featuring conventional cogeneration systems in terms of energy efficiency and operational cost. [ABSTRACT FROM AUTHOR]

Abstract: The purpose of this study was to assess the environmental impacts of the Norwegian pulp and paper industry, considering the production of pulp fibres and printing paper. The pulp fibres included in this study are thermo-mechanical pulp and kraft pulp fibres, which differ with respect to the energy consumption and chemicals used during production. The assessed paper grades were super-calendered paper and newsprint. The study was a cradle to gate approach, and corresponds to an attributional life cycle assessment (LCA). The LCA was based on data collected from main pulp and paper producers in Norway. Importantly, aspects related to the increasing use of mineral fillers in the production of newsprints were assessed. The results showed that a reduction of more than 18% climate change impact (kg CO2 eq.) was achieved by increasing the fraction of fillers, in the newsprint furnish. Furthermore, the total climate change impact reduction depended on the applied energy mix. Assuming that the production of printing paper was based only on Norwegian energy mix, yielded a reduction of the climate change impact by more than 44% in 2011, compared to the production based on Scandinavian and European energy mix. Additionally, the input and output transport contributed to more than 20% impact in several cases. We thus concluded that the estimated environmental impacts were affected by; i) the furnish composition of a given paper quality, ii) the input and output transport and iii) the use of different primary grid energy sources. [Copyright &y& Elsevier]

The pulp and paper industry faces several challenges linked to climate and environmental impact, resource efficiency, rising energy prices, increased competition for biomass resources, and declining demand for traditional printed paper products. However, these challenges also offer strategic opportunities for the industry to develop into a competitive, resource-efficient, and low-carbon industry in line with a biobased economy. Against this background, this paper aims to analyse current energy strategies in the pulp and paper industry in Sweden. Specifically, the paper analyses how companies combine continuous process efficiency to reduce energy costs with activities that could be developed into new energy-related products to increase revenue. Most of the analysed companies work to various degrees with both these strategies, employing methods that include improving energy efficiency, energy security, and energy conversion, as well as developing a wide range of biobased energy products. However, our study indicates that there is an untapped potential associated with energy product development, and we conclude that energy efficiency measures can free up resources, enabling the development of new energy products. Finally, several potential managerial outcomes and implications are outlined. • The paper analyses the energy strategies in the pulp and paper industry in Sweden. • Energy strategies focus both to improve energy efficiency and develop new energy-products. • The companies' energy strategies combined exploitation and exploration. • A number of managerial implications are presented. [ABSTRACT FROM AUTHOR]

Water removal during paper manufacturing is of primary importance to production rate and cost efficiency for the pulp and paper industry. It is crucial to develop methods to reduce energy consumption by increasing the percent solids in the paper web entering the dryers from the presses. This research aimed to develop a fundamental understanding of the effect of bio-chemo-mechanical pretreatments on a bleached softwood fiber matrix and evaluate the impact on the percent solids of the paper web after pressing. Experiments included enzymatic, refining, and cationic polymer pretreatments on the bleached softwood pulps, followed by laboratory papermaking and determining the equilibrium moisture content (EMC) after pressing and the pulp and paper properties. The combined effect of mild refining, controlled enzymatic pretreatments, and cationic strength aids proved to enhance the water removal during wet pressing (up to 35 % reduction) and increase paper strength (up to 60 % increase). The results of increased solids after pressing were used to calculate the potential reduction in drying energy during paper manufacturing. Energy savings of around 10 % for paper drying could be achieved through fiber matrix modification by bio-chemo-mechanical pretreatment. Enzymatic pretreatments have previously been conventionally applied before refining as an energy-saving method. However, this research shows that synergistic actions of enzymes added after refining modify the fibers and create the optimal conditions for enhancement in drainage, press dewatering, and paper properties. [Display omitted] • Enzyme-assisted fiber modifications improve press dewatering and paper strength. • Enzyme blends can enhance fiber cell wall flexibility and fibrillation. • Synergistically, enzymes increased ∼35% press dewatering and ∼60% tensile strength. • Enzymes, mild refining, and cationic biopolymers enhance paper process efficiency. • This research introduces alternative methods for decarbonizing the paper industry. [ABSTRACT FROM AUTHOR]

To reduce energy use and achieve a low carbon production in pulp and paper industry (PPI), it is essential to improve energy efficiency in pulp and paper production. In this study, the energy savings from the PPI were estimated based on a techno-economic analysis by EAGER tool for PPI at the factory level. The structure and implement procedure were introduced initially. Two typical pulp and paper mills from China were determined to estimate the impact of selected energy efficiency technologies (EETs) on energy savings as the cases in the base year. One Factory (A) only produced paper products (i.e. corrugated paper and Kraft linerboard) while the other Factory (B) also produced market pulp besides sack paper. In totally 22 selected EETs were applied to assess their saving potential in Factory A, and 29 measures were applied in Factory B. The results show that 2290 TJ and 1179 TJ of final energy could be saved annually in Factory A and B, corresponding to reduction of 29.4% and 13.6% total energy consumption respectively for the case factories. The CO 2 reduction potential was 32.3% for Factory A compared with that of 16.6% in Factory B. It suggests that the pulp and paper mills should encouraged to use this method estimating energy saving potential, and improve their energy efficiency with suggested measures in order to reduce energy consumption and related carbon emissions further in the coming years. • Energy savings of pulp and paper production were estimated at the factory level. • A techno-economic evaluation tool was applied to access the energy savings and carbon emission reductions. • Two typical pulp and paper factories from China were investigated to estimate their energy savings in the base year. • It is useful to assess energy savings and select feasible EETs in achieving energy saving and emission reduction targets. [ABSTRACT FROM AUTHOR]

Abstract The annual market demand for disposable baby diapers exceeds 20 billion units (690 kt) in the European Union (EU). Almost 40,000 disposable diapers are used every minute, producing 1.3 t/min (dry weight) of waste. Based on the estimates in this work, this requires 90.3 PJ of primary energy and emits 2.7 Mt CO 2 eq. annually. In an attempt to reduce resource, waste and environmental impacts associated with diapers, this paper focuses on novel design and manufacture of disposable baby diapers. This involves using optimised absorbent core and novel bonding technologies to replace conventional gluing of diaper materials. Life cycle assessment has been performed to compare the environmental performance of these new diapers, here termed "glueless", with standard designs. The annual resource consumption and environmental impacts of glueless diapers have been estimated at different production levels: a single production platform, an industrial plant, a country (Italy) and the EU, taking into account different production volumes, electricity mixes and waste management options. Different market penetration scenarios have been considered to determine potential environmental implications at the EU level by 2020. The results reveal that glueless diapers reduce the consumption of raw materials by 23% (9.2 g/diaper), primary energy demand by 25% (752 kJ/diaper) and global warming potential by 10% (10.4 g CO 2 eq./diaper) compared to the standard diapers. They also have more than 50% lower eutrophication, ozone depletion and human and eco-toxicity. Up to 16 PJ primary energy and 191,000 t CO 2 eq. would be saved annually in the EU by using glueless diapers. The cumulative savings would amount to 47 PJ and 566,000 t CO 2 eq. by 2020. The annual consumption of raw materials at the EU level would be reduced by 196,000 t with cumulative savings of up to 584,000 t by 2020, also reducing the equivalent amount of waste from the disposal of diapers. Consequently, glueless diapers can contribute to meeting the energy, climate and resource efficiency goals specified in the EU 2020 strategy. Graphical abstract Image 1 Highlights • Novel design and manufacture of "glueless" disposable baby diapers is considered. • Glueless diapers save 23% of materials and 25% of energy relative to standard type. • Most life cycle impacts are reduced by >50% and global warming potential by 10%. • Up to 584,000 t of waste and 566,000 t of CO 2 eq. can be saved by 2020. • Glueless diapers can help meet the EU energy, resource and climate change targets. [ABSTRACT FROM AUTHOR]

As the path of industrial eco-efficiency (IEE) needs to be re-examined from a multi-dimensional perspective, this research opens the internal "black box" of China's industrial eco-economic system driven by sustainable development goals (SDGs) and decomposes IEE into industrial production and sustainable development stages. It further divides the industrial production stage into two parallel subsystems of water use efficiency (WUE) and energy efficiency (EE) and derives SDG6 efficiency (SDG 6 E) and SDG7 efficiency (SDG 7 E) in the sustainable development stage respectively. The paper proposes a meta two-stage parallel entropy dynamic DDF-DEA model to re-measure IEE of 30 provinces in China from 2015 to 2021, discusses the relationship between overall efficiency and stage efficiency, and by using the Tobit model explores various types of influencing factors by subregion. The results show that the modified DDF-DEA model can explore China's IEE more accurately under SDGs. China's IEE is more stable from 2015 to 2021, with the efficiency value always fluctuating between 0.59 and 0.64, the overall level is low, and there is more room for improvement. There are significant inter-provincial differences in IEE and efficiency inertia. In more than 75% of the provinces SDG 7 E constrains IEE improvement, while the dynamic evolution of IEE and its subsystem efficiency varies across regions. Environmental regulation is a common factor affecting IEE across the country and in the east, central, and west regions, whereas the level of economic development, openness to the outside world, and urbanization rate are differential factors affecting IEE across the country and in the three major regions. This study offers new perspectives for exploring the path of IEE enhancement and providing empirical references for the collaborative construction of industrial ecological civilization. [Display omitted] [ABSTRACT FROM AUTHOR]

World Cities contribute to a massive amount of carbon emissions. About 80% of the global greenhouse gasses are emitted from these cities. The sustainable practices should be adopted in built environment for these cities. As an example, a residential neighbourhoods in arid climate has been discussed as a case study in practice in this paper. It has been developed to implement the sustainable strategies and concepts. It demonstrates a mixed-use community which integrates the sustainability dimensions to improve the quality toward sustainable living in a small community (about 4000 persons), allocated in Dubai land area. This paper aims to highlight the sustainable practices in the arid zones and to give an overview about the performance of the clean energy and renewable in these areas. The studied development has been selected to evaluate such techniques and strategies in the gulf region (Dubai). Various environmental categories such as; on energy, water, mobility, energy consumption of the buildings and infrastructure, urban green spaces, solid waste management and urban farming, have been appraised in this study. It has been noticed that the urban design proposed reduces its potable water consumption by 40% and for energy demands by 57% compared to conventional households. The solar production can cover around 38% of the energy consumption on average. Many challenges face the sustainability movement in the region, especially, the affordability and feasibility in such harsh climate zones areas. This manuscript opens new perspectives about the prioritization that should be considered for adopting the sustainable strategies in arid climate. Image 1 [ABSTRACT FROM AUTHOR]

Abstract Railways are a rather efficient transport mean, and yet there is increasing interest in reducing their energy consumption and making them more sustainable in the current context of climate change. Many studies try to model, analyse and optimise the energy consumed by railways, and there is a wide diversity of methods, techniques and approaches regarding how to formulate and solve this problem. This paper aims to provide insight into this topic by reviewing up to 52 papers related to railways energy consumption. Two main areas are analysed: modelling techniques used to simulate train(s) movement and energy consumption, and optimisation methods used to achieve more efficient train circulations in railway networks. The most used methods in each case are briefly described and the main trends found are analysed. Furthermore, a statistical study has been carried out to recognise relationships between methods and optimisation variables. It was found that deterministic models based on the Davis equation are by far (85% of the papers reviewed) the most common in terms of modelling. As for optimisation, meta-heuristic methods are the preferred choice (57.8%), particularly Genetic Algorithms. Highlights • Modelling and optimisation methods for railways energy efficiency are reviewed. • Modelling methods provide reliable simulations of the trains' energy consumption. • Optimisation methods help obtaining the most efficient solutions for train traffic. • Most used modelling methods are deterministic, based on Davis equation. • Most used optimisation methods are meta-heuristics, mainly genetic algorithms. [ABSTRACT FROM AUTHOR]

Abstract Water pumping systems are widely used in industrial and civil applications. During their operational life, they consume energy and materials (mainly for installation and replacement of components). The aim of this paper is to optimize the pump operations in order to save energy and enlarge the operational life of the pumps and their components. This paper addresses the multi-period (e.g. 24-hours time horizon) optimization of pumping systems. To this end, we have developed a simulation-based optimization approach including novel relevant technical features of a generic but realistic pumping system, namely cavitation and overflow. The proposed multi-period optimization differs further from the classic static optimization (i.e. at the design stage), proposing a new dynamic approach in which pump activation is steered dynamically for an optimal management of the variability of water inflow. Furthermore, the problem includes constraints on the number of pump activations allowed to reduce material strain. The performances of different meta-heuristic optimization algorithms (e.g. genetic algorithm, simulated annealing and particle swarm optimization) for solving the problem are compared. The numerical results show that energy savings are possible with the dynamic approach and that particle swarm optimization and simulated annealing algorithms provide the most suitable solutions for this problem. Highlights • Three algorithms are compared to minimize energy pump consumption. • The pump model includes energy, cavitation, overow and activation frequency. • Static and dynamic optimizations are investigated. • The dynamic optimization can reduce the energy consumption by 6.5%. [ABSTRACT FROM AUTHOR]

Abstract Energy efficiency improvement is usually regarded as an effective way to decrease energy consumption and to fight climate change, but it also booms energy consumption through rebound effects. But the improvement of energy efficiency also has rebound effects, which increases energy consumption and emission. So this paper arms to capture the rebound effects of efficiency improvement by considering zero-cost breakthrough of energy efficiency and price jump of energy purchase. First, energy efficiency improvement, measured by zero-cost breakthrough of energy efficiency, stimulates energy consumption, but it may reduce the total emission. Second, both the direct and indirect rebound effects of energy efficiency improvement on energy consumption and environment are captured. Interestingly, jumping energy price decreases both the direct and indirect rebound effect. Finally, the result of the paper shows that restriction of individuals' entry or competition restriction moderates the rebound effects of energy efficiency improvement. Highlights • Effect of competition on energy efficiency rebound effects is developed in theory. • Rebound effects of energy efficiency are captured under zero-cost breakthrough. • Moderate monopoly is proofed to be helpful for reducing energy efficiency rebound effects. • Improvement of energy efficiency has both direct and indirect rebound effects. • Energy price jump has offset effects on rebound effects of efficiency promotion. [ABSTRACT FROM AUTHOR]

Abstract In the context of built environment, buildings are amongst the principal generators of environmental externalities. Life Cycle Assessment (LCAs) of energy efficiency and environmental performance of buildings are deemed critical to address sustainable development issues. This paper aims to investigate LCA as a tool to support the design of buildings with two objectives in mind. Firstly, it determines the role of LCA in the evaluation of energy efficiency and environmental performance of buildings. Secondly, it elaborates LCA of these constructions through the lens of international standards. The methodological approach of the study leads to development of a whole building life cycle formula that sums up the contributions from a set of LCAs. By doing so, the paper highlights the necessity of LCA applications in buildings, and the need for minimisation of resource and energy consumption, and environmental impact. The study helps in better understanding the way LCA supports the search for and identification of innovation pathways in buildings. This paper contributes to the efforts in providing theoretical expansions in LCA of buildings and stimulates the creation of technical standards for the residential building construction sector. Graphical abstract Image Highlights • The study overviewed Life Cycle Assessments (LCAs) in residential buildings. • The study discussed stages and methodological aspects related to LCA elaborations. • LCA can have huge applications for quality and sustainability of buildings. • The whole building LCA was formulated as the sum of a set of partial LCAs. • LCA in buildings minimises resource and energy use and related environmental impact. [ABSTRACT FROM AUTHOR]

Pressure servo control plays a crucial role in the majority of industrial applications that use compressed air as their power source. How to reduce the energy consumption of the pneumatic system while ensuring the high accuracy of pressure control remains a key problem to be solved. This paper proposes a Gaussian Process (GP) 1 model predictive controller (MPC) applied to a pressure servo control system based on high-speed on-off valves. The smallest quantity of collected data is used to create the GP model. The entire model, which includes some predictive data, is produced once the generated model has been optimized. The GP model is combined with the MPC to perform comparative experiments using an industrial controller with a Field Programmable Gate Array (FPGA). The system responds quickly and with little tracking error in steady-state response studies as well as dynamic response experiments. The GP-MPC achieves the best outcomes in the dynamic comparison tests. The root mean square error (RMSE) is just 2.42 kPa, and the overshoot is less than 59.9% of the Proportional-Integral-Derivative (PID) controller and 68.5% of the sliding mode controller (SMC). Although the compressed air consumption of GP-MPC is basically the same as that of PID, it is significantly better than SMC, with a total saving of about 70.2%. All the experiments prove that the controller proposed in this paper can effectively improve the energy efficiency and tracking accuracy of the pressure servo control system. [Display omitted] • A Gaussian process model for the high-speed on-off valve is developed which is able to predict uncollected data. • A model predictive controller is established by combining the Gaussian process model with rolling optimization method. • The pressure tracking and energy-saving performance are intended to be improved by using the objective function. [ABSTRACT FROM AUTHOR]

The new roadmap of the European Union (EU), the European Green Deal, aims at tackling climate adaptation, energy, biodiversity, and pollution challenges. To contribute to such aim, the latest EU Renewable Energy Directive defines for the first time renewable energy communities. Among them, Photovoltaic-Green roof Energy Communities (PGECs) emerge as a potential option in urban areas. This paper investigates whether and under which conditions PGECs are capable to meet the objectives of the European Green Deal in an economically convenient manner. Since some conditions are context-specific, this research is showcased using a case study (Luxembourg). First, European legislation was reviewed to determine the suitable legal model for PGECs. Second, a systematic literature review helped identifying lifecycle costs and benefits of photovoltaic-green roofs and their value ranges. Third, a model for probabilistic social and private cost-benefit analyses was developed and tailored to Luxembourg. Lastly, Scenario Discovery was used to identify the ranges of input values leading to desirable net present values. Results show that PGECs can contribute to achieving multiple objectives of the European Green Deal in an economically convenient manner. From the societal perspective, PGECs are found to be economically convenient for any cost, benefit, and discount rate in the case study. From the private perspective, PGECs remain convenient in 62% of the scenarios, with green roofs' installation cost and electricity generation benefit playing pivotal roles. This paper presents a rare combination of probabilistic cost-benefit analyses and scenario discovery, It supports policymakers designing incentive schemes for PGECs, and can be replicated in other countries. [Display omitted] • Review of European legal models for Photovoltaic-Green Roof Energy Communities─PGECs. • The European Renewable Energy Community is the most suitable legal model for PGECs. • Qualitative and quantitative costs-benefit analysis of photovoltaic-green roofs. • PGECs prove economically convenient from private and social cost-benefit approaches. [ABSTRACT FROM AUTHOR]

The startup performance is crucial to the high-efficient operation of the sustainable power generation system. Current literature usually focuses on catalysts and startup strategy to improve startup performance of the proton exchange membrane fuel cell, which ignores the gas foil bearings-rotor system that directly affects startup response. Therefore, in this paper, the effects of bump foil structure, coating, and nominal clearance on the startup response of the bearings-rotor system are first investigated experimentally. Multi-objectives optimization mathematical model considering simultaneously lower power consumption, takeoff speed, and vibration is presented based on grey relational analysis. The optimal bearings-rotor system with radial trisection bump foil, coating MoS 2 , and nominal clearance of 50 μm is identified. Compared to average values, the power consumption of the optimal system is diminished by 27.2% while the takeoff speed and nonlinear vibration are reduced by 16.2% and 47.3%, respectively. These findings can be used to improve energy efficiency and startup performance for fuel cells. The systematic methodology proposed in this study can be extended to other investigations about the startup. • Bump foil type, coating, and nominal clearance are first considered in PEMFCs. • Multi-objective optimization mathematical model is presented. • Optimal gas foil bearings-rotor system is proposed and verified. • Startup performance of the proposed system is improved. • Power consumption of the proposed system is diminished by 27.2%. [ABSTRACT FROM AUTHOR]

Motor systems are ubiquitous throughout the industrial sector, particularly in fluids applications. It is well known that the efficiency of these operations can be greatly enhanced using variable frequency drive (VFD) controls, but adoption of the technology is far from universal. The goal of this paper is to introduce engineering, economic, and environmental analyses to demonstrate benefits to both individual facilities and the state at large. Individual case studies are presented to describe the variety of opportunities for VFD-enhanced motor control; however, this project seeks to describe the combined impact of VFD implementation at a new scale. Data sourced from a U.S. Department of Energy program is used to perform economic and environmental input output analysis to calculate broad impacts of individual audits and recommendations. Results indicate that widespread implementation of VFD controls on motor systems in the industrial sector will introduce significant economic and environmental benefits. One of the scenarios showed a potential reduction of over 4.7 million tonnes of carbon dioxide from regional manufacturing sector as well as a cascading contribution to the regional economy totaling nearly $1 billion. The results are presented as a demonstration of the magnitude of impact that improving control of industrial motor systems can have, as a guide to industry leaders and policymakers about the value of such investments. [Display omitted] • Variable frequency drive (VFD) modifications to industrial motors are described analytically. • Individual micro-scale carbon and cost savings are combined for input-output analysis. • Leveraging VFD control as a universal practice would result in nearly 5 million avoided tonnes of CO 2. • Similarly, economic benefits across the state of Ohio would total more than $1 billion. [ABSTRACT FROM AUTHOR]

Since sustainable scheduling is arousing increasing attention from many manufacturing enterprises and energy consumption is a core problem regarding sustainability, the purpose of this paper is to develop an energy-efficient scheduling method to fulfill material delivery tasks in mixed-model assembly lines. In this research, the objective of minimizing the energy consumption is jointly integrated with the operational criterions when executing material delivery tasks. Owing to the NP-hard nature of the considered problem, a Taboo enhanced Particle Swarm Optimization (TEPSO) algorithm is developed to solve the multi-objective problem. Several improving strategies are applied to enhance the performance of the proposed TEPSO in order to obtain a stronger local search capability and faster search speed. The performance of the proposed TEPSO algorithm is evaluated by comparing with two other high-performing multi-objective optimization methods. Computational experiments are conducted in order to test and verify the effectiveness and efficiency of the proposed TEPSO algorithm. The achievements reported in this paper might be inspiring for further studies on energy-efficient production scheduling. [ABSTRACT FROM AUTHOR]

As one of the most widely used power sources in the engineering field, compressed air is especially common in industrial applications. In a traditional pneumatic circuit, a three-position five-way valve is used to control the air inlet and exhaust with a single pressure, which has low efficiency. This paper proposed a novel bridge-type circuit with variable pressure control using four on-off valves to improve the energy efficiency of compressed air for pneumatic actuators. The key idea of the method was to use air expansion energy to do work. Reducing the volume of consumed air was the goal, and a numerical method was presented to calculate the optimal on-off time sequence of the four valves using nonlinear dynamic optimization. The sequence was obtained based on the combination of a finite element polynomial configuration method and a reduced space sequential quadratic programming algorithm. Then, experimental validation was conducted to illustrate the energy efficiency, including pneumatic cylinder motion test under different conditions. Compared with the traditional circuit, the experimental results show that the bridge-type circuit put forward by this paper can significantly improve the energy efficiency of pneumatic driving systems by 50–70%. Additionally, the bridge-type circuit allows the piston to move smoothly to the end of the stroke, which can take the place of the function of cushion component and speed control valve of the traditional circuit. [ABSTRACT FROM AUTHOR]

Within the urban water cycle, energy issues have been mostly studied for wastewater treatment plants, ignoring that drinking water treatment plants (DWTPs) also consume a significant quantity of energy. Knowing the real energy consumption of DWTPs is the starting point for any energy-saving initiative. This paper benchmarks the energy efficiency measures of a sample of real DWTPs using the data envelopment analysis methodology. Subsequently, whether these facilities are affected by economies of scale is investigated. This issue is essential for planning new DWTPs that minimize energy consumption. In the second stage of analysis, some structural and managerial variables affecting energy efficiency are explored. The results showed that most of the DWTPs analysed have a suitable size but can greatly improve in terms of saving energy. It was found that the age of the plants and the water company operating them significantly affects its energy efficiency. The approach applied in this paper is of great interest for water regulators and company managers since it enables them to learn from the best practices for reducing energy consumption in DWTPs and contributes to improving the sustainability and efficiency of the urban water cycle. [ABSTRACT FROM AUTHOR]

During its operation, a photovoltaic (PV) panel is exposed to various and in general, stochastic thermal and wind conditions, which have a significant influence on the PV panel operating temperature. The increased PV panel operating temperatures normally have an unfavorable effect on the PV panel performance and lifetime, thus various cooling methods were proposed in order to increase the photovoltaic energy conversion efficiency. A reasonable step before the consideration of a specific cooling strategy is to obtain a PV panel performance analysis with respect to its surroundings (specific geographical micro location) for various operating conditions. This paper presents such a study, which was conducted through an experimentally validated numerical model. Numerous CFD simulations regarding heat and fluid flow around a monocrystalline PV panel coupled with a heat flow simulation inside the PV panel elements were conducted. The aim of the paper was to investigate an effective heat transfer field and the variations in the PV panel temperatures with respect to various wind velocities and heat source conditions. A detailed study regarding pressure, viscous and body (buoyancy) forces as well as their effects on flow separation was also conducted. The study also investigated the changes in the effective heat transfer near the PV panel. The gained results in this study turned out to be useful for the consideration of a specific cooling strategy for PV panels, which can ultimately lead to an increase in PV panel efficiency and lifetime. Additionally, the conducted study could be used to improve the delivered electricity prediction from the PV system at a selected location defined by specific wind velocities and solar insolation distributions. [ABSTRACT FROM AUTHOR]

One-third of global energy demand as well as CO 2 emissions is accounted to industrial processes. In particular, over 30% of total industrial energy consumption is attributed to the iron and steel, cement and refining industry. The aim of the present paper is to review crosscutting technologies and measures adopted to improve energy efficiency in the main Italian industrial sectors regulated by the recent EU legislation on integrated pollution prevention and control (IPPC-IED). In fact, 2010/75/EU Directive on industrial emissions, a general improvement on the entire environmental performance of the industrial installations is pursued by taking into account relevant environmental issues, such as emissions into water, air, soil as well as energy efficiency, waste production, recovering and recycling, restoration of the site upon definitive cessation of activities. Moreover, according to 2010/75/EU Directive, IPPC permits should be based on Best Available Techniques (BAT) aimed to reach an adequate level of environmental protection and should establish all the necessary measures including operating conditions, emission limit values for relevant polluting substances as well as monitoring requirements. Thus, in the present paper an assessment of Best Available Techniques (BAT) related to energy efficiency in the main Italian industrial installations is carried out on the base of the analysis on the IPPC permits released by the Italian Ministry for the Environment, Land and Sea, and made available on its web site. As a result a significant improvement in energy efficiency was assessed. In fact, many process units were upgraded, by major revamping or even by replacing the process completely with one showing better performances. Finally, since energy efficiency is at its best at the beginning of the life cycle of the plant, operators, whenever necessary, periodically monitor and measure the actual energy performance of their own installations for process control and maintenance purposes. [ABSTRACT FROM AUTHOR]

Whether industrial agglomeration can promote an increase in energy efficiency is of great importance to not only China’s energy conservation and emissions reduction plans, but also China’s future sustainable development. This paper uses statistical data from 285 cities, from 2004 to 2013, to analyze the effect of industrial agglomeration on energy efficiency. The spatial autocorrelation tests show that there is significant spatial autocorrelation and spatial heterogeneity in urban energy efficiency. Although dynamic spatial econometric results show that industrial agglomeration can promote an increase in energy efficiency from a country level, there are significant differences at a regional level. In the east, the effect of industrial agglomeration on energy efficiency has a threshold effect, but in central and western areas, industrial agglomeration can promote the increase of energy efficiency, with the positive effect in western areas greater than that in central areas. Finally, based on the research, this paper puts forward concrete suggestions to enhance energy efficiency. [ABSTRACT FROM AUTHOR]

A sustainable hydraulic system is proposed to cool the slurry manure and mitigate the ammonia emissions of livestock buildings, a major source of environmental pollution. In this paper, analytical and numerical methods are used to evaluate the energy efficiency and the mitigation capability of the hydraulic cooling system. Results show that annual primary energy use of only 6.08 kWh per animal can reduce 5.87 kg of ammonia per animal per year. The system is most efficient for manure with less than 12% total solids content. Results also show that the liquid region above the cooling pipes features one-dimensional transient heat transfer formed by unique flow patterns. A simplified analytical model is derived to predict the surface temperature of liquid manure. The analytical solution shows that the manure surface temperature can be reduced by 7.4 and 12 °C after 2 and 5 h, respectively. The temperature reduction results in up to 37.3% decrease in ammonia emissions with only 0.8% of the total energy use in livestock buildings. • An energy efficient cooling system is proposed to reduce emissions from buildings. • Using primary energy of only 6.08 kWh can reduce 5.87 kg NH3 per animal per year. • The cooling system uses only 0.8% of the total energy use in a livestock building. • The cooling system can reduce up to 37.3% NH3 emissions from livestock buildings. • An analytical model is derived to predict the surface temperature of liquid manure. [ABSTRACT FROM AUTHOR]

The Sustainable Development Goal (SDG) that emphasizes sustainable and affordable energy presents a practical pathway to achieve sustainable growth. Moreover, this goal aligns with SDG 13, which focuses on climate action. Nonetheless, it is important to consider factors such as political and financial risk, as they can influence climate action efforts and the renewable energy sources adoption. Hence, this study broadens the conversation surrounding CO 2 emission reduction and the achievement of Sustainable Development Goals (SDGs). It accomplishes this by investigating the interplay between renewable energy, political risk, financial risk, and CO 2 emissions in Finland spanning from 1990/Q1 to 2021/Q4. Notably, this research distinguishes itself through its exploration of these complex connections, employing a wavelet-based quantile methodology. Unlike traditional quantile regression, which can only reveal connections between variables within each quantile, the wavelet-based quantile approach enables the simultaneous capture of correlations across quantiles and periods. The results show that in the long-term and across all quantiles (0.01–0.99), energy efficiency, specifically gas and oil efficiency, lessens CO 2. In addition, low financial and political risks improve ecological quality by lessening CO 2 across all periods and quantiles (0.01–0.99). The paper outcomes serve as a basis for formulating a policy framework aimed at achieving SDG 7 and SDG 13 in Finland. • We explore the impact of energy efficiency and country risk on CO 2 emissions. • The role of renewable energy and economic growth are also analyzed. • The Time series data of the Finland is used from 1990/Q1 to 2020/Q4. • Various wavelet-based quantile correlation is applied. • Renewable energy, oil and gas efficiency decrease CO 2 emissions in each quantile and across periods. [ABSTRACT FROM AUTHOR]

Policies targeting energy efficiency and renewable energy are sometimes viewed as more politically feasible than carbon pricing in pursuit of emission reduction goals. This paper assesses underlying drivers of energy policy development. These factors include economic, social, environmental, and institutional variables. The between estimator for panel data is an appropriate method for our focus on some exogenous variables that vary more across countries than over time. We find that larger oil reserves per capita have a negative relationship with renewable energy policy development. Education and political globalisation have strong positive relationships with both energy-efficiency and renewable-energy policy development. These results suggest that greater participation in global political groups can be an indirect approach toward energy policy development, in cases where direct and immediate policies are hard to implement. OECD countries have higher policy scores by 33 and 25 points in energy efficiency and renewable energy respectively. Blinder-Oaxaca decomposition analysis shows that these higher scores are primarily due to social and political institution predictors rather than economics and physical endowments. • Large-n cross country international sample on continuous policy score measurement. • Political globalisation is positively linked with renewables and energy efficiency policies. • Education is positively linked to energy policy development, especially for efficiency. • Higher OECD countries' policy scores are primarily due to social and political predictors. • Higher incomes are unlikely to lead to automatic improvements in energy policies. [ABSTRACT FROM AUTHOR]

Hot embossing is an efficient technology for the fabrication of glass micro- and nanostructures. However, the long cycle time, high energy consumption, and high nitrogen emissions in traditional hot embossing approach hinders sustainable production of glass micro-optics. Therefore, this paper proposes a novel two-stage gravity-assisted hot embossing process that enables the fabrication of high-quality glass micro-pillar arrays in a rapid, green manner. In this approach, the two-stage gravity loading unit provides accurate force on glass preform through a simple control system, and the tailor-made heating module based on Si 3 N 4 ceramic heaters requires an energy consumption of just 700 kJ per molding cycle. As a result, the proposed approach is featured by low energy consumption and high manufacturing efficiency. In this study, the effects of the embossing temperature, force, and time on the replication accuracy of a K9 glass micro-pillar array were investigated through a series of hot embossing experiments. Afterward, the form accuracy, uniformity of microstructures, and warpage of glass replicas under the optimal process parameters were evaluated separately. Finally, repeated hot embossing experiments were conducted to demonstrate the reproducibility of the hot embossing process. The experimental results show that embossing temperature had the most significant effect on the replication accuracy of glass micro-pillars. By optimizing the process parameters, the embossed glass micro-pillars could achieve transfer ratios of 99.00% and 95.14% in height and diameter, respectively. Moreover, the surface roughness of glass micro-pillars was less than 5 nm, and the warpage amplitude of glass replicas in a 3.9 × 3.9 mm area was smaller than 1 μm. The small discrepancy in geometric features of glass replica in the repeated trails reflects the satisfactory reproducibility of this hot embossing process on the micro and nano scales. The results indicate the strong industrialization potential of the proposed two-stage gravity-assisted hot embossing machine and hot embossing process for fabricating high-quality glass microstructures more cleanly and sustainably. • A novel gravity-assisted rapid high-temperature hot embossing apparatus is developed. • A novel hot embossing process is designed for fabricating high-quality glass micro-pillar arrays in a cleaner manner. • Effects of process parameters on the replication accuracy of glass micro-pillar arrays are evaluated. • Form deviation, uniformity of microstructures as well as warpage of glass replica are analyzed. • The reproducibility in replicating geometric features in the novel hot embossing process is demonstrated. [ABSTRACT FROM AUTHOR]

The improvement of energy efficiency of products is a key pillar of climate and energy strategy in the European Union (EU). The first EU product policies were adopted in the late 1970s, and they have evolved to become a coherent set of implementing measures under framework directives that harmonise and refine the regulatory process. After years of weak implementation, considerable progress in terms of scale and ambition has been achieved in the last decade. In 2020, product mandatory measures covered 50% of the EU total final energy consumption, leading to 46 Mtoe energy savings. This paper describes the available policy instruments to promote energy efficiency and remove the market barriers hindering the penetration of the best performing technologies. It offers a review of the progress made over these last 40 years of EU product policies, describing the Energy Labelling, the Minimum Energy Performance Standards (MEPS), the Ecodesign Directive and the voluntary agreements (EU Ecolabel and Green Public Procurement). Moreover, it highlights the remaining challenges and provides policy recommendations to further exploit the EU potential to save energy from products. • Energy efficiency in products is a key pillar of EU climate and energy strategy. • Despite 40 years of EU product policies, their scale has only improved since 2010. • In 2020, mandatory measures covered 50% of the EU final energy consumption. • By 2030, savings expect to reduce the final consumption by 17%. • Policy orientation to further exploit the energy savings of products is provided. [ABSTRACT FROM AUTHOR]

Energy consumption is a major sustainability focus in the metal cutting industry. As a result, process planning is increasingly concerned with reducing energy consumption in machine tools. The relevant literature has been categorized into two research areas. The first includes energy prediction models, which characterize the relationships between cutting parameters – the main outputs of process planning - and energy consumption. The second involves energy-consumption optimization, which uses the prediction models to find the cutting parameters that minimize energy use. However, previous energy prediction models are limited to predict energy for tool paths coded in a Numerical Control (NC) program. Previous energy optimization methods typically do not use online optimization, which enables fast optimization decision-making for supporting on-demand process planning and real-time machine control. This paper presents a component-based energy-modeling methodology to implement the online optimization needed for real-time control. Models that can predict energy up to the tool path-level at specific machining configurations are called component-models in this paper. These component-models are created using historical data that includes process plans, NC programs, and machine-monitoring data. The online optimization is implemented using a dynamic composition of component-models together with a divide-and-conquer technique. The feasibility and effectiveness of our methodology has been demonstrated in a milling-machine example. [ABSTRACT FROM AUTHOR]

Mexico is an important iron and steel manufacturer; it is the 13th largest steel producer in the world. The Mexican iron and steel industry is first in energy consumption for industrial energy use, representing 14.3% of the total industrial final energy consumption and a similar share of related carbon dioxide emissions. The aim and novelty of this paper is to estimate both the energy intensity and CO 2 intensity of the Mexican iron and steel industry in 2010 based on defined system boundaries and an international comparison methodology and to compare the energy intensity of Mexican with those the US and China based on a literature review. The boundaries consider energy consumption for all coke making, pelletizing, sintering, iron making, steel making, steel casting, hot rolling, cold rolling, and processing, such as galvanizing or coating. They also include energy use for net imported pig iron, direct-reduced iron, pellets, lime, oxygen, ingots, blooms, billets, and slabs. Under these boundary conditions, the Mexican iron and steel industry was shown to be more energy efficient and less carbon intense than those the U.S. and China. The reasons for this efficiency are mainly the large shares of the electric arc furnace route (69.4%) and continuous casting (100%) in production and the large share of natural gas in the fuel mix. This paper highlights the importance of the definition of boundaries and clear methodologies to analyse the iron and steel energy efficiency. [ABSTRACT FROM AUTHOR]

This paper presents an integer linear programming (ILP) model to minimise the total energy-cost of a flake ice production unit in food retail stores. This work is based on a real problem in a Portuguese food retail company, where flake ice in necessary throughout the day in order to maintain fresh fish on the shelves at ideal temperature conditions and humidity levels. The proposed approach aims to provide an energy-efficient scheduling of the production to periods with a lower energy cost, as well as to reduce water consumption, by producing the exact quantities required at the right time, minimising waste. The model was tested on a set of real-world instances from the retail company, and on a set of randomly generated instances. The procedure used to create these instances is presented in the paper. For the sets of tested instances, the results show that the model is strong when compared to the lower bounds provided by the linear programming relaxation of the model. The results from the set of real instances show that it is possible to achieve an energy-efficient scheduling of the production which translates in an average annual cost savings of 34.3% for the stores. [ABSTRACT FROM AUTHOR]

There is a large untapped potential for improved energy efficiency in various sectors of the economy. Governmental industrial energy audit programs subsidizing the companies to conduct an energy audit are the most common policy in trying to overcome the energy efficiency gap. Evaluation studies have been carried out to gain knowledge about the success of a completed energy audit policy program. The evaluations were made in different ways and in addition focused on different performance indicators and used different ways of categorizing data. In this article, a literature review has been made of five evaluation studies from different energy audit programs, where the problems of the present incomparability between programs due to differences are discussed. The policy implication of this paper is that new energy audit policy programs must distinguish a harmonized way of categorizing data, both regarding energy efficiency measures and energy end-use. Further, a proposition for a standard for how to evaluate energy audit policy programs is suggested. Conclusions from this study are that important elements, such as the free-rider effect and harmonized energy end-use data, should be defined and included in evaluation studies. A harmonized standard for evaluating audit programs is not least needed within the EU, where member states are obliged to launch audit programs for large enterprises, and preferably also for small and medium-sized enterprises. This paper serves as an important contribution for the development of such a standard in further research. [ABSTRACT FROM AUTHOR]

With the advent of the era of big data, large-dimensional spatial panel data is gradually used to do empirical research in the macroeconomic field. This paper adopts a Data Envelopment Analysis(DEA) approach to calculate regional energy efficiency based on the perspective of total-factor energy efficiency using statistical data of 30 administrative regions in China. On basis of spatial effects, the paper assesses the convergence of regional energy efficiency in China using large-dimensional spatial panel data model. Our results indicate that (1) There is significant spatial autocorrelation and clear spatial effects in China's regional energy efficiency. Thus, spatial effects should not be ignored when assessing the convergence of regional energy efficiency in China; (2) During the period from 2000 to 2014 China's regional energy efficiency not only exhibits absolute β -convergence but also exhibits conditional β -convergence, the convergence rate is higher than the rate of absolute convergence after controlling for the initial conditions of the level of economic development, foreign direct investment and government influence; (3) The convergence rate of China's regional energy efficiency from 2004 to 2014 is higher than the convergence rate for the period of 2000–2004, which indicates that industry transfer has contributed to improvement in the convergence of regional energy efficiency in China since 2004. [ABSTRACT FROM AUTHOR]

In a multi-pass face milling process, cutting parameters for each pass and the total number of passes dramatically affect the electrical energy consumption and production cost of the final product. In this paper, the electrical energy consumption characteristics of multi-pass face milling are firstly analyzed. Then a multi-objective parameter optimization model for maximizing energy efficiency and minimizing production cost is proposed and solved by the Adaptive Multi-objective Particle Swarm Optimization algorithm. Finally, a case study is carried out to validate the proposed model and search for the trade-off solutions between maximum energy efficiency and minimum production cost. From the results of the case study, significant interaction effects between cutting parameters and number of passes are revealed. Moreover, it also can be found that the traditional multi-pass parameter optimization for minimizing production cost does not necessarily satisfy the maximum energy efficiency criterion. Simultaneously optimizing the cutting parameters of each pass and the total number of passes achieves a trade-off between maximum energy efficiency and minimum production cost. Based on the work presented in this paper, manufacturers can easily improve energy efficiency and reduce production cost in the multi-pass face milling process. [ABSTRACT FROM AUTHOR]

Adoption and improvement of energy efficiency is one of the recommended pathways to tackle the problems of growing energy demand and greenhouse gas emissions. However, studies show that rebound effects from energy efficiency improvements can erode anticipated energy savings. This paper elucidates the rebound effect arising from energy efficiency initiatives in Kenya. The study uses Index Decomposition Analysis to assess the drivers of Kenya's total primary energy supply. The paper then adopts the neoclassical growth model in the empirical analysis of energy and carbon rebound effects at the macro-economic level. Cobb-Douglas production function is further applied using Solow growth model and energy as a factor of production to approximate technological progress. Results of decomposition of energy supply show that energy intensity and affluence are the drivers with the most significant effect on energy supply while population has less critical effect. Average energy and carbon rebound effects show partial rebounds of 15.64% and 31.41%, respectively. These results imply that there is need to accelerate the pace of transitioning to green energy as the ultimate solution to minimizing environmental impacts arising from energy use and tackling climate change. • Carbon and energy rebound effects of energy efficiency initiatives is studied. • Decomposition analysis is used to investigate drivers of energy supply. • Energy intensity and affluence have most significant influence on energy supply. • Average estimates of carbon and energy rebound effects are partial rebound effects. [ABSTRACT FROM AUTHOR]

Excessive energy consumption and carbon dioxide emissions are long lasting issues and need continuous research to improve efficiency evaluation and performance monitoring of economies. The static and dynamic aspects of efficiency need to be dealt with simultaneously to thoroughly analyze the performance of economies. This paper aims at conducting a static and dynamic analysis of energy and CO 2 emissions efficiency of major economies. In this paper, we applied slacks based model of Tone (2001) with the treatment of undesirable output in objective function and constraint assuming free disposability of undesirable output and built a dashboard. The results can be summarized by saying that the larger economies with intensive production strategy, larger secondary industry, and weaker carbon tax laws are more likely to be inefficient. China, India, and Russia have the greatest potential for improvement in both energy efficiency and carbon dioxide emissions efficiency. The suggested dashboard has the ability to dig out the potential for efficiency improvement of countries like the USA, which mostly appear at the efficient frontier with other techniques. Concluding it can be suggested that economies in lower ranks of dashboard need stricter policy measures to cut energy consumption, carbon dioxide emissions and encourage a shift from fossil fuels to other renewable resources of energy. [ABSTRACT FROM AUTHOR]

The cement industry is generally considered responsible for upwards of 5% of anthropogenic greenhouse gas emissions. This is a result of the high energy intensity of the process, significant CO 2 release from the raw materials used, and large global consumption. It is also a high growth sector as emerging economies develop their infrastructure. This paper outlines an investigation into day-to-day performance variation that, if scaled to the global level, represents a potential for improvement of up to 100 Mt CO 2 equivalent per year. Optimising this operational variation is not included in current roadmaps for reduction of cement industry CO 2 emissions, and has the potential to be cost neutral, or even save money for cement producing companies. The paper analyses a case study of a plant in the UK, operating a pre-calciner type kiln commissioned in 1986. Production data was analysed to examine the day-to-day variation in the fuel-derived CO 2 emissions, in order to estimate the potential for operational improvement. Various factors were then analysed to determine what drives this potential improvement, including fuel mix, rate of production, and process airflow. The day-to-day performance of the plant, as measured by the fuel-derived CO 2 emissions per tonne of clinker produced, varied significantly. (Clinker is the material ground and mixed with ∼3% gypsum to produce cement). Improvement of the plant to 10th percentile best observed performance levels would represent a 10% drop in CO 2 emissions and a 7% drop in energy consumption, with associated cost savings. Two mathematical models were used, first to examine the energy balance of the plant and then to predict CO 2 emissions from given input conditions. The largest source of energy consumption was the dissociation energy required to form clinker, however, the variation in this was small. Airflow and fuel type were found to dominate the variation of performance. Optimising the factors affecting performance was predicted to reduce energy consumption by 8.5% and CO 2 emissions by 19.5%. The paper concludes that there exists significant opportunity to reduce the emissions from cement plants by operational means, and that fuel mix and excess air ratio should be the focus of future research. [ABSTRACT FROM AUTHOR]

Pinch Analysis (PA) and Exergy Analysis have been used, either independently or in combination, for energy integration of process plants. This paper discusses a methodology to apply PA and Exergy Analysis during design of a new process plant to make it energy efficient, using Diesel Hydrotreating Unit (DHT) as an example. PA has been used to estimate the Minimum Energy Requirement (MER), to select utilities and to design the optimal Heat Exchanger Network (HEN). Exergy Analysis is then performed to pinpoint the sources of energy inefficiency in the whole plant and suggest improvements. The application of these two techniques has helped in energy integration of the plant during the design phase itself. Two common layouts of diesel hydrotreating unit—the 'hot separator layout' and the 'cold separator layout'—have been studied. The minimum Total Annualized Cost (TAC) is ∼7.6 M€/y and ∼10 M€/y for the hot separator layout and the cold separator layout respectively. Exergy destroyed is 27.15 MW (7.9% of exergy input) and 50.18 MW (6.7% of exergy input) respectively for the hot separator layout and the cold separator layout. Exergy Analysis reveals that the energy efficiency can be improved for air coolers, fired heaters and letdown valves. • Pinch and exergy analysis carried out on design of new DHT. • HEN with minimum TAC obtained by pinch analysis. • Sources of energy inefficiency identified by exergy analysis. • Modifications for improving energy efficiency provided. • Equipment modifications resulted in higher exergetic efficiency. [ABSTRACT FROM AUTHOR]

Modern manufacturing enterprises are consuming a considerable amount of energy every year. Improving energy efficiency will not only benefit the enterprises economically, but also help the world to overcome various problems such as energy crisis and air pollution. To achieve this, an accurate energy consumption model is essential. The main objective of this paper is to develop an improved cutting power-based energy consumption model for general end milling process. The proposed model consists of an idle part due to auxiliary components and spindle rotation, and an additional part due to cutting workpiece materials. The first part is modelled as a function of spindle rotation speed, and the other part is considered proportional to the cutting power. Experiments under various milling conditions have demonstrated the effectiveness and efficacy of the proposed model. Comparative studies show that the proposed model is more accurate than other models. Although calibrated from slotting experiments when cutting aluminium alloy, the proposed model is applicable for general milling process. Partial-immersion milling experiments show that the prediction error of the proposed model is as low as 1.74%. When workpiece material changes to titanium alloy, its performance remains decent, with low prediction error of 2.81%. This reveals its capability to provide reliable estimation for different workpiece materials. As such, it could help avoid tedious model calibration, thus saving time, material, and energy. Finally, the energy efficiency of general end milling process is investigated through numerical experiments with the proposed model. By revealing the relationship between energy consumption and various cutting parameters, the proposed model could serve as an excellent platform towards energy-efficient manufacturing/cleaner production. • A new energy consumption model (ECM) for general end milling is proposed. • The ECM's accuracy and reliability is validated by general milling experiments. • The ECM significantly improves the prediction accuracy than other major models. • Energy efficiency can be analyzed with the ECM via numerical experiment. • The ECM contributes to cleaner production by saving time, material, and energy. [ABSTRACT FROM AUTHOR]

Environmental energy is being studied actively around the world due to the effects of climate change, global warming, and energy policies. Energy policies are being reinforced to reduce building energy consumption. Therefore, environmental-friendly and sustainable building materials have been used to reduce energy consumption. The cross-laminated timber (CLT) wall is an environmental-friendly material that stacks layers at right angles, and bonds them together to form large solid panels. However, there is no standard for CLT structure walls in Korea. This study focuses on analyzing the hygrothermal properties of the CLT wall by showing the water content of the CLT wall, mold growth risk of CLT by WUFI simulation, and energy load by DesignBuilder using the climatic conditions of Seoul, Korea. CLT walls Ext_EPS, Ext_FG, and Ext_EPSFG based on an external insulation system, and walls Int_EPS, Int_FG, and Int_EPSFG based on an internal insulation system, were prepared for simulation analysis. The total water content (TWC) of Wall Ext_EPSFG was measured to be 8.67 kg/m2, which was the lowest TWC. This indicates that the TWC of the external insulation system wall is lower than that of the internal insulation system wall. Furthermore, the water content (WC) of structure based on the external insulation system is lower than that based on the internal insulation system. This indicates that the WC of Wall Ext_FG, measured to be a maximum 8.69% of WC, is lower than Wall Int_EPS, measured to be a maximum 10.45% of WC. According to the risk of mold growth, this indicates that all of the CLT wall layers have low mould growth risk, and the maximum mould index of walls Ext_FG and Int_EPSFG was measured to be 0.019. As a result of the hygrothermal analysis in this paper, CLT walls based on an external insulation system are more suitable than the internal insulation system. Therefore, this study analyzed the energy consumption of CLT walls based on the external insulation system, which was found to be lower than the energy consumption of the internal insulation system walls. • Cross-Laminated Timber Wall (CLT) is an environmental-friendly building material. • Water Contents (WC) and Mold growth of CLT walls are analyzed using simulation program. • WC of external Fiberglass insulation CLT wall measured to be a maximum 8.69%. • The mold index of external Fiberglass insulation CLT wall was measured to be 0.019 • Ext_EPSFG CLT wall was measured to show 3.53% energy savings. [ABSTRACT FROM AUTHOR]

The role of smart technologies can become very important and useful to solve the main population issues nowadays and provide foundations for a sustainable future. A smart approach is an opportunity for knowledge integration, necessary to solve crucial problems of contemporary societies. Today, the main challenge is to reduce the effects of global warming and ensure a balanced economic development of society. The close collaboration of all involved engineering professions is mandatory to achieve interdisciplinary synergies and can bridge challenging engineering tasks. Intense research efforts should be directed towards balanced resource utilization, efficient energy conversion technologies, integration of renewable energy systems, effective approaches to enable circular economy framework, effective process integration as well as other issues important to the population. This review editorial is primarily focused on the contributions presented at the 3rd International Conference on Smart and Sustainable Technologies held in Split, Croatia, in 2018 (SpliTech2018). The SpliTech2018 conference was a multidisciplinary event with research topics related to the main conference tracks, i.e. Smart City/Environment, Energy, Engineering Modelling and e-Health. The strategic focus of the conference was to help solve crucial issues of our times, mainly related to the sustainability and smart utilisation of limited and valuable resources. This contribution brings new ideas and discusses present issues as well as challenges that should lead towards a sustainable future based on the application of the smart technologies. The herein addressed papers bring together latest research progress into four main topic areas: (i) Green Buildings, Energy Use and Consumption, (ii) Solar Energy Utilisation, (iii) Efficiency and Waste Elimination, (iv) Smart Cities and Internet of Things. The main results of this introduction review article include a discussion of different concepts and technologies that bring further development on a broad range of topics focused on efficiency improvement, smart and sustainable resource management, cleaner production concepts and on the discussion of the various actions which would lead towards a sustainable future. [ABSTRACT FROM AUTHOR]

This paper investigates the effect of the implementation of smart city policy (SCP) on energy efficiency (EE) in China. For this purpose, we have developed a non-convex metafrontier data envelopment analysis (DEA) approach to measure EE, and empirically examine the impacts of SCP on China's EE using Difference-in-Differences (DID) analysis, using a dataset of 251 cities between 2003 and 2016. Results show that there exists significant regional heterogeneity across cities, with the SCP exerting a significant positive effect on EE, indicating that the SCP can effectively improve EE during the study period. These findings are robust to different sub-sample, energy efficiency alternative measures, estimation strategies, and Baidu Search Index. Based on empirical results, the implications of SCP are outlined. • Energy efficiency measures of 251 Chinese prefectural-level cities are estimated. • Eastern region performs the best, followed by the central and western regions. • The effects of smart city policy on energy efficiency is investigated using DID method. • The smart city policy can effectively improve energy efficiency during the study period. • Empirical results are robust to different sub-sample, energy efficiency alternative measures, etc. [ABSTRACT FROM AUTHOR]

This paper estimates the linkages among total Sulphur dioxide (SO 2) emissions, total GDP and energy efficiency using China's provincial panel data from 2002 to 2015. We investigate total emissions rather than per capita emissions or ambient concentrations since it is total emissions that the environment cares about. Energy efficiency is estimated using stochastic frontier analysis and decomposed into both persistent and transient efficiency. We then investigate the long-run dynamics among SO 2 emissions, economic growth, and energy efficiency by employing the panel-based error correction model and taking the effects of cyclical variations into account. Our analysis shows that GDP has a positive impact on total SO 2 emissions in the short run and gains in energy efficiency have a significant negative effect on emissions in the long run. By controlling the effects of the business cycle, the effects of GDP on emissions remain positive in both the short and long run. The cross-sectional analysis provides similar insights. We argue that economic growth itself is an emission generator. Therefore, the government needs to establish a long-run strategy to curb emissions by improving energy efficiency. Image 1029 • We estimate the linkages among sulphur dioxide emissions, GDP and energy efficiency. • Energy efficiency is estimated by SFA and decomposed into persistent and transient efficiency. • We employ the panel-based error correction model with cyclical variations and structural break. • GDP has a positive impact on emissions in both the short and long run. • Gains in energy efficiency affects emissions negatively in the long run. [ABSTRACT FROM AUTHOR]

This paper presents the application of the Discrete Event Simulation (DES) in an industrial plant to analyze the behavior of the consumption and generation of electrical energy in conjunction with other variables of the process. In other words, the process modeling was conducted considering the energy consumption in equipment as well as the local photovoltaic (PV) energy generation. A medium-sized plant was the reference base used herein, and the main variables considered were the time of supply of tanks and processing of raw material, active power of equipment and energy tariffs. A simulation model with resolution in seconds was designed, enabling the simulation of consumption curves of each equipment of a given part of the production process. The equipment of variable active demand was modeled by a mathematical regression method, and the others were assumed with constant power. The same model was altered to unit in minutes for simulating the monthly electricity consumption, so as to obtain financial results. The contractual rules for electricity supply were included, and the use of a diesel-powered generator was taken into account. The application of a freeware was employed as a low cost alternative for small and medium-sized companies, even though the lack of graphic resources has increased the complexity of the system modeling process. The model with resolution in seconds proved to be efficient to simulate the consumption profile of a specific equipment that alters the power in a short-time period, such as the pumps. The model, on the other hand, in minutes allowed a more effective analysis in terms of finance, enabling the verification of alternative scenarios throughout a month. The monthly cost reduction perceived by considering self-generation in this model was about 36%. Detailed diagram of the main elements of modeling of a manufacturing process of an industry concentrating on the consumption and generation of electric energy. Image 1 • The electricity consumption in an industrial process can be approached in a simulation model. • PV energy can be simulated together with variables of industrial processes. • The discrete event simulation can be used in industrial processes to optimize the electricity management. [ABSTRACT FROM AUTHOR]

Abstract The inspection of transmission line using suspended based robots has drawn great attention from many utility companies. Such an emerging smart technology has the advantages of energy efficiency, cost effectiveness, safety, non-service interruption, and the potential of substituting for the traditional inspection method using linemen with the help of helicopter. In this paper, we propose a routing algorithm to identify locations where the ground control station needs to be deployed when using suspended robot in transmission line inspection. The motion and location between the suspended robot and the ground team are coordinated. The bidirectional data transmission between two sides can be guaranteed so that the live signal can be received and processed, robot motion can be controlled, large size obstacles can be appropriately cleared, and health condition of the transmission line can be captured. A case study based on a segment of the transmission line in the state of Missouri of the United States is implemented to validate the effectiveness of the proposed routing algorithm. Results of the case study illustrate that the performance from both economic and environmental aspects can be significantly improved compared to the traditional inspection mode employing helicopter and linemen as well as an ad-hoc routing algorithm currently used by some utility companies to guide the suspended robot in transmission line inspection. Specifically, compared to the ad-hoc routing algorithm and helicopter with photoelectric stabilized pod, the proposed algorithm can reduce the unit cost by 7.55% and 8.04%; and cut the unit emission by 21% and 98%, respectively. [ABSTRACT FROM AUTHOR]

Abstract Addressing housing-related energy consumption and emissions is a challenge in many countries. Low-energy housing, e.g. whole house retrofits and zero-energy new houses, is still rare in the United Kingdom, yet very much required to reduce emissions. This paper contributes to research on low-energy housing by adding new empirical material through analysing how specific drivers linked to knowledge, public policy and intermediary actors can influence successful projects. Based on in-depth case study research of both existing and new built low-energy housing projects in Brighton, United Kingdom (UK), we show that in addition to motivations to improve existing housing conditions, knowledge and available skills of householders and project participants, and both local and national policies, drive such projects. We also find that intermediaries inspire projects, connect different actors and facilitate learning between projects. Intermediaries are important for advancing projects through local actors and knowledge-networks, especially at a time when national policy support for low-energy housing remains limited and a wider transition to low-energy housing is not complete. Highlights • Housing related energy consumption and emissions need urgent reductions. • Dedicated individuals can drive low-energy housing projects. • National policy is needed to support projects, aided by focused local-authority action. • Intermediaries can help by translating policies and facilitating learning. • Highlight low-energy housing as well-designed and comfortable to create demand. [ABSTRACT FROM AUTHOR]

Abstract Electrical discharge machining is a significant non-traditional technique, widely used in the precise manufacturing field. However, the electrical discharge machining process possesses plenty of energy consumption and hazardous exhaust emissions. Since a sustainable machining technique, external magnetic field assisted, could dramatically develop sustainable machining performance of electrical discharge machining process, this paper presents a comparative study energy efficiency and environmental impact in magnetic field assisted electrical discharge machining and conventional electrical discharge machining. A novel thermo-physical model was proposed to calculate energy distribution under the single/continuous discharge, which was verified by a series of corresponding experiments. Then, based on simulation and experimental methods, a comparative study on the magnetic field assisted electrical discharge machining and conventional electrical discharge machining was conducted to analyze the discharge energy flowing and temperature distribution of workpiece, electrode tool and debris. Moreover, the effects of external magnetic field on the machining performance, environmental impacts and energy efficiency were presented. Eventually, it can be found out that the effect of magnetic field contributes to increasing energy utilization efficiency by 15.2%, material erosion efficiency by 22.6%, and material removal rate by 21.9%. To balance energy efficiency and surface roughness (Ra), the optimal parameter combination is obtained as below: magnetic field intensity: 0.2T, discharge current: 7–9A, and pulse duration: 300s. Highlights • Magnetic field assisted EDM improve energy efficiency and environmental impact. • A thermo-physical model is proposed to calculate energy distribution of MF-EDM process. • Sustainable machining performance of EDM and MF-EDM are comparatively investigated. • The optimal parameter is: magnetic field intensity: 0.2T, current: 7∼9A, and pulse duration: 300μs. [ABSTRACT FROM AUTHOR]