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The bioeconomy model provides an alternative view of global economic systems by putting sustainable practices combined with digital approaches at the forefront to tackle issues such as climate change. To address this new business trends, financial institutions began to set up the environmental, social, and governance (ESG) business units to evaluate their business strategies. This paper is aimed at examining the nonfinancial effect created by the digital transformation (DT) activities, highlighting the role of enterprise heterogeneity after the implementation of Environmental Protection Law (EPL) in China. We employ the panel data of A-share listed companies from 2010 to 2020, selecting DT and ESG indicators as the important representations of "Industry 5.0." Our empirical results demonstrate a positive impact of EPL on the ESG performance in sight of resource enterprises (REs), environmental enterprises (EEs), and polluting enterprises (PEs), but a negative impact of EPL on the DT indicators among those environmental related industries. Additional causal relationship regression reveals that enterprise DT has an intrinsic promoting effect on the ESG performance, emphasizing on the high risk of digitization process being the shock transmitters to enterprise nonfinancial indices. Notably, the connectedness of environmental policy illustrates dynamic patterns by parallel trend test and propensity score matching (PSM) DID regression. This paper is prone to benefit lawmakers, regulators, and firm executives responsible for analyzing and assessing enterprise digitization behavior by exploring the influence of macrolevel environmental policy. [ABSTRACT FROM AUTHOR]

China's renewable energy products have an important place in international trade, and the conclusion of the RCEP agreement can create favourable external conditions for China's renewable energy product exports. This paper measures the export potential of China's renewable energy products to other RCEP countries through a trade gravity model. The results show that (1) the GDP of the importing and exporting countries, the energy consumption of the importing countries, and the particulate emissions damage significantly enhance China's renewable energy product exports; (2) among the RCEP countries, China has a greater potential to export renewable energy products to five countries in 2020, which are mainly located in East and Southeast Asia; and (3) from a dynamic perspective, China's renewable energy trade potential is increasing, while in the Oceania region it is weakening, while trade links to Southeast Asian countries are developing in a more mature direction. Based on the above research, this paper puts forward corresponding policy recommendations. [ABSTRACT FROM AUTHOR]

In order to evaluate the effect of market-oriented environmental management measures on regional carbon emission intensity in the pilot areas better, this paper adopts a quasinatural experiment of energy-use rights trading (EURT) policy by using the difference-in-difference method from the perspective of cities in China from 2006 to 2019. The results show that the policy of EURT can significantly reduce regional carbon emission intensity, which varies in different regions and different scales of cities. The main goal of implementing the policy is to reduce regional carbon emission intensity by improving the energy consumption structure and promoting the improvement of industrial structure and green innovation. In addition, the spatial impact of the EURT pilot project is demonstrated by its ability to not only reduce local carbon emission intensity but also decrease carbon intensity in and around the designated areas. [ABSTRACT FROM AUTHOR]

In recent years, the Chinese Central Government has put great emphasis on the marine economy, since it has been a new driving force of the national economic development. Yet, the relationship between marine economic development and energy efficiency remains unknown. In this paper, we investigate whether marine economic development affected energy efficiency. We focused on the Zhoushan Archipelago, the first National New Area for marine economic development in China. We applied panel data approach to construct the counterfactual of Zhoushan Archipelago. We compared Zhoushan and its counterfactual, the synthetic Zhoushan, and viewed the difference between them, after the Zhoushan Archipelago New Area, as the impact of marine economic development on energy efficiency. We found that compared with its counterfactual, the real Zhoushan had a more substantial improvement in energy efficiency after the National New Area construction. We estimated that the construction of the National New Area for Marine Economy increased energy efficiency by about 10 percentage points. We also applied the bootstrapping technique to illustrate the significance of the estimated results. The results suggest that the Zhoushan Archipelago New Area construction had a statistically significant impact on energy efficiency. In addition, we conducted two tests, including leave-one-out tests and permutation tests, to check the robustness of estimated results, which also serve as an illustration of significance of the estimated results from an alternative empirical perspective. The results from these two tests are similar to each other, both indicating that the Zhoushan Archipelago New Area construction had a statistically significant positive impact on energy efficiency. Overall, our results suggest that marine economic development had a sizable improvement in energy efficiency. [ABSTRACT FROM AUTHOR]

Summary: With the continuous opening of China's electricity market, a large number of third‐party electricity retailers have poured into the electricity market. Electricity retailers are the bridge between the main player of the electricity market. In view of the large number and variety of electricity retailers in the current electricity market, this paper divides the electricity retailers that have been publicized in China into five categories. In view of the uncertainty of the credit evaluation standard of electricity retailers, this paper determines the cloud model scale of the risk level of the electricity retailers; selects three primary indicators, eight secondary indicators, and 20 tertiary indicators to construct the credit risk evaluation indicator system of the electricity retailer. This paper also builds a computing model combining intuitionistic fuzzy analytic hierarchy process (IFAHP) with cloud model; obtains the final evaluation score by combining the certainty of cloud model with intuitionistic fuzzy weight, the qualitative to quantitative change of the indicator is realized, and makes the fuzzy concept of credit rating of electricity retailers get a quantitative change. From the model results, it can be seen that the risk score of the electricity grid asset retailers is 14.8666, which is the lowest risk; the independent electricity retailers has a risk score of 26.9706, which is the highest risk. Compared with the traditional AHP‐cloud model, this method is not only more objective, but also can obtain more information such as the distribution of index values from entropy and hyper entropy. [ABSTRACT FROM AUTHOR]

The currently implemented indiscriminate subsidy policy in China is difficult to provide effective incentives for a firm's investment behavior because it does not take into account the differences in resource characteristics. Thus, this paper puts forward a type of differentiated subsidy that considers resource conditions, consisting of a basic guaranteed subsidy and a variable incentive subsidy. First, from the perspective of the economic efficiency of enterprises, the amount of basic subsidy required by enterprises is calculated by the discounted cash flow method. Then, from the government's perspective, a variable incentive subsidy amount is calculated by establishing an expectation benefit maximization function using principal-agent theory. The case application shows that due to the superior resources and development conditions of the Fuling block, it requires a significantly smaller subsidy amount than the Weiyuan block which verifies the need to consider regional differences in the design of shale gas development subsidies. [ABSTRACT FROM AUTHOR]

Clean energy is the core element of China's energy low-carbon transition strategy, and its development degree is closely link with science and technology innovation and higher education. Based on studying relevant research and analyzing data and information, we selected 11 primary indicators, such as investment in education, transformation of scientific research results, and clean energy development, and 30 secondary indicators, such as R&D investment intensity, number of patents granted for inventions, clean energy power generation, clean energy installed capacity, and clean energy consumption share, to construct an indicator evaluation system. Based on the actual data of three systems from periods 2010 to 2020, we try to use entropy weight method to calculate index weights, use coupled coordination model to calculate coupling coordination degree of three systems, and use gray correlation analysis method to in-depth analysis interaction relationships between three systems. Based on the research, we try to propose 3 countermeasures and recommendations. We hope that the research results of this paper will provide a new research method and ideas for related studies and make positive contributions to the high-quality development of China's economy and the realization of the energy transition strategy. [ABSTRACT FROM AUTHOR]

Summary: Lead‐based fast reactor is one of the most promising fourth‐generation nuclear energy systems. Fuel assembly design is a key technology for the research and development of lead‐based fast reactor. The current status of typical lead‐based reactors and fuel assembly design schemes in the world are reviewed in this paper, and also the key technical parameters and design features of fuel assembly are summarized, with the advantages and disadvantages discussed. A hexagonal fuel assembly that can achieve both "passive" and "active" axial positioning by the gravity of ballast unit and mechanical locking device proposed by the nuclear fuel assembly research group of China initiative Accelerator Driven System project at Institute of Modern Physics has been emphatically introduced. It is expected that this paper can provide certain supporting data and reference solutions for the further design and development of fuel assembly for lead‐based reactor. [ABSTRACT FROM AUTHOR]

Summary: Electric vehicle virtual energy storage technology can effectively improve the utilization of renewable energy. Aiming at the impact of the uncertainty of electric vehicle on the power grid, an optimized dispatching method of hybrid energy storage systems based on multiobjective optimization in the scenario of tracking plan output is proposed in this paper. The predicted value of the photovoltaic power obtained by the particle swarm optimization (PSO)‐back propagation (BP) neural network is used to formulate the planned output of photovoltaic power generation, and the principle component analysis algorithm is used to extract the main features affecting photovoltaic power generation to further improve the prediction accuracy of photovoltaic output power. From the perspective of the service life of electric vehicles, a two‐stage optimal control method of hybrid energy storage systems based on the complete ensemble empirical mode decomposition with adaptive noise (CEEMDAN) is used to achieve energy distributions between electric vehicles and supercapacitors. Fully consider the benefits of electric vehicle users and the capacity of tracking plans, a multiobjective optimization model of hybrid energy storage systems to track planned output is established, and the nondominated sorted genetic algorithm‐III is adopted to solve the model. The validity of the model is verified by a simulation test of actual operating data of a business park in China. The simulation results show that after the optimized control, the average absolute error of the deviation power reduces from 1.092 to 0.0528 MW, power fluctuating times of electric vehicles decreases from 151 to 80, and the daily income benefit increases from $404.468 to $483.116 in the cloudy day. The method proposed in this paper can effectively improve the controllability of renewable energy, and provide a theoretical basis for the application of electric vehicle virtual energy storage technology. [ABSTRACT FROM AUTHOR]

Summary: Distributed generation (DG) technologies are environmentally friendly and have low operating costs, and thus, distributed generators are widely used for the energy supplies of buildings. Solar energy used for on‐demand heating of buildings is also a mature technology that is environmentally friendly and inexpensive and has a short recycling life cycle. This paper proposes a high proportion of new energy access–combined cooling, heating, and power (HPNE‐CCHP) system composed of a distributed generator and solar energy heat pump system. To obtain the optimum capacity of the HPNE‐CCHP system, nondominated sorting genetic algorithm‐II (NSGA‐II) was used to optimize the system by considering the life cycle cost (LCC) and life cycle pollutant emissions (LCPE) as the objective functions. A mixed integer economic scheduling model (MIESM) was proposed to make the HPNE‐CCHP system operate more economically. Finally, an HPNE‐CCHP system was constructed for a building in Northern China. The simulation results show that an HPNE‐CCHP system with a moderate proportion of new energy is more economical and environmentally friendly than a traditional CCHP system. Building occupants, depending on their desired spending, can select the best capacity configuration on the Pareto frontier. Although pollutant emissions will be reduced as the proportion of new energy increases, this type of configuration is expensive. [ABSTRACT FROM AUTHOR]

Summary: A liquid‐fuel heat‐pipe reactor (LFHPR) is a novel fast heterogeneous reactor developed by Harbin Engineering University, China, on the basis of liquid‐fuel reactor designs and the heat‐pipe reactor concept. In the concept, the reactor abandons the graphite moderator and keeps neither fuel tubes arranged in the graphite nor fuel rings around the heat pipe. Instead, the reactor applies molten salt fuels, molten metallic eutectic fuels, or other fuels in liquid form. The heat generated in the reactor is removed by the heat pipes driven by liquid metals. With this change, an LFHPR is much more flexible in design and application and able to achieve several advanced features compared with conventional heat‐pipe reactors. In this paper, we describe the general reactor design of an LFHPR, discuss its potential advantages, and give a preliminary verification of the neutron physical feasibility for the reference case, which uses molten salt as the fuel, by using both Monte Carlo and deterministic methods. Results show that the LFHPR yields a hard neutron spectrum that brings a very good neutron economy and is a promising application for breeding. From our approach, we conclude that the proposed LFHPR has a very high power density and high negative temperature feedback coefficient. [ABSTRACT FROM AUTHOR]

Summary: As the installed capacity of wind power continues to increase, the problem of curtailed wind power is becoming serious in China, especially in the northern region during the winter heating season. To solve the problem of wind‐heat conflict during the heating period in the Three North area, an electric boiler with thermal storage (EBTS) is installed at the end of the grid where wind power is difficult to accommodate and using curtailed wind power to supply heat promotes local accommodation. In this paper, a multi‐objective optimization model of wind power accommodation based on the wind power–EBTS system for heating is established. The goals of maximizing wind power accommodation, minimizing the number of times EBTS must be adjusted, and minimizing operating costs are presented, and a bi‐level optimization scheme is designed. An improved multi‐objective particle swarm optimization algorithm is used to solve these functions, and an optimal compromise solution from the generated Pareto solution set is filtered using the fuzzy membership method. Based on actual data from a demonstration project in China's Jilin Province, the simulation results verify that this method can effectively reduce operating costs and improve wind power accommodation. [ABSTRACT FROM AUTHOR]

Summary: For the first time, this paper investigates the relationship between crowdfunding and renewable energy generation for a panel of 32 countries from 2013 to 2018. Applying the instrumental variable generalised method of moment, this study indicated that crowdfunding has a significant positive effect on renewable energy generation. Notably, 1% increase in crowdfunding raises renewable energy generation by 0.35%. Specifically, we also found that crowdfunding spurs the generation of solar energy (0.45%), wind energy (0.37%), and other renewable energy (0.30%) while having a neutral effect on hydroelectricity generation. The findings from the causality analysis showed that there is bi‐directional causality between crowdfunding and renewable energy generation. Country‐specific analysis indicated that China has the highest effect of crowdfunding on renewable energy generation, while the United Arab Emirates has the lowest effect. These findings suggest that policymakers need to advance crowdfunding development by promoting favourable regulations, social capital (trust), and internet infrastructure investment. Policies that advance renewable energy generation, such as subsidies, feed‐in‐tariffs, and technology procurement, are also recommended. Highlights: Examines the effect of crowdfunding on renewable energy generation.Use a panel of 32 countries from 2013 to 2018.Crowdfunding drives renewable energy generation.There exists bi‐directional causality between crowdfunding and renewable energy generation.China has the highest effect of crowdfunding on renewable energy generation. NOVELTY STATEMENT: This study has, for the first time, measured the contributions of crowdfunding to renewable energy generation. The study has also demonstrated that there exists bi‐directional causality between crowdfunding and renewable energy generation. Finally, this study has shown that China has the highest effect of crowdfunding on renewable energy generation. [ABSTRACT FROM AUTHOR]

Summary: Energy internet (EI) is a complex coupled multienergy system; it is essential to investigate its multienergy dispatching optimization issues. To this end, this paper first proposes a novel conception of smart dispatching for EI with a complex cyber‐physical‐social system (CPSS) network from the perspective of parallel dispatch, called parallel dispatching robot (PDR), and investigates the implementations of PDR based on smart artificial society (SAS) modeling. First, we introduce EI and describe the dispatching issues of EI. Second, we discuss several important concepts supporting the parallel dispatch conception of EI, including knowledge automation (KA), CPSS, and parallel machine learning (PML). On the basis of these, we elaborate the concept of parallel dispatch. Moreover, we construct a large closed‐loop feedback control framework of parallel dispatch for EI integrating a CPSS network based on KA and PML. Third, we establish an experimental platform for PDR research based on the proposed parallel dispatch framework. Fourth, we develop the PML‐based SAS models of a single PDR in centralized dispatching modes and group PDRs in decentralized dispatching modes to achieve crowd wisdom emergence and performance improvement in current cyber‐physical system frameworks of EI. Moreover, we design an external global closed loop for PDR to evaluate its operation stability. Lastly, we conduct a detailed discussion on PDR and offer some prospects for its engineering implementations. The biggest innovation of this paper lies in systematically proposing the smart dispatching concept and framework for complex CPSS‐based EI from the perspective of parallel dispatch and thoroughly investigating how to use SAS modeling to implement parallel dispatching and control for EI considering human and social factors, which is a major extension and theoretical improvement to existing single smart wide area robot concept and a preliminary attempt in investigating a shift from Energy 4.0 to Energy 5.0 in China. [ABSTRACT FROM AUTHOR]

Summary: Access to energy has increasingly been provided by the Chinese Government via new alternative energy sources known as renewables in recent years. Meanwhile, the development and use of environmentally friendly renewables gradually become the basic requirements for the sustainable development in the future society. The integration of blockchain technology with distributed photovoltaic (PV) energy may break the existing pattern where the production, transportation, distribution, and sales of energy are centralized. This paper first reviews the current overall situation of China's distributed PV and further analyzes the policy environment with respect to the development of distributed PV. On the basis of the analysis of the status quo, the paper then discusses the internalities (strengths and weaknesses) and the externalities (opportunities and threats) that have driven the development of China's distributed PV by illustrating the SWOT analysis. The data structure and characteristics of blockchain are analyzed to identify the application mode of blockchain technology in the distributed PV industry for the first time. Through our research, some conclusions and policy proposals are finally put forward to provide support to the formulation of related policy in the Chinese Government and industry association. [ABSTRACT FROM AUTHOR]

Summary: The consumption of fossil fuel has resulted in global warming, environmental pollution, and many other crucial problems. Replacing fossil fuel with renewable energy has become an important issue over the recent decades. As a renewable clean energy, wind power is a relatively well‐developed and promising energy method for current technology development in China. Under the background of growing demand for electricity and enhancing awareness for environmental, the “Internet+ wind power” concept has emerged based on both the wind power's characteristics that renewable and non‐polluting, and the rapid development of the Internet in China. Through querying an amount of literature and information, this paper reveals the resource endowment and policy environment about wind power and energy Internet at first. Then, the PEST‐SWOT strategy analysis model is used to analyze the internalities (strengths and weaknesses) and the externalities (opportunities and threats) of “Internet+ wind power”. According to these results, the paper puts forward some measures (development and utilization, business mode) for wind power accommodation. Then some policy recommendations have been proposed. The government should provide favorable conditions for wind power grid with the “Internet+” technology innovation. [ABSTRACT FROM AUTHOR]

Summary: Since the economy of the energy storage system (ESS) participating in power grid ancillary services is greatly affected by electricity price factors, a flexible control method of the ESS participating in grid ancillary services based on electricity price forecasting is proposed in this paper, and the economic evaluation of the ESS participating in ancillary services is realized by the net present value (NPV) method. To improve the accuracy, the Markov chain is adopted to correct the predicted electricity price value obtained by the combination of the particle swarm optimization (PSO) and back propagation (BP) neural network according to the systematic errors in the modelling process. Based on the compatibility of each ancillary service, taking the maximum revenue of the system as the objective function, a flexible control model of the ESS participating in ancillary services based on electricity price forecasting is established, and the YALIMP+CPLEX software toolbox in MATLAB is adopted to solve the problem of electricity price forecasting, and the capacity division of the ESS under the ancillary service application scenarios is realized. The NPV method is used to evaluate the economics of the ESS participating in ancillary services under this strategy. The simulation analysis of the actual operation data from a power grid in China validates the effectiveness of the proposed method. The simulation results show the proposed method can provide theoretical support for the ESS participating in power grid ancillary service markets. [ABSTRACT FROM AUTHOR]

Summary: Extraction residue (ER) is, in this study, considered as an insoluble portion derived from a novel extraction process with direct coal liquefaction residue, which is the byproduct from 1000 kton/y direct coal liquefaction and oil production process in Ordos, China. ER mostly consists of unreacted coal and minerals, spent catalyst, and solvent. It is considered as a hazardous waste in China. Gasification is a promising way to employ ER, as the carbon resource contained in it could be adequately utilized, so strongly reducing the environmental impact of this material. In this paper, a kinetic study is carried out concerning CO2 gasification (in thermobalance) of ER char, coal char, and their blends. The results show that, at temperatures ranging from 1123 to 1323 K, the reactivity of ER char is much larger than that of coal char, and the reactivity of ER/coal char blends increases when the ER fraction increases, consistently resulting in between the reactivities shown by ER char and coal char alone. The partial pressure of CO2 promotes the reactivity of all samples. BET surface area resulted three times larger for ER char vs coal char, while pore surface area and pore volume were four times larger. Moreover, the relevant parameters of the random pore model for CO2 gasification of ER char, coal char, and their blend #2 (with 20% ER) were obtained; the activation energy resulted 210.6, 240.5, and 232.8 kJ/mol, and the reaction order 0.30, 0.45, and 0.40, respectively. [ABSTRACT FROM AUTHOR]

Summary: Currently, both the heated building area and total pipe length have been increased significantly. Despite the rapid development of China's heating industry, the overall efficiency of district heating systems is relatively low. In this paper, an innovative smart and transparent heating mode is proposed to solve the problems of the current heating mode. The proposed method integrates two core technologies: the 3D‐GIS digital twin model and the NB‐IoT wireless communication system. The concept, main characteristic of the proposed heating mode is discussed. A concrete technical scheme of the heating mode integrating the static and dynamic data of DHN is presented. To test the feasibility and effectiveness of the proposed heating mode, two cases with a concrete implementation scheme are presented. The energy reduction rate, pump efficiency, and hydraulic imbalance level of proposed heating mode is compared with the traditional heating mode. Results show that the energy consumption of DHN under traditional set secondary‐side supply target temperature control mode can be reduced by 26.11% compared with smart and transparent heating mode during the heating period. [ABSTRACT FROM AUTHOR]

Summary: As the uncertainty of renewable energy output brings more and more risks to the day‐ahead dispatch of the power grid, an optimization scheduling strategy of a smart energy system based on improved master‐slave game model is proposed. Risk factors related to the uncertainties of renewable energy are introduced into the master‐slave game model. Taking the smart energy system as the leader and the end users as the follower, an optimized operation model of the smart energy system based on the improved master‐slave game model is established, which is transformed into a single‐layer linear programming model according to the Karush‐Kuhn‐Tucher conditions and the duality theorem. The benefits of the system and electric vehicle users in four application scenarios are obtained by the YALMIP algorithm and the sensitivity affecting the economics of the smart energy system is analyzed. The validity of the model is verified by a simulation analysis of actual operation data from the smart energy system in China. The simulation results show that the method proposed in this paper can increase the revenue of the smart energy system by 7%, reduce the risk cost and charging cost of electric vehicle users by 63.92% and 48.34%. [ABSTRACT FROM AUTHOR]

Summary: This paper considers the co‐optimization operation problem of the multiple micro energy grids (MEGs), and proposes a novel concept of the flexible boundary. Then, a three‐level co‐optimization model of reconfiguration, dispatching, and reserve is designed considering different time scales. Furthermore, an improved ant colony algorithm based on the information entropy and the chaotic search is proposed. The Shenzhen international low‐carbon park in China is selected as an example. The results show that: (a) The capacity configuration scheme considering the flexible boundary conditions could decrease the reserve capacity of power, heating, and cooling from the upper energy grid, namely, 75%, 50%, and 75%, and delay 537 × 104¥ the investment cost of the new capacity by utilizing the complementary characteristics between different MEGs. (b) The proposed three‐level co‐optimization model could establish the multi‐level optimal cooperative operation schemes of multi‐MEGs and decrease the reserve power from the upper energy grid and incentive‐based demand response. Among them, UPG provides MEG 1, MEG 2, and MEG 3 with cooling load reserve capacity reduction of 53.95, 85.44, and 38.3 kw h. The positive reserve provided by IBDR for MEG 1, MEG 2, and MEG 3 decreased by 30.53, 20.21, and 52 kW h. (c) The proposed improved ant colony algorithm can consider the operational characteristics of each energy entity in different stages of multi‐MEGs and obtain the global optimal operation scheme. Compared the traditional ant colony algorithm, the average convergence times decrease by 18% and the optimization degree of the objective value increase by 12.38%. (d) The sensitivity analysis shows the conditional value at risk method can formulate the optimal dispatching schemes of multi‐MEGs according to the risk attitudes of decision makers. When confidence degree is between 0.3 and 0.8, the decision‐makers have a high‐risk sensitivity and are more willing to avoid uncertain risks of wind power plant and photovoltaic power. Overall, the proposed model and solution algorithm could achieve the optimal operation strategy of the micro energy grids. [ABSTRACT FROM AUTHOR]

Summary: China's high‐speed economic growth and ambitious urbanization depend heavily on the massive consumption of fossil fuel. However, the over‐dependence on the depleting fossil fuels causes severe environmental problems, making China the largest energy consumer and the biggest CO2 emitter in the world. Faced with significant challenges in terms of managing its environment and moving forward with the concept of sustainable economic development, the Chinese government plans to move away from fossil fuels and rely on renewables such as hydropower, wind power, solar power, biomass power and nuclear power. In this paper, the current status of China's renewable energy deployment and the ongoing development projects are summarized and discussed. Most recent developments of major renewable energy sources are clearly reviewed. Additionally, the renewable energy development policies including laws and regulations, economic encouragement, technical research and development are also summarized. This study showcases China's achievements in exploiting its abundant domestic renewable energy sources to meet the future energy demand and reducing carbon emissions. To move toward a low carbon society, technological progress and policy improvements are needed for improving grid access (wind), securing nuclear fuel supplies and managing safety protocols (nuclear), integrating supply chains to achieve indigenous manufacture of technologies across supply chains (solar). Beyond that, a preliminary prediction of the development of China's future renewable energy developments, and proposes targeted countermeasures and suggestions are proposed. The proposal involves developing smart‐grid system, investing on renewable energy research, improving the feed‐in tariff system and clarifying the subsidy system. [ABSTRACT FROM AUTHOR]

Currently, hybrid renewable energy systems with thermal energy storage have various advantages and are widely used. This paper investigated the performance of a solar‐assisted air source heat pump system with energy storage (SASHPS‐ES) in Beijing, China, and proposed an optimal operation mode based on economic evaluation. The results indicate that with the optimal heat storage ratio of 50%, the rated capacity of the air source heat pump (ASHP) of the SASHPS‐ES system can be reduced by 16.7%, decreasing its annual total cost by 26.5% under a peak‐valley electricity price policy. The price of 620¥/m2 is critical for the solar collectors. The economics of SASHPS‐ES is better than that of an air source heat pump system with energy storage (ASHPS‐ES) when the price of the selected solar collector units is less than this critical price (without subsidies from the government). In the current local market, the promotion of SASHPS‐ES systems and other solar energy applications requires government subsidies for a period of time. The results can guide the utilization and popularity of SASHPS‐ES in China. [ABSTRACT FROM AUTHOR]

Summary Electric heating is perceived as an effective way to tackle heavy wind curtailment and severe smog in northern China, wherein distributed electric heating (DEH) accounts for a significant proportion. However, more research is required with regard to its thermal characteristic. This paper presents the multiperiod heating storage control for a DEH load to reduce wind curtailment. To cope with intermittent wind power, a novel multi‐objective and layered optimization method is proposed by decomposing the integrated electricity and heating optimization problem into the electricity optimization subproblem and the heating optimization subproblem. Additionally, the influence of solar radiation on the thermal characteristic of the DEH load is considered in the building thermal process model when creating the day‐ahead schedule of the DEH load control, and this is also regarded as the basis for grouping DEH users. Last, the simulation and economic feasibility analysis based on the data measured by the DEH system of Jilin Province, China, are carried out. The results show that this proposal can reduce the electricity cost for DEH users by 25%, and the critical feasible price for curtailed wind power is varying between 86.1 and 115.3 yuan/MWh according to different subsidy methods. [ABSTRACT FROM AUTHOR]

Summary: Power‐to‐gas storage (P2GS) provides a new approach for clean energy accommodation, which could be used to support the development of the microenergy grid (MEG). This paper designs a novel structure of MEG including power sources, heating sources, and P2GS. The risk condition values (CVaR) is applied to analyze the uncertainties from wind power plant, photovoltaic power generation, and solar collectors, and a multiobjective optimal model is proposed for balancing the operation economic benefit and the risk level. Then different membership functions are selected for converting the multiobjective model into a mixed integer programming model. Finally, an industrial park in northern China was selected to verify the proposed model. The results show that (a) complementary effect exists in different clean energy sources and P2GS can convert excess energy into CH4 for power generation, which are better for achieving the power‐to‐gas‐to‐power cycle optimization effect. (b) The proposed optimal model could balance revenue and risk, rationally control its operation risk while pursuing the maximum operation benefits, which is better to achieve MEG's optimal equilibrium operation. (c) Maximum emission trade allowance could enhance MEG's enthusiasm for clean energy accommodation, and P2GS could be a feasible way for near‐zero carbon emissions. Therefore, the proposed risk aversion optimal model could increase the economic benefits and control the risks and provide decision support for decision makers. [ABSTRACT FROM AUTHOR]

Summary: In recent years, with the rapid growth of photovoltaic (PV) power development and utilization, part of the PV power could not be transmitted to the power grid owing to the impact of PV power fluctuation on power quality, leading to a serious PV power rejection in some areas in China. A high‐order model of a hydro‐PV power plant is developed in this paper not only to predict hydropower compensation for PV power fluctuation but also to consider the impact of complementary regulation on power quality. Compared with the existing complementary models, the presented model accurately reveals the effect of water hammer on power quality, low‐frequency power oscillation, and power antiregulation phenomenon during the complementary regulation. Although the complementary control of the hydro‐PV power plant helps to suppress power fluctuation, when the PV power and objective power are negative covariation, the hydropower needs more regulation, which will cause an increase in frequency fluctuation. Moreover, with the increase of the ratio of hydro‐PV power in the power grid, the frequency fluctuation amplitude increases accordingly. Especially, when PV power exceeds the regulation ability of the hydropower, the system frequency deviation will increase rapidly. These problems are worth the attention to the future development of PV power. [ABSTRACT FROM AUTHOR]

Summary: The negative environmental impacts of burning fossil fuels have forced the energy research community seriously to consider renewable sources, such as naturally available solar energy. This paper provides an overview of solar thermoelectric (TE) cooling systems. Thus, this review presents the details referring to TE cooling parameters and formulations of the performance indicators and focuses on the development of TE cooling systems in recent decade with particular attention on advances in materials and modeling and design approaches. Additionally, the TE cooling applications have been also reviewed in aspects of electronic cooling, domestic refrigeration, air conditioning, and power generation. Finally, the possibility of solar TE cooling technologies application in “nearly zero” energy buildings is briefly discussed, and some future research directions are included. This research shows that TE cooling systems have advantages over conventional cooling devices, including compact in size, light in weight, high reliability, no mechanical moving parts, no working fluid, being powered by direct current, and easily switching between cooling and heating modes. [ABSTRACT FROM AUTHOR]

Summary: Sustainable energy production has been one of the contemporary concerns of society. In order to mitigate carbon dioxide emissions while generating the required demand for energy, various energy technologies, and production systems must be considered. In the consideration of different energy technologies, optimization is one of the important tools to optimally design energy systems. This study aims to analyze the progress of current research related to energy and sustainability that utilizes fuzzy optimization approach. Bibliometric methods based on the database of Web of Science core collection are used for the analysis. Of the 96 retrieved publications, 87% were journal articles. Analysis on the patterns for these articles were conducted such as highly cited articles, journals, subject categories, institutions, countries, and impact factor. The articles are evaluated into three categories such as technological, environmental, and economy and are comprehensively reviewed. The results showed a significant increase in publication related to fuzzy optimization in sustainability and energy technologies. The analysis showed China with 26 publications, which has the largest contribution in terms of the number of articles published. North China Electric Power University ranked as the number 1 institution with 10 publications. Based on the comprehensive analysis, fuzzy optimization showed significant results on technological, environmental, and economical factors. These findings help to identify hotspots in energy technology optimization for sustainability research. Similarly, the study gives useful inputs for selecting subtopics and strategy on publication related to fuzzy optimization on energy technologies. [ABSTRACT FROM AUTHOR]

The pore-fracture structure of deep coal reservoirs is highly important for evaluating, exploring, and developing coalbed methane (CBM) resources. This study considers three coal samples from the DJ57 well in the Benxi Formation in the Daning–Jixian block on the eastern margin of the Ordos Basin as the research object. Based on the coal quality parameters of the coal samples, field emission scanning electron microscopy (FE-SEM), gas adsorption experiments, high-pressure mercury intrusion porosimetry (MIP), and microcomputed tomography (micro-CT) scanning were used to quantitatively characterize the nanoscale pores and microscale fractures in deep coal reservoirs and to evaluate the pore-fracture structure at different scales. The results reveal that the pore types in the Benxi Formation coal samples are diverse and include mainly organic matter (OM) pores, inorganic pores (intraparticle and interparticle pores), and microfractures. The organic pores are diverse in shape and mainly exhibit round, oval, and wedge shapes, while the microfractures exhibit slender stripes or serrated curves. The multiscale quantitative characterization of deep coal reservoir pores and fractures is based on a variety of pore characterization methods, and the pore and fracture volume distributions are mainly U-shaped, revealing the coexistence of micropores and microfractures. The volumes of micropores (0.3–2 nm), mesopores (2–50 nm), macropores (50 nm to 10 μm), and microfractures (>10 μm) account for 78.00%, 6.78%, 2.08%, and 13.14%, respectively, of the total pore volume (PV). Based on a full-scale pore-fracture splicing calculation, the total permeability of the Benxi Formation coal samples ranges from 5.77 to 28.22 mD. The observation results indicate that the microfractures are connected to each other, forming a network structure with strong connectivity. The microfractures are mainly associated with pore diameters > 100 μm, accounting for approximately 95% of the total permeability. Moreover, micropores in deep coal reservoirs provide a large space for CBM adsorption, and microfractures enhance the seepage capacity of CBM. [ABSTRACT FROM AUTHOR]

A project to develop the Accelerator Driven System (ADS) for nuclear waste transmutation has been launched by Chinese Academy of Sciences (CAS) since 2011 through three stages. China LEAd-based Reactor (CLEAR) was selected as the reference reactor for CASADS project, which means lead or lead-bismuth will be used as the primary coolant for reactor. Institute of Nuclear Energy Safety Technology (INEST), CAS, is one of the leading teams being involved in ADS project, and taking charge of the design and R&D activities of CLEAR series reactors. According to the research and development roadmap of CLEAR, a 10MWth lead-bismuth cooled pool-type research reactor named CLEAR-I coupled with a proton accelerator will be constructed at the first stage. In the second stage, China LEAd-based Engineering Demonstration Reactor (CLEAR-II) with 100MWth will be constructed. In the third stage, China LEAd-based Commercial Prototype Reactor (CLEAR-III) with 1000MWth will be constructed. In order to verify the key components and investigate the thermal-hydraulics phenomena for CLEAR-I and even for pool type lead-based reactor, an integrated multifunctional non-nuclear test facility named CLEAR-S will be built and commissioning before the end of 2016. Note that CLEAR-S will be used to test the 1:1 prototype components for CLEAR-I, such as primary pump, heat exchanger, control rod driven system and in-vessel refueling system, and to verify the design and safety analysis codes. In this paper, the design description and latest progress have been presented for CLEAR-S. © 2016 The Authors. International Journal of Energy Research Published by John Wiley & Sons Ltd. [ABSTRACT FROM AUTHOR]

SUMMARY In order to solve the contradictions that the static input-output table cannot be used for dynamic analysis, this paper unified the 2002, 2005, and 2007 input-output tables into 25 industries. Full energy intensity and embodied energy of China's export trade can be calculated quantitatively based on input-output analysis approach. We can get the time series data of 2001-2009 through the corrections of energy consumption per unit of gross domestic product, consumer price index, and exchange rate, and then analyze the trends of energy consumption of key industries. The results show that full energy intensity of China's 25 industries takes on downward trend generally, and the embodied energy of China's export trade is increased firstly and then has a downward trend. Processing trade had great impact on full energy intensity and embodied energy after deducting the processing trade; full energy intensity and embodied energy had decreased greatly. Smelting and pressing of metals, manufacture of chemicals, manufacture of communication equipment, computers, and other electronic equipment, and manufacture of textile are the largest energy-consuming industries of export trade in China. The trends of energy consumption in these four industries are similar to the total energy consumption; changes in export trade is the main reason for this result. Full energy intensity has a certain influence on the trend of energy consumption, but the effect is limited. Copyright © 2013 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

This paper presents a case study of the prediction, potential and control of plume in wet cooling towers from a huge commercial building in Hong Kong based on the weather data available for a particular year. The power input is found to be lower and the coefficient of performance (COP) moderate when all the 10 towers with low speed are in use, while it is found to be reverse when there are five towers, especially, three low and two high-speed towers are used. It is also found that the combined heating and cooling option can be a better approach than that of the heating option alone from the point of view of thermodynamics as well as from the point of view of economics. The COP of the chillers increases from 6.01 to 7.09 when the number of cooling towers increases from five to ten. On the other hand, the power consumption first decreases and then increases which is mainly due to the increment in the consumption of fan power from 270 to 900 kW for both options. The overall power consumption decreases slightly for the combined heating and cooling option, while in the heating option, the overall power consumption increases slightly. However, it is observed that a proper operation of cooling towers is an effective means to control and/or at least reduce the potential of visible plume generated by wet cooling towers at the existing chilling plant design for this particular building. Copyright © 2006 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

Based on the project of National Highway No. 310 located in Sanmenxia City, China, field tests on the thermal responses of the 2 × 2 pile groups under embankment load in winter condition are carried out. The temperatures and stresses of piles along pile depth under the combined action of embankment load and temperature are measured. The thermal characteristics of the pile body, such as thermal-induced stress, cumulative deformation of the pile top, and heat exchange efficiency per unit area, are analyzed. The feasibility of a new piping method compatible with the segmented reinforcement cage is discussed. A calculation method for heat exchange in a large-diameter energy pile is proposed. The layout of the heat exchange pipe used in this study is feasible, and there is no large stress mutation in the dense and nondense areas. The maximum tensile stress in the middle of the pile body is about 0.4 MPa, which is nearly 22% of the concrete tensile strength value. The settlement of the pile top is about 0.33 mm after seven days of cooling condition, which is about 0.27‰ of the pile diameter. [ABSTRACT FROM AUTHOR]

Summary: A building‐integrated photovoltaic energy system (BIPVS) with demand response (DR) is gaining increasing interest in improving building energy consumption to address the imbalance between energy supply and demand. The application of DR in the BIPVS literature lacks consideration of the spatial variability of solar resource distribution. The impact of DR scheduling on the optimum sizing and operation of a BIPVS requires an understanding of how DR can adapt to the uncertain energy generation patterns caused by diverse solar intensity curves. To fill this research gap, an integrated photovoltaic electricity and heating energy system are considered to meet electricity and domestic hot water demands in residential buildings. A DR strategy based on load rescheduling has been illustrated and modeled. To solve the proposed issue of optimum sizing and operation, a two‐stage optimization method has been developed to minimize the cost of energy (COE). Furthermore, after the selection of four typical cities in China as potential locations for system deployment, eight scenarios based on four different solar intensity curves without and with DR are investigated and compared. The results show that the DR scheduling has been shifted towards the availability of irradiance to form a load peak at the same time as the peak solar radiation, which increases the direct consumption of photovoltaic generation and inhibits the battery dispatch. In comparison with each scenario, DR has great potential in economic performance and leads to a slight reduction in photovoltaic penetration rate. It has been observed that DR can decrease the COE with an average saving of $0.0052/kWh and a maximum reduction rate of 11.1%, while significantly reducing the battery size by 92.9% on average. [ABSTRACT FROM AUTHOR]

Summary: The development of carbon emission reduction technologies and clean energy utilisation are two critical drivers for reducing and controlling greenhouse gas (GHG) emission from human activities. Carbon capture, utilisation, and storage (CCUS) is an established and crucial emission reduction technology capable of achieving near‐zero‐emission from fossil fuels. Hydrogen, a zero‐carbon fuel, provides energy security while improving air quality. However, hydrogen is commonly derived from fossil fuels with significant associated CO2 emission. Hence, this study investigates the feasibility of integrating CCUS in the hydrogen industry, particularly from technical, sustainability, and policy perspectives. This study also critically reviews existing CCUS and hydrogen production technologies and discusses the prospects and challenges of each. Studies show that CO2 enhanced oil recovery (CO2‐EOR) and CO2 enhanced coal‐bed methane recovery (CO2‐ECBM) are promising CCUS technologies in China, while producing clean hydrogen from fossil fuels with CCUS and water electrolysis are ideal development route. Specifically, this study proposes the coupling technical route of CCUS + SMR (steam methane reforming) and CCUS + CTH (coal‐to‐hydrogen) to accelerate carbon emission reduction by 2050 considering their promising carbon reduction potential and the ratio of hydrogen with CCUS. Besides, CO2 hydrogenation integrated chemical production is becoming increasingly popular to achieve carbon emission reduction and low‐carbon economy. However, the relatively high costs and lack of hydrogen transportation infrastructure is currently the major bottleneck restricting the development of CCUS and hydrogen industry. Therefore, government subsidies, standardised operation of the carbon market, and technological innovation are useful strategies to address this issue. [ABSTRACT FROM AUTHOR]

Summary: Platinum catalysts for use in fuel cells have gained much attention because of their unique properties such as high catalytic activity and durability. They have enabled a number of different electro‐catalysts for diverse applications. Nanomaterials based platinum (Pt) electro‐catalysts for fuel cell applications have been largely explored and actively utilised to meet those alternate energy needs. This bibliometric analysis examines developments from 1990 to 2019 in the area of Pt electro‐catalysts for fuel cells. A total of 4674 documents were retrieved from two databases (Web of Science and Scopus) after eliminating duplicates with an author per article and article per author ratios of 1.79 and 0.559, respectively, while the collaborative index stood at 1.81. Rstudio software was used to process the retrieved data for bibliometric analysis. The information analysed using this software was annual research output, research by journal, research by countries, research directions, research collaboration index, and frequently used keywords. The analysis showed that studies on Pt based electro‐catalysts for fuel cell have continuously grown over the years with a positive correlation of (y = 0.669x2‐3.7983x + 2.9365; R2 = 0.9738) and leading electrochemical journals accounted for most publications on this subject. The study revealed that China and the USA with a contribution of 1339 articles (28.70%) and 593 articles (12.71%), respectively, dominated research in this field. This study clearly demonstrates the growing research in fuel cell and their use as alternate energy source, which will promote community and industry engagements as well as increase awareness of fuel cell technology. [ABSTRACT FROM AUTHOR]

Summary: Improving energy utilization efficiency and exploiting renewable energy source have become more crucial with the growing concern on energy crisis and environmental problem. Organic Rankine cycle, a clean, low‐cost, and efficient energy utilization technology, is eliciting increasing attention. In this study, the recent research studies on organic Rankine cycle configuration modifications integrated with pure organic fluid are summarized from the perspectives of nomenclature, configuration modifications, theoretical and numerical methods, and experimental development. Results reveal that the nomenclature on the common organic Rankine cycle configurations is confusing; the research studies on organic Rankine cycle configurations are mainly focused on numerical research studies, and theoretical and experimental research studies are relatively limited. The experimental and numerical studies are mostly related to organic Rankine cycle with a recuperator due to its higher thermal and exergy efficiencies. Most experimental research studies are contributed by Chinese scholars, which indicate that China has paid much attention to improving the global environment. More theoretical and experimental research studies on other organic Rankine cycle configurations are urgently needed. [ABSTRACT FROM AUTHOR]

Summary: Closed type assembly leads to complicated core thermohydraulics which are significant for design and safety analysis in sodium‐cooled fast reactor (SFR). Most of the major phenomena can be dealt with by general parallel channel network and two‐dimensional model for inter‐wrapper flow (IWF) in system code transient thermal‐hydraulic code for analysis of SFR (THACS). A main deficiency left is the overestimation of inter‐assembly heat transfer effect due to lump temperature message that one‐dimensional assembly model can only provide. A methodology was thus developed to compute wall‐subchannel temperature for simulating energy transportation through duct wall. Intra‐assembly thermohydraulics were classified as two mechanisms and non‐dimensional parameter was introduced for characterizing each of them. Ratio between linear heat flux density through hexagonal wrapper surface and pin surface qw/p was employed to account for radial heat transfer. Flow redistribution effect arouse in mixed and natural convection was concretized by a importance symbol of buoyancy force, Richardson number Ri. Two criteria were also proposed for dividing flow state into three parts and specific model for each section was defined. Two validation cases against 3‐D computational fluid dynamics (CFD) simulation of China experimental fast reactor whole core and test data from plant dynamics test loop with direct heat exchanger experiment were performed with THACS. Noticeable improvement after incorporation of this model demonstrated its value in system analysis. Although the procedure for parameter computations is geometry related, this method can be reproduced to any type of assembly directly. [ABSTRACT FROM AUTHOR]

Summary: The liquid lithium lead (LiPb) blanket concept has become a promising design for fusion reactor, for example, international thermonuclear experimental reactor (ITER) and the demonstration (DEMO) reactor. To promote the successful application of fusion energy, detailed studies on key issues of the LiPb blanket were performed, such as corrosion behavior, thermal hydraulics and coolant safety etc. Some experimental facilities needed for the key issue studies were designed and developed under the research program. The series LiPb experimental loops, named DRAGON, were developed in China, including the thermal convection loops DRAGON‐I/II/III and the multi‐functional experimental loop DRAGON‐IV. To perform the integrated experiments under the multi‐physical field conditions for DEMO blanket, a dual‐coolant thermal integrated experimental loop DRAGON‐V was built in 2017. It is a multi‐functional test platform for the research and development (R&D) of key issues of liquid LiPb blanket to provide the necessary database for ITER and DEMO. Up to now, a lot of experiments have been performed to investigate the LiPb technologies, such as corrosion behaviors of structural materials both with and without magnetic field, corrosion resistance technology, magneto‐hydrodynamics effect, and interaction between typical coolants during in‐box loss of coolant accident etc. The results will support the R&D of the key techniques and the engineering design for ITER test blanket module and further DEMO. [ABSTRACT FROM AUTHOR]

Summary: Thermochemical energy storage, a promising candidate for seasonal solar thermal energy storage, offers an economic solution to mitigate the use of fossil fuels and CO2 emissions due to its large storage density and almost zero‐loss long‐term storage. The present article explored the potential of the thermochemical seasonal energy storage system using MgO/Mg(OH)2 system for solar district heating applications in China. The solar district heating model with thermochemical seasonal energy storage system, including the parabolic trough solar collector and a chemical reactor, has been built. The dynamic charging/discharging performance of the seasonal solar thermal energy storage system has been simulated and analyzed by using the real weather data and the practical domestic heating demand. The optimal parameters of the equipment have been identified. And the comparison of the performances between thermochemical seasonal energy storage system and the conventionally used water storage tank system has been carried out for various areas of China. The results indicate that the stored thermochemical energy is able to contribute 94.6% of heating demand in the discharging stage, demonstrating the application potential of MgO/Mg(OH)2 thermochemical energy storage system in China. The needed solar collector areas of the seasonal thermochemical energy storage system decrease by up to 2/3 compared with those of a water storage tank system in the condition of the similar storage system volume. The advantage of seasonal thermochemical energy storage is more obvious for the case of region with abundant solar energy supply. [ABSTRACT FROM AUTHOR]

Summary: Owing to the low coal permeability coefficients and poor gas extraction efficiencies associated with the extraction of coal in the Huainan coal mining area, the aim of this study was to design, for the first time, a high‐pressure low‐temperature liquid CO2 (LCO2) pump for engineering tests with respect to the fracturing of coal seams and the improvement of CH4 recovery in China. To reasonably calculate the initiation pressure for the coal seam fracturing as well as the gas flow parameters, theoretical analysis with field testing were integrated in the design. In addition, considering the interim gas extraction standard, the gas extraction equivalent radius based on this standard was calculated. The test results revealed a maximum LCO2 pressure of 20.6 MPa, which surpasses the theoretical maximum pressure (19.5 MPa) required for the fracturing of coal seams. During the entire gas extraction process, the CO2 concentrations in boreholes K1 and K3 decrease exponentially with time, showing attenuation coefficients of 0.0205 and 0.0231, respectively. The attenuation coefficients of the three attenuation stages of the original coal seam gas flow rate were 0.0314, 0.2142, and 0.1198, which were higher than those corresponding to the test area. The CH4 concentration in boreholes K1 and K3 in the test area were both higher than that in the original coal seam, and the maximum CH4 flow rates in these boreholes were 1.31‐ and 1.72‐fold higher than that in the original coal seam, respectively. The comparative analysis of CH4 concentrations and flow rates indirectly showed an improvement in the permeability of the coal seam. Further, a quantitative equivalent gas extraction evaluation method based on LCO2 fracturing of coal seam and gas displacement was proposed. Furthermore, based on a comprehensive evaluation, the effective displacement radius caused by the LCO2 fracturing test was 9 m, with a displacement efficiency of 23.95%, and a displacement volume ratio of 0.21. This method offered the possibility of realizing the quantitative evaluation of the LCO2 injection amount and the gas extraction effect, and provides a basis for optimizing the LCO2 fracturing of coal seams as well as the gas extraction process. [ABSTRACT FROM AUTHOR]

Summary: Tremendous amounts of organic residue from manufacturing herbal medicines and inorganic red mud waste from mining bauxite ores are landfilled each year in China. To study the potential for their beneficial co‐use, chemical looping gasification (CLG) was tested in which the organic residue was used as the fuel and the red mud was the oxygen carrier that is needed for CLG. Parametric testing was performed using a thermo‐gravimetric analyzer and a bench‐scale fluidized bed reactor to optimize CLG operations that could maximum syngas production, enrich H2 concentrations and obtain effective conversion of the residue. Physical and chemical characterization of the organic residue and red mud before and after CLG testing showed that some filamentous ash from the organic residue remained on the surface after testing, and potassium from the organic residue migrated onto the surface of the oxygen carrier. The characterization and testing results suggested that CLG may be an advantageous technology to effectively convert an organic waste into syngas and an inorganic waste into a usable product, thereby establishing an approach for beneficial waste resource utilization. [ABSTRACT FROM AUTHOR]

Summary: Due to the gradual depletion of fossil energy and the climate change, many industrialized countries are pursuing a sustainable energy transition, however they choose different pathways. There are such issues on the process of energy transition as the high renewable energy cost and the increase of carbon emissions. In order to ensure the smooth process of energy transition, governments need to draw energy development experience from each other to jointly promote the global energy transition. At the beginning, the recent situations from both energy economy and policy are described in this article with respect to some typical industrialized countries (the G7 countries and China). And then to make comparative analysis more logical, a novel conceptual model ‐ Institution‐Economy‐Technology‐Behavior framework is adopted. Based on this new model, this article makes a comprehensive analysis and discussion on the energy transition of each country. The common points and the differences of energy transition in different countries are summarized to grasp the driven forces of energy transition. And a series of development proposals from the aspects of system, economy, technology and behavior are made to overcome the obstacles of energy transition, ensure the smooth progress of energy transition, and achieve sustainable development. [ABSTRACT FROM AUTHOR]

Summary: Virtual power plants (VPPs) integrate distributed energy effectively and overcome geographical restrictions. This could improve the broad benefits of distributed energy generation. Owing to the intermittency of distributed wind and photovoltaic power at different time scales, when multiple VPPs exist, the interactive energy management strategy should be addressed in terms of two dimensions, namely multi‐operator and multi‐time‐scale (day‐ahead (24 hours), intraday (4 hours), and real‐time (1 hour)). In this study, an interactive energy management framework for multiple VPPs was designed. Furthermore, a three‐level energy‐coordinated management model was employed for multi‐VPP optimal operation including day‐ahead cooperative scheduling, intraday noncooperative bidding, and real‐time cooperative reserve. To solve this model, a chaotic search algorithm was applied to improve the ant‐colony optimization algorithm. The resulting improved chaotic ant‐colony optimization algorithm is proposed to increase the optimization velocity and solution efficiency. Finally, a demonstration project, namely the Sanliduo's VPP in Guangxi Province in China, was taken as an example. The following points can be stressed according to the obtained results: (a) the proposed model implements dispatching‐balance‐reserve interactive optimization such that the output of wind and photovoltaic power increased by 3.42% and 1.85%, respectively, and the revenue increased by 2.53%; (b) the proposed solution algorithm develops the optimal global strategy: compared with the ant‐colony algorithm, the average convergence time increased by 44 seconds, and the supply cost decreased by 1.2%; (c) the robust coefficient provides effective risk decision‐making tools for different types of decision‐makers considering the operational characteristics of VPPs; (d) the openness of power markets is positively correlated to the balance revenue, and higher levels are beneficial for VPPs. Novelty statement: Designed a two‐layer multi‐time scale and multi‐agent energy management framework.Analyzed the interactive game behavior of different operation agents in multi‐time scale.Proposed a three‐level dispatching‐bidding‐reserve energy interactive management model.Constructed a greedy mutation strategy‐based chaotic ant colony group intelligent algorithm.Discussed the influence of various sensitive variables on the optimal energy interactive strategy. Highlights: Designed an interactive energy management framework for the optimal dispatching of virtual power plants (VPPs).Characterize the energy interactive behavior of multiple virtual power plants at multi‐time scale.Proposed a three‐level coordinated optimization model for multi‐VPPs' dispatching‐bidding‐reserve interactive management.Constructed a greedy mutation strategy‐based chaotic ant colony group intelligent algorithm.Calculate the threshold value of key decision variables for getting the optimal energy management strategy. [ABSTRACT FROM AUTHOR]

Summary: High‐capacity LiFePO4 batteries are widely used in public transportation in China. However, overcharge causes serious safety issues, and the nature of the process requires further research. This study investigates an overcharge‐induced thermal runaway of 20 and 24 Ah LiFePO4 batteries under different initial states of charge (SOC) and charging rates. Chemical reactions inside the battery are influenced by the capacity of the battery, that is, a higher capacity induces faster heating and a higher maximal surface temperature than the lower capacity under the same conditions. The temperature curve of low initial SOC battery at low chargingratedoes not change notably. Under other conditions, the thermal runaway exhibits two stages, an initial slow temperature increase (stage I) followed by a rapid temperature increase (stage II). The initial SOC and charging rate are relevant only for the rate of temperature increase in stage I, with little effect in stage II. The study on the temperature characteristics of overcharge‐induced thermal runaway can promotethe safety research of LiFePO4 power batteries. [ABSTRACT FROM AUTHOR]

Summary: There are two types of renewable energy widely used in China: air‐source heat pump and compact all glass solar vacuum pipe water heating systems. To compare the performance of these supply systems, test systems were installed on two adjacent apartment buildings with the same structure, shape, and material. Both sets of equipment were placed in the same environment for the same 31‐day period. The performances and performance parameters of the systems were systematically analyzed. The system energy consumption ratio of the compact all glass solar vacuum pipe water heating system was greater than that of the air‐source system on 81% of the days in the study period. However, extension theory analysis showed that the weight coefficients for the performance parameters of the two systems were equivalent over the study period. The grey relational degree between the system performance and the parameters were also calculated. The grey correlation degrees of the compact all glass solar vacuum pipe water heating system's properties with outlet temperature, inlet temperature, environment temperature, solar radiation, and sunshine time were 0.69, 0.71, 0.68, 0.70, and 0.68; and the grey correlation degrees of the air source heat pump water heating system's properties with outlet temperature, inlet temperature, environment temperature, solar radiation, and hours of sunshine were 0.71, 0.73, 0.71, 0.65, and 0.72. Furthermore, multivariate regression equations were used to study the changes of other parameters when one of the single variables changes. [ABSTRACT FROM AUTHOR]

Summary: In recent years, a substantial number of theoretical, numerical and experimental R&D activities are carried out on the supercritical water‐cooled reactor (SCWR), which proposed as one of the Generation IV nuclear power plants by the Generation IV International Forum (GIF). A research plan has been proposed by GIF on the designing and licensing of a SCWR prototype, which is planned to be constructed and operated in the near future. In the preliminary stage of this research plan a fuel assembly, with its experimental loop, will be constructed and tested in SCWR operating conditions. This article reviews the research activities carried out in the Supercritical Water Reactor Fuel Qualification Test (SCWR‐FQT) project in Europe and Super Critical Reactor In‐Pipe Test Preparation (SCRIPT) project in China. These research activities studied both neutronic and thermal–hydraulic behavior of the test fuel assembly and auxiliary systems of SCWR fuel test facility. CFD simulations, subchannel analysis and system simulations coupled with neutronics code are performed to study the performance of the tested fuel assembly, especially safety related aspects. [ABSTRACT FROM AUTHOR]

Summary: Waste heat recovery helps reduce energy consumption, decreases carbon emissions, and enhances sustainable energy development. In China, energy‐intensive industries dominate the industrial sector and have significant potential for waste heat recovery. We propose a novel waste heat recovery system assisted by a heat pipe and thermoelectric generator (TEG) namely, heat pipe TEG (HPTEG)，to simultaneously recover waste heat and achieve electricity generation. Moreover, the HPTEG provides a good approach to bridging the mismatch between energy supply and demand. Based on the technical reserve on high‐temperature heat pipe manufacturing and TEG device integration, a laboratory‐scale HPTEG prototype was established to investigate the coupling performances of the heat pipes and TEGs. Static energy conversion and passive thermal transport were achieved with the assistance of skutterudite TEGs and potassium heat pipes. Based on the HPTEG prototype, the heat transfer and the thermoelectric conversion performances were investigated. Potassium heat pipes exhibited excellent heat transfer performance with 95% thermal efficiency. The isothermality of such a heat pipe was excellent, and the heat pipe temperature gradient was within 15°C. The TEG's thermoelectric conversion efficiency of 7.5% and HPTEG's prototype system thermoelectric conversion efficiency of 6.2% were achieved. When the TEG hot surface temperature reached 625°C, the maximum electrical output power of the TEG peaked at 183.2 W, and the open‐circuit voltage reached 42.2 V. The high performances of the HPTEG prototype demonstrated the potential of the HPTEG for use in engineering applications. [ABSTRACT FROM AUTHOR]

Summary: This research is motivated by the practice of a well‐known basin—the Yalong River Basin located in the eastern part of the Qinghai‐Tibet Plateau in China, which requires a more reasonable day‐ahead scheduling and operation of a wind‐pumped‐hydro system. Optimal electricity flow remains a widely‐cultivated topic within power system research community since its inception about half‐a‐century ago. In contrast to previous studies, this article proposes a multiobjective multistage nonlinear model to not only for the technical pump‐operating constraints of the coordinated system, but also for lessening the variations on the active power output coming from the intermittence variability of the wind energy resource. Specifically, minimizing the fluctuations of the power output and minimizing the "abandoned rate" of the wind and hydro power are considered two objectives. A state transition equation to compute the energy balance in the reservoir is introduced in the constraint for scheduling the pump‐hydro system. Moreover, the expected operator and chance constraint are used to deal with the stochastic wind energy output. Finally, the scheduling of a wind‐pumped‐hydro system of the Yalong River Basin is proposed as a practical example to illustrate the effectiveness, feasibility, and validity of the proposed model. [ABSTRACT FROM AUTHOR]

Summary: Commercial refrigeration systems in supermarkets are intensive users of energy and CO2 is recognized as the most promising refrigerant such systems. The CO2 parallel compression system has been considered in medium‐ and low‐temperature supermarket refrigeration systems, with auxiliary compressors to enhance system performance. This study is intended to investigate the effects of adding a subcooler in a CO2 trans‐critical supermarket refrigeration system with parallel compression (SPR system). Mathematical models based on mass and energy conservation are built. Optimization is performed for the gas cooler pressure and the receiver pressure for maximizing the coefficient of performance (COP). The performance of the parallel compression system with a subcooler is analyzed and compared to a baseline parallel compression system in different cities of China. A 6.8% average promotion at least in seasonal energy efficiency ratio (SEER) is predicted, and the energy consumption of the whole system decreases 7.1% totally in Haikou. Gas cooler, taking up 63.3% of the total exergy destruction rate, is the key component to increase efficiency through exergy analysis. [ABSTRACT FROM AUTHOR]