Search

The pulp and paper industry, which provides cellulose pulp and paper, bio-based energy and chemicals, is one of the largest energy consumers, greenhouse gases (GHG) and pollutant emitters among manufacturing industries. Although the environmental impact of the pulp and paper industry has been extensively studied, life cycle assessment (LCA) results have not yet reached a consensus. By means of a systematic review and meta-analysis, this article contributes to the quantification and harmonization of the life cycle environmental impacts of pulp making and paper making systems. Based on the screening of 45 cases of paper making and 18 cases of pulp making, we found that 1 t of paper results in about 950 kg carbon dioxide (CO 2 ) equivalent (CO 2 -eq) GHG emissions on average. However, there are distinct differences between countries and pulp and paper categories. The dominant factor influencing GHG emissions is energy use. In paper making, the pulp making process is responsible for 62% of energy use, 45% of GHG emissions, 48% of acidification potential, and 49% of eutrophication potential. The kg CO 2 -eq emissions of three different types of pulp were as follows: Kraft, 508 kg CO 2 -eq/t; chemi-mechanical, 513 kg CO 2 -eq/t; and recycled pulp, 408 kg CO 2 -eq/t. Excluding emissions from electricity and steam production, the convergence of carbon emissions is observed within the same categories of pulp. Straw-based pulp caused far more environmental impact than any other type because of the intensive inputs in agricultural activities as well as in the pulp making process. This research highlighted the inconsistencies in functional units, system boundaries, and methodologies and carbon neutrality assumptions in different LCA studies of pulp and paper making. Future studies should focus on the environmental impact of straw-based pulp making, system boundary unification, and calculation of biogenic carbon emissions. [ABSTRACT FROM AUTHOR]

This work presents the first systematic review analysis of potential Power to Gas integrations in blast furnace ironmaking. The primary objective of the paper is to evaluate the PtG technology implementation in both conventional air-blown and full oxygen blast furnaces, considering different BFG recycling routes (upper, shaft or tuyeres), and synthetic gases (SNG, H2 or syngas). Employing a systematic methodology, the paper compares all the studies using 14 Key Performance Indicators (KPI) and elaborates a discussion on the main findings and limitations, proposing areas for future research. PtG application enables air-blown blast furnaces to cut emissions to 1060 kg CO2 /t HM. With PtG and top gas recycling, oxygen blast furnaces achieve a reduction to 747 kg CO2 /t HM , and when combined with geological storage, the reduction further drops to 435 kg CO2 /t HM. Additionally, the authors propose a novel PtG-ironmaking integration based on the findings of this paper. • First systematic review for Power to Gas in blast furnace ironmaking. • Methodical comparison of technologies using 14 KPIs. • Air-blown blast furnaces emissions can be reduced to 1060 kgCO2/tHM. • Oxygen blast furnaces emissions can be reduced to 435–747 kgCO2/tHM. • Novel power to gas integration proposed by the authors. [ABSTRACT FROM AUTHOR]

This paper develops a framework for a financial, economic, and stakeholder analysis of a residential rooftop solar net-metering program. The empirical focus of the paper is the net-metering program in Ontario, Canada, but the methodology is applicable to evaluating other public programs. The results highlight that without the Federal Government's subsidy for the initial investment cost, net-metered solar systems are not financially viable for representative households. Moreover, the stakeholder analysis reveals that for each additional net-metered system installed in Ontario, non-net-metered households experience financial losses of six times the benefits to the net-metered households. The net losses to the Federal Government of Canada and the Canadian economy are five and nine times the benefit to the net-metered households, respectively. The only stakeholder who benefits marginally is the Government of Ontario. In terms of environmental benefits, our estimate of the cost of greenhouse gas abatement by residential net-metered solar is 325 CAD per ton of CO 2 , which is significantly higher than the current (65 CAD in 2023) and future (170 CAD by 2030) national carbon price set by the Government of Canada. [ABSTRACT FROM AUTHOR]

An optimization model that incorporates all combinatorically feasible inter-plant collaboration networks is developed using P-graph. It has been theoretically proven that time-sliced-based energy planning optimization has positive impacts and is capable of achieving carbon emissions reduction goals and minimizing costs simultaneously. However, as the number of entities increased, an exponential growth in possible combinatorial feasible coalitions is anticipated. Therefore, an extension of the P-graph optimization tool that is capable of generating all possible outcomes in multi-period P2P energy trading – PEP (P-graph for energy planning) is developed. The PEP software can be effectively used in modelling complex process networks graphically and solving optimization problems with the combined advantages of combinatorial algorithms and mathematical programming. In this paper, a systematic framework for implementing P2P energy trading using PEP software is proposed and demonstrated using a real-life case study. [Display omitted] • An optimization tool – PEP software is developed to model P2P energy trading scheme. • The software is capable of generating all possible financial outcomes effectively. • Optimal coalition structure is chosen based on the highest cost savings. • Marginal contribution analysis is done to ensure fair profit distribution. • The sample case study showed that entities can reduce electricity bills by 6.75 %. [ABSTRACT FROM AUTHOR]

Abstract The capacity of installed wind power is growing rapidly in cold climate regions; however, turbine blades are susceptible to ice accumulation. The aerodynamic properties of turbine blades are highly sensitive to ice accretion, which can significantly impair aerodynamic performance. Ice accretion on the blades of a wind turbine can lead to turbine shutdown, power loss and damage to turbine components. To prevent ice formation on wind turbine blades, an ice sensor integrated with an ice mitigation system is required. The ice sensor can be used with a de-icer on the blade surface. However, the current ice sensing and de-icing technologies are inefficient and integrated systems need appreciable improvement. This paper reviews ice sensing and active mitigation techniques for a wind turbine blade surface, which are categorized based on several key parameters. Furthermore, this paper investigates the conceptual design of integrating ice sensing and mitigation systems. The advantages and disadvantages of the integrated systems are presented to provide valuable insights on ice prevention for wind turbines operating in ice prone locations. Highlights • Ice sensing and active mitigation techniques for a wind turbine blade surface. • Review of conceptual designs of integrating ice sensing and mitigation. • Thorough review of advantages and disadvantages of integrated systems. [ABSTRACT FROM AUTHOR]

Abstract The demand for reduction of greenhouse gases, the need for a decreased dependence on fossil fuel, and the increasing penetration of the renewable energy sources are changing the world's electrical energy production. The island of Crete in Greece possesses great potential when it comes to wind and solar energy. Currently, a large amount of wind energy is often being curtailed in Crete, due to the technical minima of the existing thermal units, the inherent fluctuating power output of the wind turbines and the electricity demand profile. Electrical energy storage is recognized as an underpinning technology to have great potential in overcoming these challenges. There are many different ways to store the surplus energy and convert it back to electrical energy when it is needed. The aim of the present paper is the investigation of the role that energy storage can play in the further development of renewable energy sources in non-interconnected islands via considering the energy storage technologies of compressed air energy storage, pumped hydroelectric storage and sodium – sulfur batteries. This paper examines the solution of electrical energy storage in curtailment exploitation. A review over the above energy storage technologies is carried out and a comparative analysis is performed for the case study of Crete. Each storage technology is techno-economically evaluated using actual data. Finally, a parallel comparison of the examined storage systems' levelized cost of energy is presented and conclusions are drawn. The compressed air energy storage system appears to be more favorable, having the lowest levelized cost of energy of the examined systems studied at 0.21 €/kWh, while contributing 105.59 GWh of electrical energy to the island's grid per year. For the examined case study, compressed air energy storage system appears to be almost 20% and 50% cheaper in terms of levelized cost of energy in comparison with pumped hydro storage and batteries respectively. Highlights • Review on compressed air energy storage, pumped hydroelectric storage and sodium – sulfur batteries. • Techno-economic comparative analysis of energy storage technologies for the case study of Crete. • Comparative findings on levelized cost of energy of different storage technologies. [ABSTRACT FROM AUTHOR]

Abstract Energy efficiency measures and climate policies are closely related to strategic concerns of companies, and reduction of greenhouse gas (GHG) emissions has become an important indicator of energy efficiency measures. This paper discusses the application aspects of organizational carbon footprint (CF) for telecommunications companies. In order to better understand the structure of overall (direct and indirect) GHG emission, the model for calculating the organizational CF was established for the case of a telecom operator in its initial stages of carbon policy. In order to understand the importance of scope 3 categories in the overall CF, calculated results were compared to CF results reported by three other European telecommunications operators. The results for a particular case based on Slovenian operator revealed that the largest contributor to GHG emissions is the consumption of purchased electricity. The employees' commute to and from work, the use of company-owned vehicles, and heating represent the next major sources of GHG emissions. It was shown that the most contributive upstream scope 3 aspects are similar for various European telecommunication operators and that exclusion of some categories along the supply chain may give a distorted image of organizational CF. However, the comparative analysis revealed that using only the company's own-recorded in-house data can be far from sufficient to make conclusions which GHG emissions scope contributes the highest share to the overall organizational CF of telecommunications companies. In this context, this paper reveals new findings on the relevance of CF determination for telecommunications companies as a guideline for reconsidering their energy efficiency and sustainability plans. Highlights • Carbon footprint analysis can be used to reconsider the energy efficiency plans of a telecom operator. • The most contributive scope 3 aspects are similar for various European telecommunication operators. • Giving attention to scope 1 and 2 emissions only may be misleading. • Exclusion of scope 3 categories may give a serious distorted image of organizational carbon footprint. [ABSTRACT FROM AUTHOR]

Abstract The requirements made on energy system models have changed during the last few decades. New challenges have arisen with the implementation of high shares of Renewable Energies. Along with the climate goals of the Paris Agreement, the national greenhouse gas strategies of industrialized countries involve the total restructuring of their energy systems. In order to archive these climate goals, fitted and customized models are required. For that reason, this paper focuses on national energy system models that incorporate all energy sectors and can support governmental decision making processes. The reviewed models are evaluated in terms of their characteristics, like their underlying methodology, analytical approach, time horizon and transformation path analysis, spatial and temporal resolution, licensing and modeling language. These attributes are set in the context of the region and time in which they were developed in order to identify trends in modeling. Furthermore, the revealed trends are set in the context of current challenges in energy systems modeling. Combining specified research questions and specific greenhouse gas reduction strategies, this paper will help researchers and decision makers find appropriate energy system models. Highlights • Historical trends in the development of energy system models were analyzed. • Newly-developed models are more flexible in terms of spatial or temporal resolution. • Python has become the most popular programming language in energy systems modeling. [ABSTRACT FROM AUTHOR]

Abstract Growing concerns over the environmental impact of greenhouse gas (GHG) emissions, uncertainty of future fossil fuel prices, geopolitical instability, and consumer preferences are a few factors driving the development and use of biomass as a source of renewable energy. Government mandates and policy frameworks have further built consensus for effective utilization of sustainable resources for energy. As a result, biomass derived densified solid biofuels have experienced a phenomenal growth in the last decade and are expected to grow by 56% during the three decades from 2010 to 2040. Solid biomass represents the largest share of biomass used for heat and electricity generation. Biomass sources range from agricultural, municipal, and commercial wastes, to forest-litter, and energy crops. Because of the varied nature of these sources, harvesting practices and the cost of transportation, several methods have been developed to densify the biomass. The long-term viability and growth of biobased energy products hinges on the technical innovation and wider societal acceptance of these products. This paper reviews multiple biomass feedstock, processing characteristics, product properties, transportation, and storage options. The paper also discusses the economics of densifying biomass, the impacts to regions where biomass utilization is implemented, outstanding challenges, and national and global trends in biomass utilization. Highlights • Biomass feedstocks are major source for densified solid biofuels. • Environmental concerns, GHG gases emission and government mandates driving biomass utilization. • Woody and non-woody biomass represent largest share of biomass for heat and electricity generation. • Biomass feedstock type, preprocessing, densification, and transportation are critical factors for adoption of biomass for energy applications. • Technical innovation and wider societal acceptance important for growth of solid biofuels. [ABSTRACT FROM AUTHOR]

Abstract Global warming due to the emission of greenhouse gases, especially carbon dioxide (CO 2), has a significant effect on the climate change and has become a widespread concern in the recent years. Carbon capture, utilization, and sequestration (CCUS) strategy appears to be effective in decreasing the carbon dioxide level in the atmosphere. Despite a great progress in this field, there are still major limitations in commercialized the CO 2 capture methods that rely on absorption phenomena. High capital costs of for the CO 2 capture, low absorption and desorption rates (which require large facilities), solvent losses due to evaporation, and the use of corrosive solvents are among main obstructions. Recently, CO 2 capture with ionic liquids (ILs) has appreciably attracted researchers’ attention. The distinct properties of ILs such as negligible vapor pressure and their affinity to capture the CO 2 molecules make them a feasible alternative for currently available solvents including, different amines. This paper covers a brief review of previous engineering and research works on various CO 2 capture techniques, the description of CO 2 capture process using ILs, mechanisms of the CO 2 capture with ILs at molecular level, CO 2 and ILs properties, characterization of the CO 2 /IL systems, impacts of operating and fluids conditions on CO 2 absorption capacity by ILs, and CO 2 solubility and selectivity in ILs. Moreover, the technical and economic aspects of the CO 2 capture with ILs, screening criteria for ILs/CO 2 systems, and important results obtained from previous studies will form the last parts of this manuscript. This review offers a proper/systematic guideline that assists researchers and engineers to comprehensively understand and to effectively design the CO 2 /ILs processes, focusing on the thermodynamic and mass transfer aspects. Highlights • CO 2 capture with ionic liquids (ILs) appears to be a promising strategy in the future. • This review paper describes carbon capture process using ILs, mechanisms, and challenges. • This paper discusses about different characterization tools for ILs/CO 2 systems. • CO 2 capture efficiency is studied at various conditions through parametric sensitivity analysis. • Technical and economic aspects and screening criteria for ILs/CO 2 systems are highlighted. [ABSTRACT FROM AUTHOR]

The development of cleaner and renewable energy sources are necessary so that fossil fuel dependency and global warming can be reduced. Present communication is an attempt to explore the available literature on Photovoltaic Thermal (PVT) air collectors and PVT air collector integrated greenhouse drying system. Solar drying is one of the best method to preserve crops for a long time. In developing and under developed countries; per capita electricity production is low; therefore the electricity uses for heating purpose cannot be economically and environmentally justified option. In previous studies, it was found that forced drying is better in terms of controlling drying parameters and PVT air collector is better than standalone PV module in terms of energy storage. In present review paper, combination of PVT air collector and drying system has been discussed. Moreover, thermal modelling of PVT air collector integrated greenhouse drying system has been presented in detail. Average thermal efficiency, electrical efficiency and overall thermal efficiency for PVT air collector are found to be 26.68%, 11.26% and 56.30% respectively at 0.01 kg/s mass flow rate of air. This review paper may be very helpful for researchers and scientists to develop thermal models for different hybrid solar systems. [ABSTRACT FROM AUTHOR]

Global depletion of fossil fuels, growing awareness on the effects of carbon emissions and greenhouse gases and, the need for renewable energy, has increased the attention towards biocoke research and active engagement with various research groups and industrial players. Biocoke production and utilisation is crucial as it contributes to the efficient management of agricultural residue and municipal solid waste. The technologies involved in the biocoke production and the viability of Malaysia's agricultural waste as a feedstock was described in this paper. In addition, the paper provided background information about the biocoke characteristics and the feedstocks that dictate quality. Comparisons of commercial coal coke and biocoke production technologies that may be applicable to Malaysia were also addressed. Moreover, the paper demonstrated the challenges towards Malaysia's biocoke commercialisation despite its viability from biomass feedstocks characteristics, availability, and evidence of calorific value estimations. [ABSTRACT FROM AUTHOR]

The built environment is one of the major contributors of greenhouse gas (GHG) emissions. To tackle climate change, global targets have been set for this sector. Although life-cycle assessment (LCA) methods are typically used to evaluate a building project's embodied energy in its final stages of development, this evaluation would be especially valuable at early design stages, when the opportunity to modify the design is greatest. In this paper, an extensive review of methods to improve the usability of LCA at the early design stage is presented. Three major issues regarding the application of LCA arose from this analysis at this stage: its time consumption, the lack of design details, and the non-reproducibility of results. Moreover, LCA makes it possible to assess environmental performance, but does not provide design alternatives, which are crucial to introduce environmental targets into an iterative design process. To that end, existing techniques that can address the major LCA issues were identified, together with their respective limits. These include some promising tools that provide and explore design alternatives and their respective environmental performances. Among these tools are exploration methods, which have not been applied to LCA insofar as it is not possible to do so in a reasonable computational time. To bridge this gap, the paper outlines the structure of an LCA-based data-driven design method, which uses a combination of LCA, parametric analysis, data visualization, sensitivity analysis, and target cascading techniques. [ABSTRACT FROM AUTHOR]

Observing present scarcity of fossil fuel and emissions of greenhouse gases, electricity generated from Renewable Energy (RE) sources turns out to be the best alternative for generating the power. In RE system, the inverter is normally used to condition the DC power into AC to meet the requirements of load and transmission system. The inverter offers myriad benefits; however, the presence of harmonics (particularly low-order) in the output voltage affects the efficiency and performance of inverter, causes switching losses and decreases the lifetime of the system. In last three decades, significant research has been done to develop the efficient control technique for eliminating the unwanted harmonics. The preliminary review of existing control techniques revealed that the selective harmonic elimination pulse-width modulation (SHEPWM) is more proficient to eliminate the low-order harmonics. However, non-linear transcendental equations used in this technique pose a challenge to solve particularly for calculus-based methods. With the advent of powerful and low-cost computers, bio-inspired intelligent algorithms (BIAs) seem to be a better approach for solving these complex equations. This review paper presents the detailed principle operation of nine well-known BIAs and discusses their application in inverters for harmonic elimination (HE). Moreover, different objective functions are also discussed in this paper which is used by the researchers for HE. Additionally, the performance of five renowned BIAs, namely, Imperialist Competitive Algorithm, Particle Swarm Optimization, Differential Evolution, Bee Algorithm and Genetic Algorithm is critically evaluated. Their performance is analyzed in terms of accuracy, computational complexity, convergence speed, and a number of control parameters. The conclusion has been made on the basis of information extracted from the literature and evaluation results with future recommendations. This single paper covers all the essential information regarding HE in inverters, which will help researchers to design the efficient RE conversion system. [ABSTRACT FROM AUTHOR]

From an environmental point of view, reduced use of energy remains a cornerstone in global greenhouse gas mitigation. However, without full internalization of external costs, greenhouse gas mitigation as such may not be highly prioritized among business leaders. Rather, it is the magnitude of production costs and ultimately the size of market revenue that articulates success or failure for business leaders. Nevertheless, reduced energy use or improved energy efficiency can have a vast impact on profitability even for companies with low energy costs, as the reduced energy costs directly lead to increased profits. In this paper, a review of ten years of empirical research in the field of industrial energy management in Swedish industry is presented. Based on the review, the paper proposes success factors for efficient energy management, factors which could help guide individual energy managers as well as policy makers in order to close the energy efficiency and management gaps. The paper also presents an overview of important industrial energy management tools, which would facilitate in-house energy management in industry. [ABSTRACT FROM AUTHOR]

To address issues of energy security and greenhouse gas (GHG) mitigation, substantial amounts of corn-derived ethanol are being used in U.S. gasoline. Currently, ethanol comprises 10% of the U.S. gasoline pool (E10), but there is interest in increasing this – possibly doubling the amount currently used. Production of corn ethanol raises several concerns with respect to environmental and ecological impacts. This paper reviews the available literature regarding impacts on biodiversity, land use change (LUC), greenhouse gas (GHG) emissions, and overall sustainability. A companion paper addresses impacts on water, soil, and air quality. We emphasize recent information appearing since comprehensive reports on these topics were issued by the U.S. EPA and NRC/NAS in 2011. The principal environmental and ecological concerns arise from the intensive agricultural activities associated with corn cropping. Expansion of these activities promotes regional mono-culture, which is accompanied by reduced plant and animal biodiversity, and diminished ecosystem functions and services. Extensification of corn cropping into Conservation Reserve Program (CRP) lands is occurring, which raises concerns about erosion, nutrient runoff, and other adverse environmental impacts. Estimating the impacts of increased ethanol on GHG emissions requires sophisticated life cycle assessment (LCA) modeling approaches to account for emissions resulting from land use change (LUC). Although considerable uncertainty remains, recent regulatory modeling by EPA and CARB estimate modest GHG reductions of about 20% from corn ethanol as compared to gasoline. Being a major commodity in global food/feed markets, displacing large amounts of corn to produce ethanol strengthens demand and increases prices. To date, these effects have been small, but there are growing concerns about increased use of staple food products to produce fuels within the context of an expanding global population that faces severe calorie shortages. Tradeoffs regarding environmental, ecological, and social impacts raise questions about the overall sustainability of such an approach. [ABSTRACT FROM AUTHOR]

To address issues of energy security and greenhouse gas (GHG) mitigation, substantial amounts of corn-derived ethanol are used in U.S. gasoline. Currently, ethanol comprises 10% of the U.S. gasoline pool (E10), but there is interest in increasing this – possibly doubling the amount currently used. Production of corn ethanol raises several concerns with respect to environmental and ecological impacts. This paper reviews the available literature regarding the impacts on water, soil, and air quality. A companion paper addresses issues of biodiversity, ecosystems, land use change, greenhouse gas (GHG) emissions, and sustainability. We emphasize recent information appearing since comprehensive reports on this topic were issued by the U.S. EPA and NRC/NAS in 2011. The principal environmental concerns arise from the intensive agricultural activities associated with corn cropping. Nutrient runoff contributes to eutrophication, algal growth, and hypoxia in downstream water bodies; in addition to elevated nitrate pollutant levels in drinking water sources. Water requirements of corn ethanol vary by over 2-orders of magnitude among corn-growing states, depending upon the amount of irrigation used. Significant increases in corn production would likely involve expansion into areas requiring more intensive irrigation. Expansion into Conservation Reserve Program (CRP) lands raises concerns about increased erosion, deterioration of soil quality, loss of biodiversity, and reduction of ecosystem services. Largely because of energy-intensive agricultural activities (including fertilizer production), upstream emissions of most air pollutants of concern are considerably higher for corn ethanol compared to gasoline. Current fuel ethanol levels do not provide any benefit with respect to ground level ozone, and this is unlikely to change with use of E20. However, externalities associated with life-cycle emissions (such as eutrophication, acidification, health effects, etc.) are greater – and more costly – for corn ethanol compared to gasoline. Such externalities are expected to worsen in moving from E10 to E20 fuels. [ABSTRACT FROM AUTHOR]

Energy-intensive processing industries (EPIs) produce iron and steel, aluminum, chemicals, cement, glass, and paper and pulp and are responsible for a large share of global greenhouse gas emissions. To meet 2050 emission targets, an accelerated transition towards deep decarbonization is required in these industries. Insights from sociotechnical and innovation systems perspectives are needed to better understand how to steer and facilitate this transition process. The transitions literature has so far, however, not featured EPIs. This paper positions EPIs within the transitions literature by characterizing their sociotechnical and innovation systems in terms of industry structure, innovation strategies, networks, markets and governmental interventions. We subsequently explore how these characteristics may influence the transition to deep decarbonization and identify gaps in the literature from which we formulate an agenda for further transitions research on EPIs and consider policy implications. Furthering this research field would not only enrich discussions on policy for achieving deep decarbonization, but would also develop transitions theory since the distinctive EPI characteristics are likely to yield new patterns in transition dynamics. [ABSTRACT FROM AUTHOR]

For China, greenhouse gas emissions increased by 0.075 gigatons (Gt) in the period of 1995–2000 and increased by 4.23 Gt from 2000 to 2009, then reached the amount of 8.61 Gt in 2009. Different from the traditional analysis focused on accounting sectors’ greenhouse gas emissions under the production-based responsibility, this paper investigates sectoral GHG emissions in China in the period of 1995–2009 from the perspective of consumption-based and income-based responsibility. We found that different metrics yield very different GHG emission responsibilities. The sector of electricity, gas and water supply has the highest GHG emissions responsibility based on the production and income metrics, while the sector of construction is the largest emitter under the consumption metric. In the light of the key driver analysis of GHG emissions from 1995 to 2009, based on the consumption metric, the change in the final demand volume is the largest driver of increase in China's consumption-based GHG emissions (+17.18 Gt). The changes in the production structure and the final demand structure are other contributors (+0.53 Gt, +1.46 Gt). The improvement to the intensity of GHG emissions is the main force for GHG emissions mitigation (−14.86 Gt). According to the income metric, the contributions of input volume changes, input structure changes and GHG intensity changes are similar to the effects of consumption-based responsibility (+19.11 Gt, +1.13 Gt, −14.95 Gt). The difference is that the change in the production structure is another force that offset GHG increase (−0.98 Gt). Results in this paper can give some recommendation on mitigating GHG emissions in China for policy-makers from production-side, demand-side and supply-side. [ABSTRACT FROM AUTHOR]

Society's dependence on fossil fuels to meet energy demands has resulted in an enormous release of greenhouse gas (GHG) emissions into the atmosphere, thereby perpetuating global climate change. The consequences of climate change have prompted progressive governments such as British Columbia to establish legislative GHG emission reductions targets, which have lead to energy conscience municipalities within the province voluntarily committing to helping achieve such targets. Best practices examined from European municipalities share a common theme of renewable energy adoption and municipally-owned utilities. An emerging renewable energy technology are tidal current turbines (TCTs), which function to extract kinetic energy from the lateral movement of the tides in areas with considerable tidal velocities. This paper examines the history, physics, operational parameters, and plausible environmental impacts of TCTs in order to make a case for their sustainable implementation. The feasibility of the municipalities of North Pender Island, South Pender Island, and Saturna of the Southern Gulf Islands Region (SGIR), British Columbia, to help meet established GHG emissions reduction targets through the implementation of TCTs is analyzed, demonstrating that the deployment of 10 TCTs can produce 38,266,602 kWh/yr of electricity, mitigating 1138 t of CO2e, achieving 9.9% of the cumulative municipal GHG emissions mitigation targets. The paper then examines a case study in the Shetland Islands and Pentland Firth and Orkney Waters, Scotland, suggesting that jurisdictional regulatory powers over TCT installation and operation be devolved from the British Columbia government to the municipal governments of North Pender Island, South Pender Island, and Saturna, so that such communities can reap the benefits associated with a municipally-owned utility. [ABSTRACT FROM AUTHOR]

Global anthropogenic activities resulting in the emission of harmful greenhouse gases (GHGs) to the atmosphere have increased the challenges faced from climate change. The greater awareness of the need to mitigate climate variability has brought about intense focus on the adverse impacts of fossil-fuel based energy on the environment. Being the single largest source of carbon emissions, energy supply has attracted much attention and more so that, climate change impacts extend beyond national boundaries. Since energy use is sine qua non to economic development, scientists have reiterated the necessity of developing and utilising renewable energy. Although, past and present CO 2 emissions have and are majorly caused by industrialized countries, it is envisaged that future GHGs emissions would be mostly from developing countries as they industrialize. Renewable energy sources that include biomass, hydroelectric, wind, solar and hydrothermal systems, are carbon-neutral, releasing relatively no emissions. This paper discusses the initiatives associated with the provision of renewable energy to the energy mix in Nigeria as an indication of the country’s commitment to adopt a sustainable development strategy in shaping the economy. It reviews the literature and employs a discourse analysis to examine the limited use of renewable energy sources in Nigeria and the factors prevailing against their development. The paper concludes by identifying social and political obstacles as most significant roadblocks towards rapid implementation of a green economy through the deployment of renewable energy for sustainable development. [ABSTRACT FROM AUTHOR]

Carbon emissions trading (CET) is a market mechanism, aims to promote the control of globe greenhouse-gas emissions. It is an important part of international environmental cooperation and it is also the important application research filed of environmental economics and institutional economics. There is a very obvious phenomenon that the publications about CET increasing year by year. This paper adopts the scientometric analysis method to assess the current state and explore the development trends of carbon emission trading domain based on the literature data retrieved from Web of Science. The research results of this paper could answer the following questions clearly. 1) Which subject category is the most popular in CET research area? Which journal published the most number of articles in this area? Which institution and country is the most productive in CET domain? 2) What are the major research areas and what documents are the most cited? Which journal are the most representative in CET research domain? 3) What are the new emerging trends and development in CET research area? On the whole, the research method in this paper provided a fresh research approach to assess the performance of CET research. The findings may help for the new researchers to pick out the most relevant articles, journals, institutions and seize the research frontier in CET field. [ABSTRACT FROM AUTHOR]

The major contributor to global warming is human-generated greenhouse gases (GHGs) emissions that pollute the air. GHGs emissions are a global issue dominated by emission of carbon dioxide (CO 2 ). Notably, CO 2 accounts for an estimated 77% of GHGs and thus has a huge impact on the environment. The capture, sequestration, and utilization of CO 2 emissions from flue gas are now becoming familiar worldwide. These methods are a promising solution to promote sustainability for the benefit of future generations. Previously, many researchers have focused on capturing and storing CO 2 ; however, less effort has been spent on finding ways to utilize flue gas emissions. Moreover, several issues must be overcome in the field of carbon capture and sequestration (CCS) technology, especially regarding the cost, capacity of storage and the durability of the storage reservoir. In addition, this paper addresses new technology in carbon capture and sequestration. To make CCS technology more feasible, this paper suggests a sustainable method combining CCS and biofuel production using CO 2 as a feedstock. This method offers many advantages, such as CO 2 emission mitigation and energy security through the production of renewable energy. Due to the many advantages of biofuels, the conversion of CO 2 into biofuel is a best practice and may provide a solution to pollution while encouraging sustainability practises. [ABSTRACT FROM AUTHOR]

The electric vehicle (EV) technology addresses the issue of the reduction of carbon and greenhouse gas emissions. The concept of EVs focuses on the utilization of alternative energy resources. However, EV systems currently face challenges in energy storage systems (ESSs) with regard to their safety, size, cost, and overall management issues. In addition, hybridization of ESSs with advanced power electronic technologies has a significant influence on optimal power utilization to lead advanced EV technologies. This paper comprehensively reviews technologies of ESSs, its classifications, characteristics, constructions, electricity conversion, and evaluation processes with advantages and disadvantages for EV applications. Moreover, this paper discusses various classifications of ESS according to their energy formations, composition materials, and techniques on average power delivery over its capacity and overall efficiencies exhibited within their life expectancies. The rigorous review indicates that existing technologies for ESS can be used for EVs, but the optimum use of ESSs for efficient EV energy storage applications has not yet been achieved. This review highlights many factors, challenges, and problems for sustainable development of ESS technologies in next-generation EV applications. Thus, this review will widen the effort toward the development of economic and efficient ESSs with a longer lifetime for future EV uses. [ABSTRACT FROM AUTHOR]

With pressure to reduce greenhouse gas emissions from the energy and other sectors, policymakers are increasingly seeking to mobilise investment in renewable electricity with support mechanisms. The objective of this paper is to assess the value of utility-scale solar PV using a multidisciplinary approach. In many cases renewable energy strategies are developed by investors and policymakers on the basis of a relatively narrow analysis of costs. However, as policies should be designed to maximise societal welfare, a wider paradigm is needed in decision-making. This paper argues for an impact assessment of renewable electricity generation that integrates its value from investor, utility, policy maker and end-user perspectives. We propose a multidisciplinary approach to the assessment, combining engineering production cost estimation with financial and market analysis of utility-scale solar PV in Ireland. The results show that while from an investor's perspective solar PV generation is, and will likely remain so for the foreseeable future, relatively expensive in a country with low solar irradiation such as Ireland, there are benefits for the electricity system in terms of reduced wind curtailment and, to a lesser extent, CO 2 emissions. This demonstrates why the wider costs and benefits of integrating a renewable electricity technology to the system need to be considered in assessment of renewable policy support mechanism. Policy makers can then seek to maximise the system benefits while minimising the cost of any policy supports. [ABSTRACT FROM AUTHOR]

A pursuit of environment conservation as well as a fluctuated rise in diesel price has moved worldwide interests towards biodiesel, a kind of clean and renewable alternative fuel for the diesel engines. However, owing to heterogeneous mixing between the air and fuel, particle matter(PM) emissions have always been a main concern in the development of the diesel engines, especially in the face of continuously updated and progressively stringent PM emission regulation. Therefore, this paper sorts out and analyzes the studies published chiefly in scientific journals about particle matter emissions of the diesel engines used biodiesel or biodiesel/diesel blends as fuels compared with those from the traditional diesel fuels. The paper mainly includes the following sections. The first section deals with the fundamentals of particle matters from the biodiesel combustion including particle composition, physical and chemical properties. In the next, particle formation mechanism as well as PAH formation is introduced briefly. The effects of biodiesel property on particle emission are discussed in the third section. Then, the effects of operating parameters of the engines on PM emissions have been analyzed in the fourth section. After that, the influences of biodiesel blending on diesel particulate filter (DPF) and radiocarbon ( 14 C) analysis of biodiesel particles have been reviewed. At last, general conclusions are summarized and further research targets are proposed in this paper. [ABSTRACT FROM AUTHOR]

This review paper is devoted to elaborating the status of different energy policy planning studies and the evaluation of various GHG mitigation studies. It includes, some of the major developments in global energy scenario, status of Green House Gas (GHG) emissions, issues in the implementation of Kyoto protocol and GHG mitigation, Clean Development Mechanism (CDM) and energy scenario especially pertaining to the residential, industrial and commercial energy sector in the initial sections. The later part of this paper highlights the salient contributions in various literatures pertaining to energy demand forecasting in residential, commercial and industrial sector, GHG estimation methodologies, and GHG mitigation studies in various sectors. The success and difficulties in implementing various policy planning practices were also discussed in the paper. Most of the prominent literature in the area of energy demand and consumption analysis towards effective implementation of GHG mitigation is described. In the end, a comprehensive comments and recommendations based on the study were furnished. [ABSTRACT FROM AUTHOR]

By exploiting the 3 K coldness of outer space as heat sink of terrestrial thermal radiation, passive daytime radiative cooling (PDRC) can achieve sub-ambient temperatures without any energy consumption, and thus exhibiting extraordinary application potentials. By pursuing the dual-band (solar and atmosphere window) optical properties to approach ideal 100 %, PDRC can maximize dissipating long wavelength infrared radiation to space and minimize absorbing sunlight simultaneously. PDRC technology can reach146 W/m2 theoretical cooling power and up to 120 W/m2 during application. This article focuses on the fundamental physics mechanism of radiative transfer and natural radiative cooling phenomena. Methodologies of infrared absorption functional group selection, optical band gap selection for solar reflection, photon and phonon enhanced resonance by micro-structure were discussed in detail to give a comprehensive instructing strategy of radiative cooling power improvement. Although PDRC technology can achieve sum-ambient temperature cooling without consuming any energy, its drawbacks such as single function of cooling and high whiteness requirement needed to hinder its large-scale application. This article also outlines the current primary applications of PDRC technology, along with summarizing the challenges and potential opportunities it encounters in practical implementation. This paper aims to provide a comprehensive overview on the fundamental physical mechanisms, methods for enhancing its power output, as well as the current state and future developments of PDRC applications, providing potential guidance for reducing greenhouse gas emissions and energy consumption. • Advancements of radiative cooling technology were reviewed comprehensively. • Fundamental physics of passive radiative cooling was reviewed comprehensively. • Material selection methodology and optical mechanism were discussed in detail. • The recent application of passive daytime radiative cooling was reviewed. • Some current challenges and potential applications were presented and discussed. [ABSTRACT FROM AUTHOR]

Air source heat pumps are an excellent electric alternative to fossil fuel based heating systems for reducing residential greenhouse gas emissions, but common mild climate systems suffer significant performance losses at the low outdoor air temperatures experienced in regions with cold climates. Improved heat pumps for cold climates are available on the market, but they are more expensive and their adoption to date has been relatively low, suggesting that there is work yet to be done in this field. This paper presents an analysis of market-available air source heat pumps identifying and discussing the cold climate technologies found in residential centrally-ducted cold climate systems. It shows that all of these heat pumps use rotary or scroll type variable-speed compressors, accumulators, and reverse cycle defrosting, and that a small number also include refrigerant injection and/or specialized refrigerant charge management devices. Available performance data for these heat pumps reveal that most of these systems still exhibit a significant loss of heating capacity at cold temperatures and are unlikely to meet the entire heating needs of a home in regions where temperatures drop below −15 °C, necessitating the use of auxiliary heating systems. A review of the literature on cold climate heat pumps is also included to highlight additional design concepts and innovations that have not yet been implemented by the industry, but might further improve the performance and uptake of heat pumps in cold climates. • The technical challenges facing air source heat pumps in cold climates are described. • Market-available cold climate air source heat pump technologies are analysed. • Most market-available systems operate on single-stage thermodynamic cycles. • New testing and rating methods are recommended to compare cold climate performance. • Cold climate innovations not yet implemented by the industry are highlighted. [ABSTRACT FROM AUTHOR]

Electricity supply in remote areas of the Russian territory is heavily dependent on diesel sources. Diesel generation imposes an important economic and social burden on the local population, besides the environmental impact of greenhouse gas emissions, black carbon and oil spills. Switching to renewable energy could reduce the current economic, social and environmental cost of electricity supply in Russia׳s remote areas. The objective of this paper is to review Russia׳s off-grid renewable energy policy by focusing on the promotion of wind- and solar-diesel hybrid energy in the Russian Arctic. Taking a mainly regulatory perspective, this paper identifies existing barriers to the development of hybrid renewable-diesel investments. Building further on the international experience with the promotion of renewable energy in Arctic climates ( e.g., in Alaska and Canada), this paper tests the feasibility of alternative ‘best practice’ mechanisms to support off-grid renewable energy in Russia. [ABSTRACT FROM AUTHOR]

Renewable energy sources have a huge potential to reduce greenhouse gas emissions and decrease the dependence on fossil fuels in the energy sector. However, the energy output of these sources is variable and raises concerns regarding the electric grid reliability. Therefore, the deployment of energy storage would play a key role in enabling the integration of these sources in the electric grid. This paper proposes methods for determining the optimal operation and sizing of energy storage systems. The main purpose of the operation strategy is to maximize the revenues of the renewable farm. The sizing model, on the other hand, has a purpose to minimize the cost of the hybrid system while meeting the service requirement. Both methods were formulated as non-linear programming optimization models. To verify the effectiveness of these methods; case studies have been presented. Finally, this paper proposes an economical analysis to determine the cost added by the storage to each KWh of stored energy. [ABSTRACT FROM AUTHOR]

Cities contribute around 80% of global greenhouse gas emissions. There is currently a massive growth in urban areas internationally, especially in developing countries. Urban centers and cities should offer an effective answer to new problems arising from planning and expansion, according to criteria of sustainability. Decisions for sustainable cities planning and management should be taken on an evaluation of their consequences. Correspondingly, each strategy should be designed and undertaken with the right tools of study, analysis and prediction. This paper aims to offer an analysis of the aspects involved in designing sustainable cities. It involves an overview of published papers focusing on urban transport, building energy consumption, green areas planning, waste management and water supply on a city-wide scale. In order to give a broader concept of sustainability in cities, an analysis of other variables from a social point of view is also given. The discussion of this research reflects that the adoption of mechanisms to promote sustainable development is a matter not only of decision makers and designers, but also of users and citizens. [ABSTRACT FROM AUTHOR]

Energy is the largest overhead cost in the production of agricultural greenhouse crops in temperate climates. Moreover, the initial cost of fossil fuels and traditional energy are dramatically increasing. The negative environmental impacts, limited sources of fossil fuels and a high consumption of energy and food have caused the increase in demand for solar energy as a green and sustainable choice. Therefore, this paper reviews the solar energy application technologies in the environmental control systems of greenhouses (cooling, heating and lighting) mainly the generated energy of photovoltaic (PV) and solar collectors, as well as the PV water pumping for irrigation. Furthermore, this paper briefly discusses the economic analyses and the challenges for this technology. [ABSTRACT FROM AUTHOR]

Emerging issues on fuel price and greenhouse gas emissions have attracted attention on the alternative energy sources, especially in transportation sector. The transportation sector accounts for 40% of total fuel consumption. Thus, an increasing number of studies have been conducted on hybrid electric vehicles (HEVs) and their energy management system (EMS). This paper focuses on reviews of EMSs for fuel cell (FC) based HEV in combination with battery and super-capacitor, respectively. Various aspects and classifications of fuel cell–HEV EMS are explained in this paper. Different types of FC–HEV control models and algorithms derived from simulation and experiment are explained in details for an analytical justification for the most optimal control strategy. The performances of the various combinations of FC–HEV system are summarized in the table along with relevant references. This paper provides comprehensive survey of FC–HEV on their source combination, models, energy management system (EMS) etc. developed by various researchers. From the rigorous review, it is observed that the existing technologies more or less are capable to perform well; however, the reliability and the intelligent systems are still not up to the mark. Accordingly, current issues and challenges on the FC–HEV technologies are highlighted with a brief suggestions and discussion for the progress of future FC–HEV vehicle research. This review will hopefully lead to increasing efforts towards the development of economic, longer lifetime, hydrogen viable, efficient electronic interface and well performed EMS for future FC–HEV. [ABSTRACT FROM AUTHOR]

Lithuania has developed several important climate change mitigation policy documents however there are no attempts in Lithuania to develop local climate change mitigation policies or to decentralize climate change mitigation policy. The aim of the paper is to analyse climate change mitigation policies in households. The paper presents the framework for the assessment of reasonably achievable GHG emission reduction (RAER) potential in households based on behavioral changes related to energy consumption. The paper presents the results of empirical application of developed framework in Lithuanian households. Community based social marketing approach was implemented and GHG emission reduction potential was assessed in focus groups of Kaunas region county during preparation of sustainable development strategy and long-term strategic development plan for Kaunas region county. [ABSTRACT FROM AUTHOR]

Toward efforts to improve sustainability of energy supply and to achieve worthwhile reduction in greenhouse gas emissions, in addition to the increased use of renewable energy sources in buildings, more emphasis is being placed on the need for improved control, management and coordination of building operations and its interaction with the smart-grid. Multi-agent system (MAS), due to its distributed and autonomous properties is considered a viable tool for improving the coordination and management of interactions between buildings and components of the smart-grid. This paper provides an overview of the application of multi-agent systems in building operations for coordination of various building processes and buildings interaction with the smart-grid. By first reviewing the notions of agents, its potentials and key attributes, the paper identifies key areas in building operation where its application provides improved performance. Furthermore, the paper provides a discussion on the knowledge gaps, challenges with its uptake in practical building application as well as opportunity for concentrated research. [ABSTRACT FROM AUTHOR]

The co-benefits approach is a concept that aims to align the climate change issue with the local development goals. The premise of this approach is that the mainstreaming of the climate mitigation issue within the local level polices will result in various local environmental and non-environmental co-benefits in addition to a reduction of GHG emissions. The implementation of the co-benefits approach aims to strengthen the policy making process, which is identified as being especially important in context of developing cities. This paper attempts to confirm this by analyzing a planning process of and global and local benefits generated by an innovative project related to provision of bicycle parking. The paper firstly overviews recent co-benefits literature related to urban transport in general and active travel in particular, as well as evaluated benefits related to bicycle infrastructure provision. Then, taking the case of the Serbian city of Novi Sad, this paper examines local drivers behind the bicycle project implementation, the reduction of CO 2 emission generated by the increase of cycle commuters, the project impact on individual commute behavior as well as potential for income generation. The results support arguments towards relevance of implementation of the co-benefits approach within processes of cycling planning and popularization, particularly highlighting the role and possibilities for implementation of co-benefits projects related to bicycle parking facilities. This case study is relevant as it identifies and analyses a real-life action to respond to both, global and local sustainability challenges, but also, as it points to an action at the city level that has potential for diffusing desirable changes into wider society. [ABSTRACT FROM AUTHOR]

In 2007 was settled the first minimum energy performance standards for air conditioners in Brazil. After more than 14 years since the first regulations and looking upon future perspectives, this paper presents a review of regulatory developments in the country and an assessment based on scenario simulation to verify potential impacts of new minimum energy performance standards for air conditioners. The methodology employed is a bottom-up approach designed to estimate the energy consumption of air conditioners. A spreadsheet-based computational tool was developed to perform sensitivity analysis of key parameters such as ownership rate, average temperature and cooling degree days. The results show a significant energy savings potential that could be captured through a minimum energy performance standards revision. For the scenarios simulated these savings potential would reach up to 417 TWh, with respective greenhouse gases emissions reduction that would be 249 million tons, over the period from 2023 to 2040. An economic analysis of minimum energy performance standards impact is also provided and indicate that even in conditions that involve higher costs and discount rates, new more restrictive minimum energy performance standards allow capturing significant benefits for the society as a whole and for consumers individually. Reviewing the minimum energy performance standards is a critical and urgent issue for Brazil and the methodology presented in this paper can be useful in the process of decision-making related to new regulatory developments. • More restrictive MEPS for air conditioners is urgently needed in Brazil. • The synergy between the CGIEE, Procel and PBE/INMETRO should be improved. • The methodology presented in the paper can support the process of MEPS revisions. • Energy, economic and environmental benefits of more stringent MEPS can be very significant. [ABSTRACT FROM AUTHOR]

Wind energy is a mature and cost-effective solution to greenhouse gas emission reduction and climate change mitigation. Wind resource assessment is the most pivotal activity before wind farm development since it determines the bankability of the wind project. Based on the joint use of a Doppler wind sodar (sonic detection and ranging) system and a microwave radiometer, this paper investigates the wind and thermal characteristics and wind energy resources in a coastal region of Hong Kong. First, wind climatology and variability, as well as their correlation with large-scale and local meteorological and geographical conditions, are analyzed and discussed. Then, statistical distributions of wind speed are evaluated, and the goodness-of-fit of the Weibull, Kappa, Wakeby, Normal-Weibull mixture, and Weibull-Weibull mixture distributions is assessed. Subsequently, the probability distribution and variation of atmospheric stability are examined, and their effects on vertical wind shear, wind profile, and wind speed at turbine hub height are revealed. Lastly, the spatiotemporal variation of wind power density is investigated with attention paid to air density. The results presented in this paper are expected to offer insights into coastal wind and thermal characteristics, provide references for vertical extrapolation of wind speed and wind turbine load evaluation, and facilitate wind farm development in coastal regions. • Investigation of coastal wind climatology and variability in Hong Kong. • Evaluation of statistical distributions of wind speed, gradient Richardson number, and air density. • Exploration of vertical variation of wind speed, air density, and wind power density. • Analysis of wind shear coefficient under different atmospheric stability conditions. • First known study of wind resources that jointly uses sodar and microwave radiometer. [ABSTRACT FROM AUTHOR]

In recent years, a significant interest in hybrid and battery electric vehicles has arisen globally due to reducing fuel consumption, mitigating dependence on imported oil and decreasing greenhouse gas emissions. The overall success of these vehicles mostly depends on the performance of sub-systems that they are created. In order to enhance the performances of these sub-systems, estimation of their parameters with high accuracy is required. Furthermore, estimation strategies play an important role in battery management, vehicle energy management and vehicle control by undertaking different tasks. There have been a limited number of review studies related with estimation strategies that are only focused on battery state of charge (SOC) and state of health (SOH) estimation. This paper presents a comprehensive review on various estimation strategies used in hybrid and battery electric vehicles for the first time in the literature. The existing estimation strategies are classified and different methodologies used in each estimation strategy are elaborated. Recent research advances on existing estimation strategies are clearly emphasized by reviewing numerous studies over 200 papers. [ABSTRACT FROM AUTHOR]

Biomass fuels have long been accepted as useful renewable energy sources, especially in mitigating greenhouse gases (GHG), nitrogen oxides, and sulfur oxide emissions. Biomass fuel is carbon neutral and is usually low in both nitrogen and sulfur. For the past decade, various forms of biomass fuels have been co-combusted in existing coal-fired boilers and gas-fired power plants. Biomass is used as a supplemental fuel to substitute for up to 10% of the base fuel in most full commercial operations. There are several successful co-firing projects in many parts of the world, particularly in Europe and North America. However, despite remarkable commercial success in Europe, most of the biomass co-firing in North America is limited to demonstration levels. This review takes a detailed look at several aspects of biomass co-firing with a direct focus on North America. It also explores the benefits, such as the reduction of GHG emissions and its implications. This paper shows the results of our studies of the biomass resources available in North America that can be used in coal-fired boilers, their availability and transportation to the power plant, available co-firing levels and technologies, and various technological and environmental issues associated with biomass co-firing. Finally, the paper proffers solutions to help utility companies explore biomass co-firing as a transitional option towards a completely carbon-free power sector in North America. [ABSTRACT FROM AUTHOR]

Electric energy security is essential, yet the high cost and limited sources of fossil fuels, in addition to the need to reduce greenhouse gasses emission, have made renewable resources attractive in world energy-based economies. The potential for renewable energy resources is enormous because they can, in principle, exponentially exceed the world׳s energy demand; therefore, these types of resources will have a significant share in the future global energy portfolio, much of which is now concentrating on advancing their pool of renewable energy resources. Accordingly, this paper presents how renewable energy resources are currently being used, scientific developments to improve their use, their future prospects, and their deployment. Additionally, the paper represents the impact of power electronics and smart grid technologies that can enable the proportionate share of renewable energy resources. [ABSTRACT FROM AUTHOR]

At present achieving fuel economy and reducing emissions are the two main targets set by the automotive industries. Homogeneous charge compression ignition (HCCI) technology is believed to be a promising one to be applied in both spark ignition (SI) and compression ignition (CI) engines in the near future. However, some challenges such as compromise combustion phase control, controlled auto-ignition, operating range, homogeneous charge preparation, cold start and emissions of unburned hydro carbon (UHC), and carbon monoxide (CO) need to be overcome for successful operation of HCCI engine. Extensive research on HCCI combustion with a homogeneous fuel-air mixture preparation is going on throughout the world. This paper reviews the strategies of different external and in-cylinder mixture preparation methods which were adopted and proposed in the recent years. The different strategies of controlled auto-ignition by HCCI combustion are also discussed in this paper. [ABSTRACT FROM AUTHOR]

The construction sector is a key actor in fighting climate change. A clear and comprehensive accounting of its carbon emission responsibility is the basis for effective emission mitigation actions. The intersectoral and interregional trade of the construction sector complicates emission responsibility allocation. Neglecting such trade flows or measuring them from a single perspective may cause the sector's emission status to be misinterpreted. Hence, based on the environmentally extended multiregional input-output model, this paper establishes the construction sector's multiprinciple emission responsibility accounting framework and conducts multiple accounting for China's construction sector. The emission distribution and transfer across regions and sectors are systematically revealed, and various accounting principles, regional clusters, and corresponding policy implications are compared and discussed. The results show significant differences in the emission responsibilities of the construction sector under different principles, indicating that the choice of principles will greatly affect the determination of responsibility and corresponding policy priorities, which requires careful consideration. The emission responsibilities in different regions also have notable heterogeneity under each principle and are further clustered into three main emission patterns, suggesting that classified and targeted emission mitigation strategies should be adopted. The emission transfer analysis demonstrates that the construction sector is a typical end-of-chain sector with high emission-pulling effects on upstream industries and tiny emission-pushing effects on downstream industries, resulting in varied incentive impacts under each principle. Overall, this study contributes extensive insights into the emission responsibility of the construction sector, supporting common but differentiated emission reduction targets and policy settings. • A multiprinciple carbon accounting model for the construction sector is developed. • The emission distribution and transfer across regions and sectors are explored. • Accounting principles, emission patterns, and policy implications are compared. • Great disparities under various principles alert multiperspective strategy setting. • Regional heterogeneity in emissions emphasizes differentiated mitigation actions. [ABSTRACT FROM AUTHOR]

This paper presents a comprehensive taxonomy and assessment of existing and emerging space cooling technologies in Europe. The study aims to categorize 32 alternative space cooling technologies based on eight scouting parameters (physical energy form, basic working/operating principle, refrigerant or heat transfer medium, phase of the working fluid, specific physical process/device, type of space cooling technology, fuel type and technology readiness level) and evaluate their key characteristics and development trends. The increasing demand for space cooling in Europe necessitates a thorough understanding of these technologies and their potential for energy efficiency. The majority of space cooling demand in Europe is currently met by conventional vapour compression systems, while a small portion is covered by thermally-driven heat pumps. The study reveals that several alternative space cooling technologies show promise for energy-efficient cooling but are not yet competitive with vapour compression systems in terms of efficiency and cost in the short-term and medium-term. However, technologies such as membrane heat pumps, thermionic systems, thermotunnel systems, and evaporative liquid desiccant systems demonstrate cost-competitiveness and energy efficiency in specific applications. The findings highlight the need for further research and development to improve the efficiency, costs, and market competitiveness of alternative space cooling technologies. The study also emphasizes the importance of policy support and the urgency to reduce greenhouse gas emissions, which can drive the adoption and advancement of sustainable cooling solutions. • The study provides a taxonomy of 32 space cooling technologies in the EU • Eight scouting parameters are discussed to categorize the space cooling technologies • Most of the alternative technologies have potential but can't compete in efficiency and cost • Only ten of the alternative cooling technologies have a TRL between 5 and 9 • Membrane heat pumps, thermionic systems, thermotunnel systems, and evaporative liquid desiccant systems are cost-competitive and energy-efficient in certain applications. [ABSTRACT FROM AUTHOR]

The wastewater sector accounts for up to 7 and 10% of anthropogenic CH 4 and N 2 O emissions, respectively. Nowadays wastewater treatment plants are going through a paradigm shift to approach a net-zero carbon condition. Numerous ongoing measures have taken place to identify the sources of greenhouse gases and minimize the carbon footprint. This paper systematically reviews all known practices leading towards net-zero carbon wastewater treatment. The greenhouse gas emissions from the wastewater sector are identified and carbon footprint quantification tools, such as reliable models and emission factors are compared. The direct process emissions can contribute to over 60% of the carbon footprint in wastewater treatment plants, while around 30% of the carbon footprint is due to energy-related indirect emissions. Therefore, greenhouse gas mitigation via process optimization and energy usage in wastewater treatment plants are comprehensively described. The implantation of novel nitrogen removal processes can reduce both greenhouse gas emissions and energy consumption. Other techniques such as source separation systems can potentially allow mitigation of N 2 O emissions by 60% while avoiding energy-intensive nitrogen fertilizer production. Nutrient recovery methods are another approach which offer negative value for the net carbon footprint. Recovering N 2 O for energy production is a promising method which can lead to both direct and indirect carbon footprint reductions. Ultimately, to achieve full decarbonization any remaining emissions need to be offset, including carbon footprint of chemicals usage and transportation. [Display omitted] • Wastewater sector is going through a paradigm shift towards decarbonization • GHG emission hotspots are identified and emission factors are reviewed • WWTPs may be responsible for approximately 5% of total GHG emissions • Direct emissions can contribute to >60% of the carbon footprint in WWTPs • Process modifications and energy optimization play key roles towards net-zero WWTPs [ABSTRACT FROM AUTHOR]

Rapidly increasing catastrophic environmental incidents and changes in global climate have compelled researchers to take proactive measures for climate change mitigation. Consequently, reducing greenhouse gas emissions has become one of the most significant global targets. The transportation sector has a massive carbon footprint accounting for 22% of the total carbon dioxide emissions. In this regard, road transport contributes the largest fraction of the total emissions within the transportation sector. Conversely, the railway which is the cleanest form of transportation contributes slightly more than 1% of the total emissions. Moreover, since most of the rail systems are operated by government or private companies, it is relatively convenient to implement policies and replace conventional technology with environmentally friendly ones. This could be achieved by taking certain measures from technical and operational viewpoints for conserving energy to lower the carbon intensity of all transport modalities. Hence, this review paper focuses on investigating the railway sector to encourage a modal shift to the least carbon-intensive option. This study provides a critical review of the past and present rail technologies in terms of the environmental, economic, social, and technical perspectives. Moreover, a comparative assessment of the various locomotive types has been performed. The results reveal that battery-hydrogen hybrid locomotives are the best choice to be considered as a future locomotive technology. Hydrogen locomotives have the potential to be a promising alternative to diesel railway locomotives. However, certain technical barriers need to be overcome to enhance the overall system's performance and reliability to further improve the viability of its deployment in the railway sector. [Display omitted] • A critical review of the various rail technologies is provided through different viewpoints. • The assessment constitutes environmental, economic, social, and technical perspectives. • A decision-support tool for comparison of four rail technologies is also developed. • Battery-hydrogen hybrid locomotive results in the highest score of 1.47. • Standalone hydrogen locomotive results in the second highest score of 1.38. [ABSTRACT FROM AUTHOR]

Net-zero emission and self-sustaining carbon-neutral have been widely encouraged and intensively explored in wastewater treatment, as the wastewater industry accounts for approximately 1.6% of global greenhouse gas (GHG) emissions. However, how to achieve net-zero GHG emission in wastewater treatment from a biological standpoint is still lacking. In this paper, the status of GHG (i.e. nitrous oxide (N 2 O), methane (CH 4) and carbon dioxide (CO 2)) production and emission in wastewater treatment was comprehensively reviewed. Generally, N 2 O emission contributes the majority of the total GHG emissions from wastewater treatment, and the dissolved N 2 O and CH 4 in the effluent should be paid more attention for the further GHG mitigation. Based on the newly identified microbial communities capable of nitrogen removal with less GHG emissions, several alternative integration systems for GHG mitigation were discussed. Coupling denitrifying anaerobic methane oxidation with anammox process shows high nitrogen removal performance and low GHG emissions, which is regarded as a more promising integration system for GHG mitigation. Moreover, the novel strategies to manage N 2 O and CH 4 as energy sources were also demonstrated, aiming to offset certain carbon footprint in wastewater treatment and thus attain net-zero GHG emission. In addition, future challenges and perspectives of above integration systems and strategies were discussed to facilitate the development of environmentally sustainable wastewater treatment. Finally, a prospective hybrid system integrating emission reduction and energy recovery was proposed as an example for achieving net-zero GHG emission from wastewater treatment. [Display omitted] • Status on GHG production and emission in each treatment unit is quantified. • Autotrophic microorganisms play important roles in mitigating GHG emission. • CH 4 is more feasible than N 2 O for energy recovery from mainstream wastewater. • Net-zero GHG emission integrates both emission reduction and energy recovery. [ABSTRACT FROM AUTHOR]

The market of batteries for electric mobility is expected to greatly expand in Europe during the next decades. The most sustainable batteries to be produced in the future depend on the primary and secondary resources available and on the capacity to produce and recycle battery cells. This paper proposes an optimization model based on Material Flow Analysis and prospective Life Cycle Assessment which allows us to suggest the types of batteries which should be produced and recycled, the primary and secondary resources to be used, and in which quantities. Several scenarios are proposed to address the uncertainty of the future batteries market. In the Reference Scenario, designed to reflect the European policies, the results show that Europe would achieve high self-sufficiency from external producers (72%), but this percentage could decrease drastically in the case of alternative scenarios (up to 35%). Furthermore, in the Reference Scenario, lithium-iron-phosphates (40%) and lithium-air (23%) batteries result to be the best options. To cut the consumption of lithium and cobalt, sodium-ion cells (3%) could also be considered for manufacturing or even nickel-cobalt-manganese (6%) type to exploit secondary cobalt. In alternative scenarios instead, the proposed algorithm would suggest different choices as a function of the boundary conditions. For instance, in case the demand and the re-use rate of the cells are higher than in the Reference Scenario, the environmental impact of batteries for mobility turns out to increase because of the lower self-sufficiency of the European industry. • Material flow analysis and prospective LCA are integrated into an optimization model. • Several scenarios are set to address the uncertainty of the future batteries industry. • The European batteries' production and recycling to cut GHG emissions are assessed. • The optimal management of primary and secondary resources is evaluated in time. • The model evaluates the batteries industry's relevant GHG mitigation (up to −45%). [ABSTRACT FROM AUTHOR]

Improving energy performance has been recognized as an effective measure to promote the energy saving and emission reduction and to realize the sustainable development. Methods of improving energy performance towards sustainable manufacturing are numerous and scattered, resulting in insufficiency from the perspective of overall strategies and system integration. After the intensive selection of advanced literatures, about 166 research papers directly related to energy performance improvement are analyzed. A comprehensive review and analysis from multi-perspectives of energy monitoring, evaluation, optimization and benchmarking are performed, which is conducive to understand the energy consumption pattern and take effective energy-saving measures. This paper establishes a framework of energy performance integrated method, and four energy management methods and their energy models in energy monitoring, evaluation, optimization and benchmarking phase are analyzed and summarized. Besides, the proposed framework analyzes potential applications and key advantages, and some challenges and potential opportunities for energy performance improvement methods are discussed. This study will provide a significant foundation for energy-efficient production through various methods application. • Performing a review on methods of improving energy performance. • Constructing a framework of methods of improving energy performance. • Summarizing advances in energy monitoring, evaluation, optimization and benchmarking. • Discussing challenges and opportunities of improving energy performance. [ABSTRACT FROM AUTHOR]