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Abstract: Carbon paper is commonly used as the gas diffusion layer (GDL) in polymer electrolyte membrane (PEM) fuel cells as it exhibits high chemical and mechanical durability. This diffusion medium is also anisotropic, which directly affects its transport properties and specifically the thermal conductivity. In this study, the in-plane thermal conductivity of the carbon paper GDL was determined using thermal diffusivity measurements for a temperature range from −20 to +120°C and four Teflon loadings (0, 5, 20 and 50wt.%). It is important to understand the effect of temperature on the thermal conductivity since PEM fuel cells are designed to operate under various temperatures depending on the application of use. Further, Teflon is used to change the hydrophobic properties of the carbon paper GDL with 20wt.% as the most widely used percentage. In this study, the Teflon loadings were chosen to gain a comprehensive understanding of the thermal resistance due to Teflon. In this study, a quasi-steady method was used to measure the thermal properties of the carbon paper; hence, the phase transformation in the presence of PTFE was investigated. The thermal conductivity decreases with an increase in temperature for all samples. The addition of as little as 5wt.% Teflon resulted in high thermal resistance decreasing the overall thermal conductivity of the sample. Further addition of Teflon did not have major effects on the thermal conductivity. For all treated samples, the thermal conductivity lies in the range of 10.1–14.7W/mK. Finally, empirical relations for the thermal diffusivity and conductivity with temperature were deduced. [Copyright &y& Elsevier]

Highlights: • We consider the driving effect of green low-carbon behavior in our model. • We propose three green low-carbon behavior systems: GG, PG, PMG. • We get the growth welfare effect and the knowledge diffusion effect. Abstract This paper establishes a new endogenous growth model driven by green low-carbon behavior, optimizes the model and three systems with green low-carbon behavior in order to obtain the comprehensive effects of the empirical and policy of the three policies that have been set. This paper consists of three parts: green low-carbon behavior endogenous growth model, three green low-carbon behavior systems, empirical and policy effects. In the green low-carbon behavior endogenous growth model, we have built a new endogenous growth model, which is based on the existing endogenous growth model, considering the effects and influences of green low-carbon behavior. The model divides the economic system in green low-carbon behavior pattern into three modules: the production module, the household module and the R&D module. In the production module, we consider the number of knowledge diffusion in the intermediate goods and use the number of knowledge diffusion to explain the transmission of green low-carbon behavior. We consider environmental quality, capital, labor and emission input in the production function of the intermediate goods in a specific sector. Then we get the first-order conditions of intermediate producers based on the profit function of intermediate producers. In the household module, we consider consumption, environmental quality and carbon emissions in the representative household utility, and use Hamilton function in order to obtain the optimum conditions for the representative household with respect to consumption and physical capital. In the R&D module, we obtain the characteristics of the balanced growth path in a stable state. In the second part, we propose three green low-carbon behavior systems. Through the optimization of government budget, welfare function and the nine optimization solutions of the new model in green low-carbon behavior pattern, we compare the government's green low-carbon behavior (GG), private green low-carbon behavior motivated by the government (PMG) and private green low-carbon behavior motivated by anarchy (PG). Finally, we draw the conclusion that PMG is an optimal system to achieve the highest growth rate and welfare level. In the part of empirical and policy effects, we propose three green low-carbon parameters that policymakers need to consider and then the numerical simulations are conducted based on data from the United States and China. Then we compare the results obtained from the two countries' numerical simulation, and get the comprehensive effects of green low-carbon behavior: growth welfare effect and knowledge diffusion effect. [ABSTRACT FROM AUTHOR]

[Display omitted] • Robust low-carbon planning method is proposed for the SMGUS in steelmaking plant. • Decarbonizing steel plant through renewable energy, hydrogen, energy storage & CCUS. • Planning under different market conditions and CO 2 reduction routes are discussed. • Considering uncertainties promotes the deployment of flexibly adjustable equipment. • CCUS is the key for decarbonization of steel plant before massive use of renewables. Decarbonization of the steelmaking industry is imperative in achieving the carbon neutrality target. This paper proposes a two-stage low carbon robust planning method for the steel mill gas utilization system (SMGUS), which is the major CO 2 emission source of the conventional blast furnace route based-steelmaking plant. The planning aims to find the optimal installed capacities and relevant deployment time of multiple low-carbon technologies, such as renewable energy, energy storage, hydrogen energy and carbon capture & utilization, so that the demand of steel production can be met in an economically competitive and environmentally friendly way. Case studies are carried out on the low-carbon planning of a steelmaking plant with annual production of 1.5 million tons of crude steel, in which different carbon market conditions and CO 2 reduction routes are considered. The results show that the low carbon planning can reduce the CO 2 emissions to 1.22 tons per ton of steel by 2045–2050 through the proper deployment of the low carbon technologies. The CO 2 emissions can be further reduced to 0.31 tons per ton of steel if the BF-BOF process is replaced by H2-DRI and EAF technologies. This paper presents an effective planning method for the decarbonization of steelmaking plant. [ABSTRACT FROM AUTHOR]

• Lab synthesis of various adsorbents for adsorption-based PCC. • Bench and pilot-scale experimental studies of adsorption-based PCC. • Molecular simulation of adsorbents for post-combustion carbon capture. • Process modelling\simulation and techno-economic analysis of adsorption-based PCC. • Achievements, challenges and future prospect in adsorption-based PCC. Adsorption-based post-combustion carbon capture is a promising emerging technology for capturing CO 2 emissions from fossil-fueled power plants due to the ease of adsorbent regeneration in comparison with solvent-based technologies. To increase its competitiveness, research efforts have focused on the development of new adsorbent materials and processes. This paper presents a state-of-the-art review of such efforts, focusing on lab synthesis and characterization of adsorbent materials, (carbon capture) experimental studies, molecular simulation, process modelling\simulation and techno-economic analysis. Most experimental studies on adsorption-based post-combustion capture are at bench scale. Just a few experimental studies are at pilot scale. There are currently no commercial deployment of adsorption-based post-combustion capture technology. This review paper points out challenges encountered in these experimental investigations utilizing different adsorbent materials, limiting its commercial deployment. These gaps in experimental investigations need further research especially in the chemical modification of the adsorbent materials to increase the adsorption capacity. Molecular simulation of adsorbents and process modelling\simulation of carbon capture processes are cost-effective and time efficient approaches for the assessment of adsorbents' CO 2 capture performance. The review also highlighted the need for more research in the model development of adsorbent materials at molecular scale and the model development of adsorption-based post-combustion process adopting new reactor configurations to further reduce the cost of CO 2 capture. [ABSTRACT FROM AUTHOR]

As part of its energy transition strategy, China has set ambitious targets for increasing the contribution of renewable energy and, in particular, of wind power. However, the Chinese power sector has not undergone the necessary reforms to facilitate the integration and absorption of a larger share of variable renewable energy. This is evident from the difficulties in absorbing wind power from already commissioned wind farms and the resultant curtailment of wind power. Pumped storage hydroelectricity (PSH) is a flexible power source that can facilitate higher penetration levels of wind power as well as complement China’s growing nuclear power capacity. However, regulatory policy constraints have restricted the effective utilization of existing PSH capacity and discouraged investment in new PSH capacity. This paper examines these constraints and assesses the likely impact of new policies designed to address them. Finally, policy recommendations and concluding remarks are provided. This paper contributes to the literature on renewable energy integration from a new perspective. The lessons from China are relevant to other countries going through the energy transition. [ABSTRACT FROM AUTHOR]

This paper shows a new advanced control approach for operations in hybrid systems equipped with solid oxide fuel cell technology. This new tool, which combines feed-forward and standard proportional–integral techniques, controls the system during load changes avoiding failures and stress conditions detrimental to component life. This approach was selected to combine simplicity and good control performance. Moreover, the new approach presented in this paper eliminates the need for mass flow rate meters and other expensive probes, as usually required for a commercial plant. Compared to previous works, better performance is achieved in controlling fuel cell temperature (maximum gradient significantly lower than 3 K/min), reducing the pressure gap between cathode and anode sides (at least a 30% decrease during transient operations), and generating a higher safe margin (at least a 10% increase) for the Steam-to-Carbon Ratio. This new control system was developed and optimized using a hybrid system transient model implemented, validated and tested within previous works. The plant, comprising the coupling of a tubular solid oxide fuel cell stack with a microturbine, is equipped with a bypass valve able to connect the compressor outlet with the turbine inlet duct for rotational speed control. Following model development and tuning activities, several operative conditions were considered to show the new control system increased performance compared to previous tools (the same hybrid system model was used with the new control approach). Special attention was devoted to electrical load steps and ramps considering significant changes in ambient conditions. [ABSTRACT FROM AUTHOR]

Multiple geographically dispersed data center buildings have been increasingly positioned in renewable-rich areas due to their high energy consumption. This paper proposes an optimal multi-energy portfolio for zero carbon data center buildings in the presence of proactive demand response programs. In the data center buildings, the complementarities of hydro-solar-wind hybrid renewable energy sources (RESs) are fully exploited via multi-energy conversion and storage devices, which are modeled as 100% renewable energy hubs for zero carbon multi-energy supplies. In order to exploit the hub-internal operational dispatchability and flexibility, a comprehensive energy consumption model of data center buildings is proposed to facilitate the demand response in terms of available serves, while the variable speed pumped storage (VSPS) is modeled to capture its dynamic operational characteristics. The energy‑carbon production, conversion, storage, and consumption are formulated as an energy‑carbon matrix, which are solved via a two-stage method to obtain the optimal portfolio. Case studies on southwest China data center buildings are implemented to demonstrate the effectiveness and superiority of the proposed methodology on cost-effective accommodation of RESs. Simulations results show that the system portfolio cost can be reduced by at most 17.8% with a higher operational flexibility. • A cost-effective data center building is proposed to accommodate zero carbon targets. • Hydro-solar-wind 100% renewables are formulated for multi-energy supplies. • VSPS and data center energy consumption are modeled to exploit inherent flexibility. • The energy-carbon production, conversion, storage, and consumption are optimized. [ABSTRACT FROM AUTHOR]

• Presenting a set of mathematical models for green flowshop scheduling problems. • Considering common carbon reduction policies and their corresponding scenarios. • Providing analysis of models and insights to design a framework for green flowshops. • Industries can use our cost-effective strategies to meet limits mandated by government. • Government can explore our integrated framework to gauge impacts of carbon policies. In this paper we consider, from an environmental policy-maker perspective, how carbon reduction policies impact the economic competitiveness of the manufacturing sector. Specifically, we focus on flowshop scheduling – which typically aims to minimize makespan for purely economic objectives – and consider how three common carbon reduction policies – namely, taxes on emissions, baselines on emissions, and emissions trading schemes – can create competitive green flowshops that balance minimization of makespan and carbon emissions. The goal is to enable policy-makers to understand how to set policies and control parameters to achieve environmental objectives while ensuring global economic competitiveness of industry. We initially present a set of mixed-integer linear programming (MILP) models for flowshop scheduling problems operating in a regulated environment in which each carbon reduction policy is adopted. We then introduce a bi-objective scheduling framework for the corresponding problem to obtain alternative solutions under each policy. These models and their computational results however, are not the main focus of the study, but are presented as a means to demonstrate how green policies co-exist with economic objectives, with policy-makers in control of the balance. To this end, based on financial data from Australia's carbon emissions profile, we provide a policy-oriented analysis of the models, and some managerial insights into the effect of scheduling strategies on carbon emissions under different reduction policies. These insights offer support to both environmental policy-makers and corporate production and sustainability managers to determine whether it is technically feasible and profitable to replace traditional scheduling strategies with environmentally friendly scheduling strategies. [ABSTRACT FROM AUTHOR]

• The first 2D combined CH4-assisted SOEC and F-T synthesis model is developed. • A novel strategy towards low-carbon fuel generation is proposed. • Parametric studies are conducted with performance determining factors discussed. • The distribution of generated carbon-contained fuels (from C 1 to C 5+) is studied. CH 4 -assisted solid oxide electrolyzer cells (SOECs) can co-electrolyze H 2 O and CO 2 effectively for simultaneous energy storage and CO 2 utilization. Compared with conventional SOECs, CH 4 -assisted SOECs consume less electricity because CH 4 in the anode provides part of the energy for electrolysis. As syngas (CO and H 2 mixture) is generated from the co-electrolysis process, it is necessary to study its utilization through the subsequent processes, such as Fischer-Tropsch (F-T) synthesis to produce more value-added products. An F-T reactor can convert syngas into hydrocarbons, and thus it is very suitable for the utilization of syngas. In this paper, the combined CH 4 -assisted SOEC and F-T synthesis system is numerically studied. Validated 2D models for CH 4 -assisted SOEC and F-T processes are adopted for parametric studies. It is found that the cathode inlet H 2 O/CO 2 ratio in the SOEC significantly affects the production components through the F-T process. Other operating parameters such as the operating temperature and applied voltage of the SOEC are found to greatly affect the productions of the system. This model is important for understanding and design optimization of the combined fuel-assisted SOEC and F-T synthesis system to achieve economical hydrocarbon generation. [ABSTRACT FROM AUTHOR]

• A high spatial resolution CO 2 emissions inventory of 280 Chinese cities was compiled. • Three methods were compared to evaluate the carbon efficiency of Chinese cities. • The best and worst-performing cities were consistent regardless of different methods. • Top-ranking cities were located in the coastal regions of China. • Lagging-behind cities were located in the central and western regions of China. Comprehensive and accurate city-level carbon dioxide emissions inventory is key to success in China's pursuit of low-carbon development. Based on a high-resolution gridded data, this paper evaluates and benchmarks the carbon emissions efficiency of 280 Chinese cities using three different methods, i.e., composite index, data envelopment analysis and stochastic frontier analysis. The comparative analysis reveals that the average carbon emissions efficiency of Chinese cities is about 70–90%, with only 9 efficient cities (3%). Although the ranking of intermediate cities varies greatly according to the method employed, the most and least carbon-efficient cities remain consistent. While the best-performing cities are found in the coastal regions, the worst-performing cities are located in the central and western regions, which suggests an imbalanced low-carbon development in China. Guided by the results, local governments are encouraged to compete and learn from similar ranking benchmarks in a new regime of "Top Runner City". Finally, the scores of carbon emissions efficiency can provide a scientific basis for the bottom-up allocation of carbon emissions rights to boost the development of the nationwide carbon market in China. [ABSTRACT FROM AUTHOR]

Graphical abstract Highlights • We incorporate a variety of principles and indicators into an improved ZSG-DEA model. • We conduct a multi-criteria allocation of China's CEA by 2030 to provincial shares. • We measure the total and per capita space for carbon emissions by province. • All provinces reach the DEA frontier with different CEA ranging from 4.21 to 16.77 Gt. • Differentiated provincial reduction policies are the key to achieving China's INDCs. Abstract Accelerating global warming has suggested the importance of controlling greenhouse gas emissions associated with human activities. In striving to fulfill the Paris Agreement, China has announced its Intended Nationally Determined Contributions (INDCs) aimed at reducing its carbon dioxide (CO 2) emission intensity by 60–65% in 2030 against the level of 2005. However, China's INDCs cannot be fulfilled without formulating appropriate schemes for the allocation of carbon emission allowance (CEA) at sub-national scales. To help close the gap in our knowledge, this paper starts with measuring the overall CEA of China by 2030, and then proposes a science-based scheme for CEA allocation by developing an improved zero sum gains-data envelopment analysis (ZSG-DEA) model. It demonstrates that the final CEA of some northern provinces can be cut down as compared to their initial shares and, conversely, most southern provinces experience an increase in their CEA. Comparing the final share of CEA by province with current carbon emissions, we observe that provinces with abundant energy reserves, such as Shanxi, Inner Mongolia and Shaanxi, tend to be operating in a state of overshoot in terms of space for carbon emissions (SCE). In contrast, there remains SCE when it comes to Guangdong, Hunan, Fujian, etc. The remaining provinces, such as Heilongjiang, Hebei and Ningxia, are close to the break-even point. In view of the differing SCE of individual provinces, common but differentiated policies for CO 2 emission control would be the key to achieving China's INDCs. The research findings lay a scientific basis for the Chinese government to make its INDCs come true through inter-provincial collaboration on emission reduction, but also serve as a reference for fueling further scientific discussions and development of schemes for the allocation of responsibility for carbon emissions at multiple scales within and beyond China. [ABSTRACT FROM AUTHOR]

Highlights • A stochastic programming approach is proposed to model TS and ESS sizing simultaneously. • The model considers DSM and renewable energy curtailment policies with various limits. • The effect of TS on total cost, sizes, locations of ESS are discussed. • We find that TS is noteworthy to analyze for power systems with renewable targets. Abstract Increasing the share of renewable energy sources in electricity generation helps address concerns about carbon emissions, global warming and energy security (i.e. dependence on fossil fuels). However, integrating intermittent and variable energy sources into the grid imposes new challenges for power system reliability and stability. To use these clean sources in electricity generation without endangering power systems, utilities can implement various control mechanisms, such as energy storage systems, demand side management, renewable energy curtailment and transmission switching. This paper introduces a two-stage stochastic programming model that co-optimizes transmission switching operations, and transmission and storage investments subject to limitations on load shedding and curtailment amounts. We discuss the effect of transmission switching on the total investment and operational costs, siting and sizing decisions of energy storage systems, and load shedding and renewable energy curtailment in a power system with high renewable penetration. An extensive computational study on the IEEE 24-bus power system with wind and solar as available renewable sources demonstrates that the total cost and total capacity of energy storage systems can be decreased up to 17% and 50%, respectively, when transmission switching is incorporated into the power system. [ABSTRACT FROM AUTHOR]

Highlights • The flexible resources for integrating wind power are analyzed from the cost perspective. • The balancing cost when using coal-fired generation could reach $4/MWhw. • The cost of DSM for integrating wind power can be very low. • The EES will prevail coal-fired generation when its capital cost drops below 400$/kWh. Abstract The inherent stochastic nature of wind power requires additional flexibility during power system operation. Traditionally, conventional generation is the only option to provide the required flexibility. However, the provision of the flexibility from the conventional generation such as coal-fired generating units comes at the cost of significantly additional fuel consumption and carbon emissions. Fortunately, with the development of the technologies, energy storage and customer demand response would be able to compete with the conventional generation in providing the flexibility. Give that power systems should deploy the most economic resources for provision of the required operational flexibility, this paper presents a detailed analysis of the economic characteristics of these key flexibility options. The concept of “balancing cost” is proposed to represent the cost of utilizing the flexible resources to integrate the variable wind power. The key indicators are proposed respectively for the different flexible resources to measure the balancing cost. Moreover, the optimization models are developed to evaluate the indicators to find out the balancing costs when utilizing different flexible resources. The results illustrate that exploiting the potential of flexibility from demand side management is the preferred option for integrating variable wind power when the penetration level is below 10%, preventing additional fuel consumption and carbon emissions. However, it may require 8% of the customer demand to be flexible and available. Moreover, although energy storage is currently relatively expensive, it is likely to prevail over conventional generation by 2025 to 2030, when the capital cost of energy storage is projected to drop to approximately $400/kWh or lower. [ABSTRACT FROM AUTHOR]

Abstract: This study examines the economics of energy-efficiency strategies, for reducing CO2 emissions in a residential sector in Japan, from the perspective of regional characteristics. For this study, the residential sector in the Iwate prefecture was selected as representative of rural areas in Japan. In order to promote the purchases of energy-efficient consumer appliances, the prefectural government is presumed to reimburse purchasers a part of the cost difference between energy-efficient and conventional appliances. This paper begins with a discussion of the prefecture’s financial support for purchasers of energy-efficient appliances and assumes that the payments come from prefectural government funds. This paper then looks at the effect of a carbon-tax refund on the reduction of CO2 emissions. The results show that, if half of the households use energy-efficient appliances, then CO2 emissions in the residential sector in the year 2020 will decreases from the BAU scenario of 0.726Mt-C to 0.674Mt-C. However, the Iwate prefectural government expends $105 million annually, which is 1.5% of the total tax revenue for the year 2003. The carbon-tax refund effectively encourages further reductions in CO2 emissions. Under the $20/tC carbon-tax, proposed by the Ministry of the Environment, the carbon-tax refund leads to a reduction in residential CO2 emissions from 0.726Mt-C to 0.712Mt-C. [Copyright &y& Elsevier]

China’s commitment to the UNFCCC to peak its emissions by 2030, or sooner, signaled a long anticipated shift in China’s model of development with far reaching consequences. Cities in China, and particularly the residential sector in cities, will be charged with making significant reductions in emissions growth even as rates of urbanization continue to climb. Focusing on Beijing and Shanghai, this paper carries out a measures-based economic analysis of low carbon investment opportunities in the residential sector. Results find significant opportunity: between 2015 and 2030, BAU levels of CO 2 emissions could be reduced by 10.2% in Beijing and 6.8% in Shanghai with the adoption of economically attractive low carbon measures. While these headline results underline the case for low carbon investment in the residential sectors of these megacities in China, a closer analysis provides insights for understanding the economics of decarbonisation in cities more generally. [ABSTRACT FROM AUTHOR]

• Shrinking cities tend to be less energy efficient than their growing counterparts. • Shrinking cities need to consider the environmental effects of shrinkage. • Urban compactness is negatively associated with residential CO 2 emissions. • Intra-city polycentricity is negatively correlated with gas-related CO 2 emissions. This paper analyzes the relationship between urban form, shrinking cities, and residential carbon emissions, based on information collected for prefectural-level and above Chinese cities for the years of 2005, 2010, and 2015. After controlling for a number of urban form and socioeconomic variables (e.g., size, compactness, and polycentricity), this paper pays attention to residential carbon emissions in 'shrinking cities', which have experienced population loss and are a recent urban phenomenon in China. Everything else being equal, shrinking cities tend to be associated with less energy efficient than their growing counterparts, suggesting that these cities may not only be 'battling' with shrinking populations and economies but also need to consider the environmental issues. [ABSTRACT FROM AUTHOR]

• The average carbon reduction performance increases year by year. • The policy has an immediate impact on CO 2 reduction in demonstration cities. • The policy has follow-up impact on carbon emission reduction. • Less thermal power and more research investment are the paths to policy effect. The Energy-saving and Emission Reduction Demonstration City (ESERD) Policy brings more favorable development conditions and opportunities for the cities selected, but the carbon reduction effect of the energy-saving policy is not clear which needs to be quantified and evaluated. By measuring the Total Factor/Energy Carbon Performance Index (TCPI /ECPI) of 286 prefecture-level cities in China from 2003 to 2019 and by constructing a quasi-natural experiment, this paper contributes in three aspects. (1) we are committed to a method of calculating the energy consumption and carbon emission of prefecture-level cities in China; (2) we provide evidence to the CO 2 reduction effect of the ESERD policy in a more comprehensive way; (3) we probe the paths of the policy effects. The main findings are: (1) TCPI and ECPI has been rising since 2011, the eastern cities have more outstanding achievement while the performance of the western region has been at a relatively high level during the time period of the study, and the performance of cities have diverged in recent years. (2) The policy's contribution to the demonstration cities' carbon reduction performance is significant, immediate and far-reaching, a lower share of electricity consumption due to indirectly reducing the use of coal, and higher investment in scientific research for improving the technology level of industrial development are both paths to achieve carbon emission reduction in the demonstration cities. [ABSTRACT FROM AUTHOR]

Direct carbon solid oxide fuel cell (DC-SOFC) is a promising energy conversion device for power generation using solid carbon fuel. In this paper, a 2D model is developed for a tubular DC-SOFC for CO and electricity co-generation. Parametric simulations are conducted to understand the physical/chemical processes in the DC-SOFC. Good performance of DC-SOFC is observed even at a large distance between the carbon bed and the porous anode, indicating the feasibility of large-scale DC-SOFC applications. The DC-SOFC performance is found to decrease with decreasing temperature due to the decreased Boudouard reaction kinetics. It’s also found that the molar fraction of CO at the anode can be well controlled by adjusting the operating conditions, enabling DC-SOFC for electricity and CO cogeneration. Another finding is that the current density in the DC-SOFC increases slightly along the cell length, which is different from the H 2 -fueled SOFC. In addition, the anode-supported configuration is found to be beneficial in improving the electrical output of the DC-SOFC but is unfavorable for CO generation. A small D ce and a high potential are recommended to improve CO generation from the DC-SOFC. The model can be used for design optimization of DC-SOFC at a system level. [ABSTRACT FROM AUTHOR]

Lithium-ion storage capacitors were assembled using graphene/tantalum carbide/tantalum wire electrodes and carbon hollow spheres as electrolyte. The graphene/tantalum carbide layers were prepared by electron-assisted hot filament chemical vapor deposition; the carbon hollow spheres were synthesized by hydrothermal reaction and pyrolysis treatment. The specific capacitance of the capacitor was 593 F g −1 at a current density of 10 A g −1 . The capacitor showed excellent cycling stability, retaining 91.2% of its initial capacitance after 8000 cycles. Moreover, the capacitor provided a high specific energy density of 132 W h kg −1 at a high power density of 3.17 kW kg −1 . The high energy density is attributed to the widened operation window ranging from 0 to 3.0 V. The graphene layer of the electrode and carbon hollow spheres in electrolyte synergistic affect influence on the electrochemical performance of the capacitor are discussed. In addition, the use of a low-cost lithium salt, lithium chloride, is also featured in this paper. [ABSTRACT FROM AUTHOR]

Climate change present a range of equity issues for human being, but operating the equity principle within emission allocation scheme to various parties has raised multiple challenges. Although more than 40 schemes have been suggested in the literatures, there is little consistency in the way that baselines, scope, coverage and other key parameters have been compared or discussed. In this paper, we reviewed 41 schemes used in the literature so far and compared the cumulative allowances of main countries under various schemes in a consistent framework. Two cases are considered, i.e. only energy and industry related CO 2 and all Kyoto GHGs. Besides the allowances, carbon Gini coefficient in the global perspective and the reduction tradeoffs between country groups are further quantitatively discussed. It is demonstrated that the full ranges of countries’ allowances are quite large resulting from different equity considerations and implement methods behind different effort-sharing schemes. However, absolute mitigations are always required in developed countries in order to realize the 2 °C target, regardless of schemes. [ABSTRACT FROM AUTHOR]

The prioritized purpose of this dissertation is to put forward a scientific and plausible interval of carbon price benchmark on the unified carbon trading market, of which will be scheduled to be established in the year of 2016. A model named EMD–GARCH that integrated Empirical Mode Decomposition (EMD) with Generalized Autoregressive Conditionally Heteroskedastic (GARCH) together is presented here in order to forecast the carbon price of the five pilots (Shenzhen, Shanghai, Beijing, Guangdong, and Tianjin) in 2016 so as to provide exogenous data for later analysis. For further study, a recursive dynamic Computable General Equilibrium (CGE) model will be structured to explore the impacts on China’s macroeconomics, environmental quality, and energy demand respectively under 8 different simulation scenarios, which are being designed in terms of the aforementioned calculated carbon price outcome. The simulation results illustrate that the unified carbon price policy will exert a comprehensive effect on China in various perspectives that we discussed in this paper. Moreover, regarding the carbon price scenarios, the price level by itself generates a different degree of impacts in improving the environmental quality, decreasing the energy demand, and increasing the macroeconomic growth. Consequently, based on the analysis of those three approaches mix in this study, we suggest the alternative interval of carbon price benchmark in the national unified carbon trading market with a lower bound of 30 yuan/tCO 2 to an upper bound of 50 yuan/tCO 2 . [ABSTRACT FROM AUTHOR]

This paper provides a review on three streams of life cycle studies that have been frequently applied to evaluate the environmental impacts of building construction with a major focus on whether they can be used for decision making. The three streams are Life Cycle Assessment (LCA), Life Cycle Energy Assessment (LCEA) and Life Cycle Carbon Emissions Assessment (LCCO 2 A). They were compared against their evaluation objectives, methodologies, and findings. Although they share similar objectives in evaluating the environmental impacts over the life cycle of building construction, they show some differences in the major focuses of evaluation and methodologies employed. Generally, it has been revealed that quite consistent results can be derived from the three streams with regard to the relative contribution of different phases of life cycle. However, discrepancies occur among the findings obtained from the three streams when different compositions of fuel mixes are used in power generation, or when the overall impacts are not contributed mostly by greenhouse gases emissions. The use of different functional units in different studies also makes it difficult to compare results with benchmarks or results from previous studies. Besides, there are drawbacks in boundary scoping, methodology framework, data inventory and practices which impair their usefulness as a decision making support tool for sustainable building designs. [ABSTRACT FROM AUTHOR]

Eco-innovations are being recognized as fundamental means to foster sustainable development, as well as to create new business opportunities. Nowadays, the eco-innovation concept is gaining ground within both academic and practitioner studies with the attempt to better understand the main dynamics underlying its nature and guide policymakers and companies in supporting its development. This paper contributes to the extant literature on eco-innovation by providing a comprehensive overview of the evolution of a specific type of eco-innovations that are playing a crucial role in the current socio-economic agenda, namely low-carbon energy technologies. Accordingly, we focus our attention on the related patenting activity of different countries and organizations over time, as well as on influencing policy initiatives and events. Hence, we collected 131,661 patents granted at the United States Patent and Trademark Office (U.S.PTO.) between 1971 and 2010, and belonging to the “Nuclear power generation”, “Alternative energy production”, and “Energy conservation” technological classes, as indicated by the International Patent Classification (IPC) Green Inventory. Our findings report the development trends of low-carbon energy technologies, as well as identify major related environmental programs, historical events, and private sector initiatives explaining those trends, hence revealing how these different circumstances have significantly influenced their development over time. [ABSTRACT FROM AUTHOR]

• A multi-regional input–output model is applied for empirical analysis. • Relationships between rebound effects and consumption patterns are investigated. • The rebound risks are measured from three perspectives. • Repressing the direct rebound effect can counteract the total rebound effect. Improving energy efficiency is considered to be essential to carbon emission reduction. However, it may not be as effective as expected due to the rebound effect. This paper attempts to investigate the carbon rebound effects and rebound risks in households. For this purpose, a comprehensive analysis framework incorporating elastic estimates, environmentally extended multi-regional input–output model and re-spending model, were built. Three rebound risk indicators were then constructed, following which a simulation of direct and indirect carbon rebound effects was conducted for urban households in China. By comparing the estimation results of the four re-spending scenarios, we found these households' carbon rebound effect to be significant. The empirical results further indicate significant differences in the rebound risk among different provinces. Overall, Xinjiang, Qinghai and Ningxia are the provinces most vulnerable to the rebound effect. These findings point to the necessity of the government adopting other measures besides energy efficiency policies, with regional differences taken into account, in order to curb the carbon rebound effect. [ABSTRACT FROM AUTHOR]

Highlights: [•] This paper discusses about a methodology on the life cycle analysis of power generation using nuclear as an example. [•] The methodology encompasses generic system, input–output, and boundaries definitions. [•] The boundaries facilitate the use of Kaya Identity and decomposition technique to identify carbon emission streams. [ABSTRACT FROM AUTHOR]

Highlights: [•] Improved power generation of MFC with Au nanoparticles modified carbon paper. [•] Coulombic efficiency increased with Au nanoparticle density. [•] Different Au nanoparticles densities resulted in different microbial communities. [•] More diverse bacterial communities with higher Au nanoparticle densities. [ABSTRACT FROM AUTHOR]

Carbon emission allowances are issued to limit the carbon emission by enterprises, but some unforeseen variables may cause their demand unpredictable. Together with the high volatility of carbon price dynamic, management of carbon asset is of great significance and difficulty for those enterprises with heavy carbon consumption. To cope with the demand and price uncertainty of carbon emission right, carbon derivative provides a feasible solution for those enterprises. This paper proposes applying the carbon option for carbon management. For better applying this tool, carbon option is evaluated through a geometric Brownian motion model with regime-switching. Based on the value estimation and analysis of carbon option, decision making and strategy design for carbon asset management are achieved by the quantitative results of option pricing and digital detection during the operation. Development of the modeling and algorithm for carbon option pricing is the main theoretical contribution, also it enriches the theory of real option property of carbon. Moreover, it provides a detailed schema and an inspiring case study of applying the options for carbon asset management and facilitating the decision-making digitally in line with the market information constantly updated, and it is applicable and believed to optimize the risk control for all enterprises with carbon-consumption. • Carbon option is priced and applied for digital decision-making of the transactions. [ABSTRACT FROM AUTHOR]

• The first to examine the herding behavior in China's eight carbon markets. • Beijing, Shanghai, Chongqing, Fujian four carbon markets exist herding behavior. • There is no herding behavior in China's overall carbon market. • Herding intensity is positively correlated with carbon market volatility. This paper introduces a modified cross-sectional absolute deviation approach to measure the existence of herding behavior and herding asymmetry, and uses the runs test to measure the herding intensity in China's carbon markets. It is the first study to examine the existence of herding behavior in China's carbon markets. The empirical results show that no herding behavior exists in China's overall carbon market. As for herding asymmetry, no herding behavior exists in both up and down markets and in the markets with high and low trading volumes, as well as in the markets with high volatility. Among China's eight carbon markets, herding behavior exists in Beijing, Shanghai, Chongqing, and Fujian, in which Chongqing has the highest herding intensity, while Guangdong, Hubei, Shenzhen, and Tianjin have no herding behavior. The herding behavior is prone to the occurrence when carbon price continuously rises or falls with high volatility. When the carbon market is highly volatile with a large transaction volume, the herding intensity is high. Herding intensity is positively correlated with market volatility. Finally, we propose policy implications to mitigate herding behavior. [ABSTRACT FROM AUTHOR]

Abstract: This paper investigates whether coal-fired Integrated Gasification Combined-Cycle (IGCC) power plants can be an economically viable future technology for providing less carbon-intensive electricity and heat energy in Germany than today. In the context of CO2 emission mitigation in power generation, energy conversion technologies enabling the implementation of Carbon Capture and Storage (CCS) need to be considered. IGCC is such a technology, as it utilizes coal but does not necessarily emit CO2. In our study we investigate, from an economic perspective, whether IGCC plants can be an alternative to nuclear and/or conventional coal-fired power plants. The research is based on scenario analysis. The starting point is the expected shut-down of nuclear power stations and outdated coal-fired power plants, as well as the projected evolution of the CO2 price. The hot gas cleaning option in IGCC plants is of particular interest, as it allows a significant enhancement of the efficiency of the IGCC technology and the use of combined heat and power production (CHP). Corresponding supplementary earnings (incl. subsidies) are compared with an increase in specific investment costs. Besides hot gas cleaning, we also investigate the economic impact of injecting pure CO2 (separated from the IGCC process) into oilfields, as Enhanced Oil Recovery (EOR) can help to reduce the costs of CO2 transport and storage. Based on the results from our analysis we find that the replacement of currently operating power plants by IGCC facilities is only reasonable under certain circumstances, e.g. for locational reasons. Furthermore, from today’s perspective, and due to its various advantages, a complete abandonment of the IGCC technology seems rather unlikely. Our analysis of NPVs of total costs indicates that some IGCC designs exist that are less expensive to set up and operate than a conventional reference power plant. The option of injecting CO2 sequestered from the power plant process into almost depleted oil fields appears attractive for a utility investing in IGCC technology, rendering such a plant configuration as likely cost-competitive. However, with regard to climate change mitigation, the least-cost investment alternative is not necessarily the one with the lowest GHG emissions. Significant cost reductions can be achieved by improving the efficiency or the availability of the plant. Finally, the NPV changes markedly when the heat-to-power ratio is altered, and high ratios are found to be incompatible with NPV minimization. [Copyright &y& Elsevier]

Abstract: The presence of price clustering in markets is taken as a sign of market inefficiency that can influence trading strategies. In this paper, we study the presence of a concentration in prices in carbon futures markets. Specifically, we analyze the European Carbon Futures Markets and test for evidence of preference for certain prices above others. Our results reveal the strong presence of price clustering in the carbon market at prices ending in digits 0 and 5. These findings support the attraction hypothesis, which endorses a significant clustering on gravitational prices, but also backs the negotiation hypothesis, which advocates greater clustering when trading costs are higher. [Copyright &y& Elsevier]

Abstract: Sensitivity analysis is a technique that evaluates the model response to changes in input assumptions. Due to uncertain prices of primary fuels in the world market, Government regulations for sustainability and various other technical parameters there is a need to analyze the techno-economic parameters which play an important role in policy formulations. This paper examines the variations in technical as well as economic parameters that can mostly affect the energy policy of India. MARKAL energy simulation model has been used to analyze the uncertainty in all techno-economic parameters. Various ranges of input parameters are adopted from previous studies. The results show that at lower discount rate coal is the least preferred technology and correspondingly carbon emission reduction. With increased gas and nuclear fuel prices they disappear from the allocations of energy mix. [Copyright &y& Elsevier]

Abstract: This paper examines carbon price volatility using data from the European Union Emission Trading Scheme from a nonlinear dynamics point of view. First, we use a random walk model, including serial correlation and variance ratio tests, to determine whether carbon price history information is fully reflected in current carbon price. The empirical research results show that carbon price is not a random walk: the price history information is not fully reflected in current carbon price. Second, use R/S, modified R/S and ARFIMA to analyse the memory of carbon price history. For the period April 2005–December 2008, the modified Hurst index of the carbon price is 0.4859 and the d value of ARFIMA is −0.1191, indicating short-term memory of the carbon price. Third, we use chaos theory to analyse the influence of the carbon market internal mechanism on carbon price, i.e., the market’s positive and negative feedback mechanism and the heterogeneous environment. Chaos theory proves that the correlation dimension of carbon price increases. The maximal Lyapunov exponent is positive and large. There is no obvious complex endogenous phenomenon of nonlinear dynamics the carbon price fluctuation. The carbon market is mildly chaotic, showing both market and fractal market characteristics. Price fluctuation is not only influenced by the internal market mechanism, but is also impacted by the heterogeneous environment. Finally, we provide suggestions for regulation and development of carbon market. [Copyright &y& Elsevier]

Abstract: Carbon Emissions Pinch Analysis (CEPA) is a recent extension of traditional thermal and mass pinch analysis to the area of emissions targeting and planning on a macro-scale (i.e. economy wide). This paper presents an extension to the current methodology that accounts for increased demand and a carbon pinch analysis of the New Zealand electricity industry while illustrating some of the issues with realising meaningful emissions reductions. The current large proportion of renewable generation (67% in 2007) complicates extensive reduction of carbon emissions from electricity generation. The largest growth in renewable generation is expected to come from geothermal generation followed by wind and hydro. A four fold increase in geothermal generation capacity is needed in addition to large amounts of new wind generation to reduce emissions to around 1990 levels and also meet projected demand. The expected expansion of geothermal generation in New Zealand raises issues of GHG emissions from the geothermal fields. The emissions factors between fields can vary by almost two orders of magnitude making predictions of total emissions highly site specific. [Copyright &y& Elsevier]

Abstract: Recent studies indicate carbon dioxide (R744) as a valid alternative to classical substances such as HFCs used in vapour compression plants. However a transcritical refrigeration cycle is needed because the critical temperature of carbon dioxide is usually near the ambient temperature. Consequently the carbon dioxide refrigerator performances are significantly influenced by the heat rejection pressure. In this paper an experimental investigation on working optimization for a “split-system” to cool air in residential applications is presented: by varying the heat rejection pressure an optimum working condition has been found at different ambient temperatures. Furthermore a simplified model to predict the optimum heat rejection pressure is shown and a comparison with experimental results is carried out. Both the model validation and the experimental results suggest that the heat rejection pressure optimization is an convenient method to improve the performance of a carbon dioxide split system. Finally an algorithm based on the aforementioned model has been proposed in order to control an electronic back pressure valve by means of a PLC. [Copyright &y& Elsevier]

Abstract: The UK government’s economy-wide 60% carbon dioxide reduction target by 2050 requires a paradigm shift in the whole energy system. Numerous analytical studies have concluded that the power sector is a critical contributor to a low carbon energy system, and electricity generation has dominated the policy discussion on UK decarbonisation scenarios. However, range of technical, social and market challenges, combined with alternate market investment strategies mean that large scale deployment of key classes of low carbon electricity technologies is fraught with uncertainty. The UK MARKAL energy systems model has been used to investigate these long-term uncertainties in key electricity generation options. A range of power sector specific parametric sensitivities have been performed under a ‘what-if’ framework to provide a systematic exploration of least-cost energy system configurations under a broad, integrated set of input assumptions. In this paper results of six sensitivities, via restricted investments in key low carbon technologies to reflect their technical and political uncertainties, and an alternate investment strategies from perceived risk and other barriers, have been presented. [Copyright &y& Elsevier]

Abstract: The clean development mechanism (CDM) has the objective to support developing countries in achieving a sustainable development path, while at the same time assisting industrialized countries in achieving their Kyoto Protocol commitments. Actual practice shows that CDM technology transfers are largely focused on reducing GHG emissions at lowest cost and less on the domestic development needs and priorities of the host countries. This paper discusses an approach to facilitate low-carbon energy technology transfer compatible with the energy development needs and priorities of developing countries. The results reported here are concerned with the relation between the transfer of low-carbon energy technologies and the perceived needs and priorities for low-carbon technologies in the country context. The study has provided insights on improving the CDM for technology transfer in accordance with host countries’ development priorities and has been applied to Chile, China, Israel, Kenya and Thailand. It forms the first stage of an overall approach for facilitating low-carbon technology transfer under the UNFCCC. The second stage of the study is reported elsewhere [ENTTRANS, 2008. Promoting sustainable energy technology transfers through the CDM: Converting from a theoretical concept to practical action. Final report of specific support action under EU FP-6, January 2006–December 2007. Contract 022673, co-ordination: Foundation JIN, Groningen, The Netherlands, www.enttrans.org]. [Copyright &y& Elsevier]