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Abstract Following time-constraining obligations under 2015 Paris Agreement, nations are racing to integrate more renewable energy generation into their power systems than ever before. While solutions for mitigation of renewable energy negative effects to power system stability exist, they are still complex and expensive. One of the most promising technologies, battery energy storage, is widely advocated, but is still unable to solve basic challenge of renewable energy integration – low inertia and provision of sufficient fault currents. This paper presents a practical enabling technology in a form of synergy between a battery energy system and a synchronous machine, which can support fully renewable power system while providing nominal power system inertia. For simplicity, the case for this technology is presented on an example of an Isolated Power System capable of 100% instantaneous renewable operation for prolonged periods of time. High-speed measurements during both steady-state operation and performance under fault conditions were recorded and presented in the paper. [ABSTRACT FROM AUTHOR]

Abstract Moving away from a centralized diesel generation plant, future isolated power systems will increasingly depend on renewable generation which can be distributed across larger areas, due to lower energy density of renewable resources. In future distributed generation systems, a key enabling technology for operating high renewable energy penetration system will be a high-speed communications infrastructure. This new infrastructure can then be used for real-time power system monitoring and control of customers loads, as well as for control of the distributed generation. Our paper presents the concept of a high-speed wireless network capable of real-time monitoring and control of both loads and distributed generation across an isolated power system. The paper also presented real-world measurements taken during a multi-year operation of an isolated power system, and specifically, presented how utilizing communications networks can prove beneficial to increasing renewable penetration in the system whilst preserving power system stability. [ABSTRACT FROM AUTHOR]

Abstract The use of electric energy substitution technology on the demand side provides a low-carbon solution for energy supply, which is more efficient and environmentally friendly. In order to analyze the economic impact of the indoor temperature set-point on the air-source heat pump heating system considering the thermal comfort, this paper proposed an optimal dispatching method that aims at the lowest daily operating cost. Firstly, a model combined an air-source heat pump heating system and a building was established. Secondly, an optimized dispatching model with the lowest daily operating cost as the goal was built. Finally, a typical case was built and study. And based on weather information released by the Meteorological Station, the system was optimally scheduled at the hour level on a typical day in winter by changing the indoor temperature set-point. Numerical studies demonstrate that the use of the optimized scheduling method proposed in this paper can significantly reduce the electric bill of the air-source heat pump heating system. It will provide customers with a guideline to save electric bill. [ABSTRACT FROM AUTHOR]

Abstract The results of an optimized design of grid-connected renewable energy system for University building are presented in this paper. Integrated modelling, simulation, optimization and control strategies are used to test the performance and select the best hybrid renewable power system. The main objective is to design a grid connected renewable energy system to meet the electric load of the building with high penetration of renewable energy, low greenhouse gas emissions, and low cost of energy. Hourly simulations, modelling and optimization were performed to determine the performance and cost of the hybrid power system configurations using load following and cycle charging control strategies. The results show that the grid-tied solar PV/fuel cell hybrid power system offers a good performance for the tested system architectures. With a solar PV capacity of 500 kW and fuel cell capacity of 100 kW integrated with the grid, the total energy generated from grid-tied renewable energy system to meet the desired load is 26% from the grid (purchase), 42% produced from the solar PV, and 32% from the fuel cell. From the total annual power produced, 95% is used to meet the AC primary load of the building and 5% is the sellback to the grid. The daily performance and electricity generation from the proposed grid-tied solar PV/Fuel cell power system is also presented in this paper. The proposed grid-tied solar PV/fuel Cell hybrid power system with the sale of electricity back to the grid has a high renewable fraction (40.4 %), low levelized cost of energy (71 $/MWh), and low carbon dioxide emissions (133 kg CO 2 /MWh). [ABSTRACT FROM AUTHOR]

Abstract Energy saving is actually recognized as one of the most significant ways to reduce primary energy consumption and pollutant emissions. Due to the remarkable importance of heating systems and heat distribution grids, Siram by Veolia and the University of Parma have developed an optimal control system for District Heating Networks. Usually building control systems are designed to manage plants relying on past experience: the optimal control system described in the paper defines plant management strategy on the basis of the future behavior of the systems and the external environment. The proposed control system has been applied to the heating system and the distribution network of a school complex in Podenzano (Emilia-Romagna region). The district heating supplies heat to three different buildings (primary school, secondary school and sports hall). The heating plant is composed of three generators (two fed by natural gas and one by wooden biomass), a Thermal Energy Storage, two main distribution manifolds (supply and return) and three secondary circuits, which distribute heat to the buildings. In the first part of the paper the control algorithm is described, split into plant simulation models and the optimization algorithm. In the second part, the real application and the new communication architecture applied on site are outlined and, finally, the obtained results are reported highlighting the management strategies of generators and pumps. The optimal control strategy application gave important results in terms of energy saving, in particular the energy supplied to the buildings dropped significantly, this is the result of knowing the building behavior in advance. [ABSTRACT FROM AUTHOR]

Abstract This paper describes a preliminary analysis on the integration of renewable energy systems in smart microgrids. The initial theoretical evaluations are referred to the case study of a laboratory DC microgrid interconnecting: electric mobility, stationary storage systems and renewable energy sources in a smart grid scenario. Specific power architectures for the integration of a 7kWp solar generation system with the considered microgrid are analysed and compared, in terms of efficiency and costs, in order to support the choice and the design of optimal solutions. Modeling and simulations of the related components are carried out in Matlab-Simulink environment in order to evaluate the performance of different embedded maximum power point tracking techniques, working in balanced and unbalanced irradiance conditions for the considered PV generation system. The promising results and the considerations reported in this paper highlight the importance of using the proposed smart power architectures and the related control techniques to support the optimal use of sustainable energy generation systems. [ABSTRACT FROM AUTHOR]

Abstract Economic structure and industrial structure play an important role in attracting the type of FDI. By studying the FDI impact on ecological environment in Shandong province, this paper explored its influence on energy consumption from three aspects: scale effect, structure effect and technology effect. Based on the time series data of Shandong Province from 2000 to 2016, the mechanism of FDI on energy consumption in Shandong Province was studied from three aspects: scale effect, structure effect and technology effect, By combining regression model and simultaneous equations model, the paper studied the magnitude and direction of various effects of FDI on energy consumption in Shandong Province from both qualitative and quantitative analysis. The results showed that FDI had negative scale effect, structural effect and positive technical effect on energy consumption in Shandong province, the total effect was negative. Based on this, the paper put forward the optimization strategy from the perspective of the transformation of new and old kinetic energy in Shandong Province.It provided policy suggestions for the government to implement the transformation of new and old kinetic energy, so as to promote the economic development, industrial structure transformation、upgrading and the transformation of new and old kinetic energy in Shandong Province. [ABSTRACT FROM AUTHOR]

Abstract The main objective of this paper is to present a new and cost-effective Information and Communication Technology (ICT) tool that can lead to efficient energy management in buildings and optimal operation of electricity networks with increased share of Renewable Energy Sources (RES) and Electric Vehicles (EVs). The new ICT infrastructure is based on the Digital Audio Broadcasting (DAB) standard and its interoperability with smart metering technology, Intelligent Transportation Systems (ITS) and Building Automation Systems (BAS). The main idea involves the attachment of a DAB receiver to electric devices (from small household appliances up to EVs and solar systems and other RES). In this paper, the DAB protocol is described, enabling high cyber-physical security. Moreover, the results of addressing a thermostatically-controlled load using DAB-signaling in Switzerland are also presented. The next steps envisioned are i) the validation of the final protocol version and of the DAB receivers for various electric appliances and DR schemes and, ii) demonstration of the new technology in real-life cases through the National DAB broadcaster in Greece. [ABSTRACT FROM AUTHOR]

Abstract The growing interest in green building is driving the development of energy efficiency building models. One of the essential elements is an effective and efficient Energy Management system. Traditionally, the system contains lots of meters measuring each appliance. Non-Intrusive Load Monitoring (NILM) is a technique for estimating power consumption of each appliance by disaggregating the end-use power consumption measured by a single meter. However, existing NILM are facing two main problems: 1) some of the small appliances and the similar appliances cannot have their power consumption estimated, and 2) NILM requires a long learning process, which means that a new learning process might be needed if a new appliance is connected. To tackle these problems, this paper proposes to use Intrusive Signature (IS) and Power Line Communication (PLC) for circuit-level load decomposition. The paper focuses on the development of a device using frequency domain signature as the IS. The prototype is developed and deployed on the circuit. The results show an accuracy between 83% to 93%. [ABSTRACT FROM AUTHOR]

Abstract In this paper, the Yangtze River Delta city group for the study, first, using data envelopment analysis estimates the energy efficiency of the city, and found that the Yangtze River Delta city group showing lower energy efficiency overall. Within the urban agglomeration 26 prefecture-level cities, Zhoushan is the only one achieving relatively effective energy efficiency. The spatial heterogeneity of energy efficiency in the urban agglomeration in the Yangtze River Delta is then measured using the Moran's I index (including local), confirming the existence of low-energy efficiency clusters centered around Hefei and clusters of high-energy agglomeration centers centered around Hangzhou. Then the spatial error model is used to test the various factors that affect the energy efficiency of the urban agglomeration in the Yangtze River Delta based on the circumvention of spatial heterogeneity. The conclusion shows that there is a positive correlation between industrial structure, investment, scale, foreign trade and energy efficiency. Government influence and system is negatively related to energy efficiency. Finally, based on the conclusion, this paper puts forward the policy suggestion of promoting the energy efficiency of the urban agglomeration in the Yangtze River Delta. [ABSTRACT FROM AUTHOR]

Abstract Under the background of energy and environmental pressure, the traditional automobiles directly driven by fossil fuel-based internal combustion engines are facing elimination. Extended-range electric vehicles (EREVs) charged by small internal combustion engines become an alternative choice because EREVs have longer range and higher efficiency than battery-based electric vehicles, such as lithium battery-based vehicles. However, most EREVs still utilizes fossil fuel-based internal combustion engines, which still have significant carbon footprint. To compromise this downside, this paper proposes a hydrogen fuel cell extended-range electric vehicle design using liquid ammonia as hydrogen source, and quantify the energy and materials flows for the design. This paper establishes a conceptual model of the entire vehicle taking a truck as an example. A typical configuration is selected to perform energy flow balance calculation. The dynamic model of the vehicle is further constructed based on the conceptual model. Based on the performance requirements of the vehicle's driving, parameters were determined for the motor system, fuel cell system, battery system and super capacitor system. [ABSTRACT FROM AUTHOR]

Abstract The objective of this paper is to assess the impact on fuel saving and emission reduction of biodiesel for power generation, using a wide range of economic indicators. There are many benefits that countries, especially developing ones can gain from renewable fuels like biodiesel. Apart from the possibilities that opens for economic growth and development across the country, especially for rural communities; opportunities are available for independent power producers to generate power to off-grid users and local businesses. This is only achievable from engines and fuels with good economic performance. This paper analyse the impact of Callophyllum inophyllum (CI) biodiesel on the fuel saving and the carbon dioxide (CO 2) emission reduction, focusing on the application of CI biodiesel in two different systems, namely internal combustion engines in the transport sector and gas turbines in the power sector. The results showed that application of CI biodiesel in the power sector is able to have more significant savings in fuel and reduction in the CO 2 emissions. [ABSTRACT FROM AUTHOR]

Abstract This paper presents a hybrid subjective and objective evaluation method of the equipment for first-class distribution network. Firstly, it analysis the difficulties of the equipment selection in the current first-class distribution network. Secondly, it deeply analysis the influencing factors of equipment selection in the first-class distribution network. The comprehensive evaluation indices system of first-class power distribution network equipment is constructed from five aspects including economy, performance, intelligence, coordination, and standardization of equipment, in order to the features of the equipment for power distribution network, such as diversity of equipment functions, diverse evaluation indicators, various types, and varied access methods. The subjective weighted methods are highly subjective and difficult to fully express the effectiveness of weights for evaluating indicators. The objective weighted methods are easy to lose key information due to limited sample of measurement data. A hybrid subjective and objective weighting method is proposed to combined with principal component analysis and analytic hierarchy process, and the relative entropy principle is used to weight distribution of subjective and objective evaluation results. Finally, the feasibility of the proposed method is verified through the first-class distribution network equipment in a province in southern China. This paper provides reference for comprehensive evaluation of first-class distribution network equipment. [ABSTRACT FROM AUTHOR]

Abstract This paper aims to give comprehensive review on the state of current researches and provide some reference for future research. For this purpose, the paper firstly analyses the evolution of real option theory and method, following with the characteristics of renewable energy investment. Then, the usability of real option to renewable energy investment is discussed, and the diverse applications of real option on renewable energy investment and policy evaluation are conducted. The directions for future researches are also presented in the end. [ABSTRACT FROM AUTHOR]

Abstract Nowadays different kinds of renewable energy resources have got rapid development. For renewable energy planning, it is meaningful to assess the comprehensive performance of different candidate renewable energy schemes and distinguish the optimal. In view of this, based on data envelopment analysis(DEA), this paper presents a comprehensive evaluation method of renewable energy technical plans. Firstly, multiple indexes from different aspects are taken into consideration to establish the index system. And in the index processing stage, intuitionistic fuzzy number theory is adopted to describe the fuzziness and ambiguity in qualitative index and convert it into quantitative calculation. Then, super-efficiency DEA model is used to determine the relative ranking of different plans based on the concept of relative efficiency. Finally, a real case of renewable energy development in 2020 from a province in China is used to illustrate the feasibility and effectiveness of the proposed method in this paper. Results show that this proposed method can overcome the shortcoming of traditional basic DEA model and get more objective evaluation results and provide beneficial references for renewable energy planning and development. [ABSTRACT FROM AUTHOR]

Abstract Renewable energy can reduce greenhouse gas emissions by providing renewable electricity, heating, cooling and transportation. The main disadvantage of renewable energy supply is that once it reached a high share in electricity generation, the intermittency caused by renewable energy sources makes balancing of the energy system challenging. This study answers the question "What is the impact of renewable energy on public investment in R&D of energy storage technologies?" Empirical literature studying investments in renewable energy technologies is abundant, however empirical literature studying investments in energy storage technologies is highly limited. Using annual panel data from 28 OECD countries over the period 1990-2014 this paper provides an empirical evidence on the role of renewable energy deployment on public investments in energy storage technologies. The results of fixed effects estimation provide an empirical evidence that governments from countries with greater share of renewable energy invest more in energy storage technologies. Drawing from the empirical results, this paper provides policy recommendations on the need in investments in energy storage technologies due to a growing supply of renewable energy. Although this paper provides lessons from countries which experienced problems with high share of renewable energy and started to promote energy storage alongside with renewable energy, the results will be useful for policy-makers from developing countries with a growing share of renewable energy in total electricity. [ABSTRACT FROM AUTHOR]

Abstract The year 2020 will be the first year for global stocktake on carbon mitigation, whether the current policies are on track to meet the NDC goals would become a highly focused issue, and further enhancement on national NDCs under long-term climate mitigation target would also attract much attention by then. Comparing the actual CO2 emissions in 2017 and the expected emissions under NDC goals, this paper analyzes the gaps between current mitigation progress and NDC goals for major region including the US, EU, China and India, and energy system optimization has been conducted to explore possible plans to close these gaps. In addition, this paper compares CO2 emission pathways under global NDCs and 2-degree target, pointed that existing NDCs are not enough to realize 2-degree target, by 2030, additional mitigation of about 10 Gt CO2 is required for global energy system, which indicating enhanced NDCs should be designed as soon as possible to reduce risks and cost in long-term mitigation actions. [ABSTRACT FROM AUTHOR]

Abstract IMO issued latest environmental regulations Tier Ⅲ has strengthened the emission standards, in which the NOx emission should be less than 3.4g/(kWh) for marine two-stroke engines (engine speed lower than 130r/min) in NOx ECAs. In order to meet the strengthened emission regulations, EGR and fuel injection strategies have been used in marine two-stroke engines to reduce emissions. In this paper, a full cycle computation fluid dynamics (CFD) simulation model has been established in GT-Power software to study the effects of EGR rate, post-injection and pilot-injection on emissions and overall performance of a low speed two-stroke marine engine. By changing the EGR rates and the degree and mass of the post-injection and pilot-injection, an optimal combination among different fuel injection strategies and EGR rates is proposed in this paper. The results indicate that the degree and mass of injection strategies with EGR play an important role in NOx and soot emissions. The trade-off relationship between NOx and soot is improved by changing the fuel injection strategies with different EGR rates. [ABSTRACT FROM AUTHOR]

Abstract As the major energy consumer and carbon emitter, the power sector accounts for 40% of total carbon emissions in China in 2011. Understanding provincial-level driving mechanisms of CO 2 emissions in power sector is vital for achieving China's national carbon emissions reduction targets in 2030. To understand the critical provinces and driving forces of CO 2 emissions in power sector, this paper firstly derives seven different driving factors based on the logarithmic mean Divisia index (LMDI) decomposition model. The provincial-level CO 2 emissions in thermal power sectors are calculated from 2004 to 2014. Then, we analyze the CO 2 emissions growth ratio of each province, provincial-level change rate of contribution and positive or negative contributions of the emission dynamics for each driving force. The main results show that the power sector of Inner Mongolia and Jiangsu contribute a lot to national CO 2 emissions. The change of CO 2 emissions of power sector is bigger in developing provinces compared to that in developed provinces. Based on provincial the CO 2 emissions changes and total amounts, more carbon emission reduction policy should be implanted in Inner Mongolia, Xinjiang, Anhui, Jiangsu and Ningxia. In addition, the economic scale, industrial intensity and energy intensity are the critical driving forces for total carbon emission. By investigating the critical driving forces and their contributions in critical provinces, this paper aims to provide theoretical foundations for decarbonizing power sector. [ABSTRACT FROM AUTHOR]

Abstract On-load tap changer (OLTC) plays a significant role to regulate the voltage of the power system. Although some time, secondary voltage of an OLTC is pulled down when tappings are raised to restore the voltage level. This situation may finally lead to voltage collapse. To address this problem, the behavior of tap setting of OLTCs is investigated, and critical transformer and its allowed range of tap settings is identified in the paper. This paper also proposes a Taguchi based method to find optimal tap settings of OLTCs including critical transformer to improve the voltage stability margin and decrease the real power loss of the system. The proposed method is tested on IEEE 30-bus system to validate its applicability. [ABSTRACT FROM AUTHOR]

Abstract For the past two decades, extensive research has been conducted to evaluate the performance of urban form scenarios such as sky view factors, solar radiation, or energy performance. Simulation-based performance analysis has been applied for optimizing urban design using multiple performance criteria of energy demands, daylighting, or radiance. Two major limitations exist in the performance evaluation methods of urban design: 1) the number of urban design alternatives or scenarios has been limited, and 2) various performance criteria and metrics have not been assessed synthetically. In this respect, we aim to generate all possible alternatives under constraints such as a city policy or development requirements. This paper addresses the integration of generative design and multi-criteria performance analysis for urban design decision making. The relationships between geometric urban forms and multiple performance criteria are identified. The proposed methodology incorporates the reinforcement learning algorithm, an advanced machine learning technique, along with parametric modeling techniques, to enhance urban design decisions based on various performance criteria. This methodology was tested on the design of an international campus of the Georgia Institute of Technology, located in Shenzhen, China. An algorithm generates numerous geometrical alternatives of campus design under site constraints and development requirements of the campus. Those alternatives are then evaluated based on performance criteria of sky openings, solar radiation, or energy consumption synthetically. The method enables an integrated performance analysis for all possible design under constraints. The paper proposes a data driven urban design approach that connect generative design and multi-criteria performance analyses. The relationships between urban geometric forms and performance criteria function derive guidelines for a sustainable and green campus. In future conduct multivariate analysis to examine the relationships between geometric elements and performance measurement metrics. [ABSTRACT FROM AUTHOR]

Abstract By constructing a dynamic spatial Durbin model based on C-D production function that includes energy consumption and air pollution, this paper explains the driving factors of urban economic output in the "2+26" cities of Beijing-Tianjin-Hebei and its surrounding areas during 2006-2015. The result shows the significant spatial autocorrelation of energy consumption and air pollution in the "2+26" cities. The increase in economic output of neighbouring cities will bring about economic radiation and promote the economic output of the city, which provides strong evidence for the necessity of joint prevention and control policy. Further considering effects of the inputs of neighbouring cities, the paper finds that the driving force of economic increase mainly came from the capital and energy input of the city itself, as well as the air pollution dividends of neighbouring cities. Therefore, Beijing-Tianjin-Hebei and its surrounding areas should make the best of the resource advantages of neighbouring cities to achieve complementarity and coordinated development. Governments should construct comprehensive cross-city air pollution prevention mechanism, such as regional air pollution compensation mechanism and fund for air pollution joint control. [ABSTRACT FROM AUTHOR]

Abstract Shipping is a major contributor to the global CO 2 emissions. In order to reduce the ship emissions, various mitigation strategies have been proposed including technical and operational strategies. As it is usually not possible to implement all these mitigation strategies, it is important to evaluate the efficiency of these strategies. For mitigation strategies evaluation, ship energy systems are often used for assessment from a systems perspective. However, ship energy systems are usually quite complex for analysis. This is because they are constructed by many components and these components may have non-linear correlations. In this paper, a Gaussian process metamodel based method is proposed to evaluate the ship mitigation strategies. This method is much more efficient than directly analyzing the ship energy systems when they are computationally expensive to assess. A ship energy system of a chemical tanker is analyzed in this paper. The results indicate that speed reduction has a large abatement potential and all the considered strategies have correlations with each other. [ABSTRACT FROM AUTHOR]

Abstract The paper reviews the processes of Geodesign, as it is currently used in practice, and explore its capability and limitation to adapt to new smart city design and technology. Predictions about the future city are being attempted based on data that is for all intents and purposes based on the distant past. In the smart city, where data is both ubiquitous and continuous, it is possible to use metadata to quickly gain an understanding of how the future city is designed and how the current urban system can be altered. Existing building energy data of eight housing units in the Sumida neighborhood of Tokyo was collected using smart meters. This data was analyzed to determine how the buildings perform in real-time, compared to how the energy models predict the building performance. This comparison showed that the existing buildings are using more energy than the current models predict. There is potential that better utilizing data can help designers and planners come closer to meeting community goals. There is also potential that as we integrate more smart city technologies into our cities for improving future city model, or the change model in Geodesign. This paper discussed how other variables that can be incorporated into larger-scale problems, in which an object-oriented city design model is proposed based on a network of objects and multiple system boundaries. [ABSTRACT FROM AUTHOR]

Abstract Thermal energy storage (TES) has a crucial role to play in conserving and efficiently utilising energy, dealing with mismatch between demand and supply, and enhancing the performance and reliability of our current energy systems. A competitive TES technology requires a number of scientific and technological challenges to be addressed including TES materials, TES components and devices, and integration of TES devices with energy networks and associated dynamic optimization. This paper concerns mainly about TES materials challenges with a specific focus on using shape stable composite phase change materials (CPCMs) for medium and high temperature application. The paper first briefly reviews the state-of-the-art development of materials research for thermal energy storage. The focus is then on CPCMs for medium to high temperatures applications, covering materials screening, formulation based on molecular modelling validated at a different length scale through experiments, formulation based on chemical and physical compatibility, and manufacture of material modules via innovative use of conventional powder technology. The properties of the materials and materials modules are characterised and analysed with an aim to establish property-structure relationships. This includes a particularly interesting aspect of the motion of PCM and nanoscale objects with the PCMs for heat transfer enhancement during thermal cycling, which explains the mechanisms of the encapsulation of PCMs in the composite. [ABSTRACT FROM AUTHOR]

Abstract This paper reviews different methods for determination of specific heat capacity of lithium-ion batteries. Thermal modelling of lithium-ion battery cells and battery packs is of great importance. The specific heat capacity of the battery is an essential parameter for the establishment of the thermal model, and it is affected by many factors (such as SOC, temperature, etc.). The scientific purpose of this paper is to collect, sort out and compare different measurement methods of specific heat capacity of battery. The advantages and disadvantages of different methods are discussed. The applicability of each measurement method for various battery types and the required experimental conditions are discussed. The factors influencing the specific heat capacity of the battery are also summarized. [ABSTRACT FROM AUTHOR]

Abstract In China, renewable energy is expected to account for a larger proportion of electric power systems although regional and intermittent characteristics have led to enormous unused wind and solar power stations in western and northern China. In the mean-while, there exists a large demand on energy in central and eastern areas. The energy storage capability of hydrogen makes it a significant medium for emerging energy storage systems. But the formidable challenge of hydrogen storage and long-distance transportation restricts its development. To address this issue, this paper proposes a scheme for an ammonia-based energy storage system in which ammonia, an environmentally benign hydrogen carrier, is expected to compromise the conflicts of renewable energy supply and consumption in China. By utilizing abandoned wind power and solar power, we get electrolyze water to generate hydrogen and get air to generate nitrogen. Compositing ammonia with hydrogen and nitrogen using Hubert's method also need much electricity. And the power stored in ammonia can be released in form of thermal energy or electricity when needed. This paper then presents some typical applications of ammonia that can meet people's needs of fuel, power, electricity, and zero-carbon fertilizer. The proposed scheme is particularly useful for storing discarded power in western and northern China in ammonia which can be transported and used in eastern regions without regional and seasonal restrictions. As an extra advantage, oxygen as a side product associated with the production of ammonia may play a significant role in oxygen-riched combustion plants. [ABSTRACT FROM AUTHOR]

Abstract The temperature of exhaust gas can exceed 800K, which is much higher than surroundings. It's easy to demonstrate IR and get bombed. Therefore, it's necessary to lower the temperature of exhaust gas. In this paper, a kind of infrared suppressor which uses engine exhaust to eject cold air and water spray is designed. Water spray is produced by ultrasonic atomization. The mixing process of the ejector is revealed by CFD. CFD results are validated with the experimental values. After validation is satisfied, this paper analyzes the temperature field inside the ejector and compares the performances of ejectors with varying geometries. According to CFD results, a device is made. Test results show that a good performance is achieved: radiation energy is only 36% of the original. [ABSTRACT FROM AUTHOR]

Abstract Quantum dots (QDs) are the potential material for the application in optical thermometry, and have been successfully applied to solar cells, LEDs, bio-labeling, structural health monitoring, etc. In this paper, we study the fluorescence properties of CdSe/ZnS QDs in toluene under the action of heating-cooling cycles. The experimental results show that, in a heating-cooling cycle, increasing temperature causes red-shift of the emission peak and the decrease of the PL intensity, and decreasing temperature causes blue-shift of the emission peak and the increase of the PL intensity. The surface structures of the QDs likely are dependent on the cycle numbers, which cause the change of the excited energy state of the QDs in toluene. The results presented in this paper reveals the strong effects of cyclic temperature on the photoluminescence characteristics of QDs. [ABSTRACT FROM AUTHOR]

Abstract This paper introduces the similarity between the mechanism of carbon trading and blockchain, then it elaborates on the application of blockchain in carbon trading. In corporate carbon trading, blockchain technology can record and transfer information flow reliably, realize point-to-point transactions between suppliers and demanders to achieve "decentralization", help to reduce the entry threshold for the carbon trading market. At the same time, an analysis of social environment for blockchain-based carbon trading on person is made. Finally, the paper confirms the value of "blockchain + carbon trading" and looks forward to the future. [ABSTRACT FROM AUTHOR]

Abstract To match for the different temperature of the geothermal resource and strengthen the flexibility of organic Rankine cycle (ORC), this paper proposes a variable capacity power generation superstructure based on Flash and ORC for geothermal energy. A combined Flash-ORC experimental prototype is established to investigate its performance on both steady and dynamic conditions in this paper. Pressured hot water is adopted as the extensive worldwide existed hydrothermal geothermal resource, eliminating the influence of the used heat transfer oil on evaporating process. The experiment results show that there is an optimal mass flow rate of R245fa under the condition of different heat source temperature; Flash and binary power system dominate the flash-binary power system respectively when the heat source temperature are 120 ℃and 130℃;The isotropic efficiency of modified compressor just between 0.2 and 0.25; the power output of per geofluid mass flow rate are 0.78 kWh·t-1and 1.31 kWh·t-1 respectively when the heat source temperature are 120 ℃and 130℃. [ABSTRACT FROM AUTHOR]

Abstract Wind power, solar power and hydropower can form a good complementary effect in space and time. Research on Wind-Solar-Hydro power generation system has gradually become a hot research topic. In this paper, a large-scale hydropower station in southwestern China and its surrounding wind fields and solar fields are taken as examples to establish an optimal scheduling model with the objectives of maximizing system total power generation, maximizing the minimum monthly joint output of the whole scheduling period, and minimizing the ecological over-and-short discharge. The paper presents a multi-objective dragonfly algorithm base on reference point to obtain the non-dominated solutions in the wet year, normal year and dry year. Meanwhile, the scheduling processes of four representative plans on the obtained Pareto front are selected to analyze its certain practical significance. It is found that the established multi-objective optimal model and the proposed algorithm have certain reference value for the optimal operation of Wind-Solar-Hydro power generation system. [ABSTRACT FROM AUTHOR]

Abstract In this paper, based on the study of the effect of indoor natural ventilation, application of earth-air heat exchanger cooling technology in an office was investigated. Taking an office building in Jinan City as an example, this research analyzed the performance of interactions between earth-air heat exchanger cooling technology and building indoor thermal environments. Indoor thermal environment was analyzed with numerical simulation of computational fluid dynamics, the Airpak software was applied for numerical calculation to gain the indoor temperature field, velocity field and the distribution of the PMV index. In addition, energy utilization efficiency was also analyzed in this paper; results showed that reasonable airflow organization is a significant content in airflow design of office rooms under the small temperature difference of earth-air heat exchanger conditions. This will provide basic reference for design of earth-air heat exchanger cooling system. [ABSTRACT FROM AUTHOR]

Abstract Generally, the hourly average wind speed is used in determining the spare capacity and real-time dispatch in power system, but the actual wind speed on the wind turbine is the actual instantaneous wind speed. An indicator (instantaneous variance) that quantify the variability of wind speed (WS) and wind power (WP) is used in this paper, and the experiments prove the rationality of it. Meanwhile, the relationship between the fluctuation of WS and the fluctuation of WP is discussed by using local maximum and minimum points distributions. According to the methods mentioned in this paper, the index applied to quantification of fluctuation is applicable to the schedule of system spinning capacity and the strong consistency of the fluctuations of WS and WP has been proved. [ABSTRACT FROM AUTHOR]

Abstract To realize the commercialization of SOFC, it must be ensured that it can work efficiently and stably. SOFC fault diagnosis becomes an essential part of the research. Due to the strong coupling of faults in the stack, this paper uses neural network algorithm to detect and diagnose faults. The simulation results verify that through the diagnosis of the test sample, the recognition rate of the test sample by the network is found to be 95%, which explains the neural network fault diagnosis model established in this paper on identifying the normal working state of the stack, the electrode stacking of the stack, and the gas leakage fault of the stack has good effectiveness and accuracy. [ABSTRACT FROM AUTHOR]

Abstract The admittance model for the three-phase AC micro-grid is proposed in the paper considering the imbalance of the local load and active compensation of the multi-functional grid-connected inverter (MFGCI). By adopting complex variables, the model unified the positive-sequence and negative-sequence admittances for both the grid-connected inverter and the load. Moreover, the dq transformation based imbalance compensation algorithm is integrated into the model according to the harmonic linearization principle. The theoretical analysis and simulation verify the accuracy of the proposed admittance model. The analysis also indicates that while the adoption of the active compensation can decrease the imbalance of the system, the magnitude and phase characteristics of the equivalent admittance of the compensated load are significantly changed. The admittance model proposed in this paper can be the foundation work for the system stability study for the AC micro-grid. [ABSTRACT FROM AUTHOR]

Abstract Solid oxide fuel cell is a device that can convert chemical energy directly into electricity. Its advantages, such as high efficiency, low emission, quiet operation, fuel flexibility, bring about the broad application prospect. However, it is difficult to obtain the temperature distribution in the existing planar cross flow solid oxide fuel cell through the experiment. In this paper, a control orient two-dimensional differential equation model is established for a planar cross flow solid oxide fuel cell based on the finite node method, and an iterative algorithm for calculating the real time voltage of the fuel cell is proposed for the model. Based on the model, the temperature distribution of the fuel cell in the test and system configuration is simulated. The simulation results show that the model can reflect the thermoelectric characteristics of the planar cross flow solid oxide fuel cell, especially the temperature distribution of the fuel cell. The SOFC temperature distribution modeling in this paper is helpful for the development of temperature distribution observers and design related control methods in later studies. [ABSTRACT FROM AUTHOR]

Abstract This paper describes an integrated power unit (IPU) supplying bleed air and shaft power for main engine starting, aircraft environment control, and in-flight emergency power demand. The zero-dimension steady-state numerical simulation model of the IPU is built for both the normal air breathing (NAB) mode and the stored energy (SE) mode. The design point of the IPU is set in the NAB mode and the off-design performance calculations are accomplished for both modes. The Altitude-Mach characteristic of the NAB mode and the altitude characteristic of the SE mode are discussed and the fundamental control laws of the SE mode are established to minimize stored air consumption. The overall efficiency of the IPU is illustrated in the paper for the two modes. [ABSTRACT FROM AUTHOR]

Abstract The diversity of both organic fluids and performance criteria makes the selection and evaluation of working fluids for organic Rankine cycles (ORCs) full of challenge. To overcome this challenge, this paper first reports on second-law-based analytical expressions for thermal efficiency and a turbine size parameter, which reveal key dimensionless parameters relating to operating temperatures and thermodynamic properties of organic fluids. This paper systematically screens more than 70 working fluids involving a wide range of physical and chemical properties. This study shows that specific turbine size generally increases with critical temperature, reduced ideal gas heat capacity, and the atom number of working fluids. Different-family fluids may lead to ten-fold relative differences in specific turbine size even though they have the same atom numbers. The thermal efficiency of ORCs appears to be independent of critical temperature, or at most, a weak function of critical temperature for low boiling point wet fluids and other halocarbons. This is a result of Jacob number being independent of or dependent weakly on the critical temperature of organic fluids such as alkanes, alkenes, and benzenes. [ABSTRACT FROM AUTHOR]

Abstract Air pollution and increased CO 2 concentration in atmosphere and other energy related issues caused a transformative shift in energy system which contributes to increased utilization of renewables as alternative to generate green energy carriers. The potential of renewable resources in different region and potential energy conversion have been largely considered by many researcher in many countries. The energy conversion technologies to produce heat, electricity, and transportation fuels have made impressive technical advances. Sweden has also been challenging with mitigation of CO 2 emission and trying to shift into a fossil fuel free system in all energy sectors. This paper deals with the current status of fuel demand and supply in the transport sector in a County in Sweden. A scenario for a fossil fuel free transport sector at a regional level is developed to investigate the potential biofuel production from regionally produced straw. The results and analysis indicate that the potential for cereal based bioethanol production in the region is sufficient to meet the biofuel demand of the County. Using the fallow land for cereal cultivation, it is feasible to shift into a fossil fuel free transportation system where all passenger cars are fueled by bioethanol. The results and finding from the current paper will be used to develop further study on optimization of local biofuel production integrated with CHP plants considering application of other feedstock such as municipal wastes. [ABSTRACT FROM AUTHOR]

Abstract In order to improve the thermal performance of Trombe wall and make its active in a whole year, this paper proposed a novel Trombe wall integrated with double layers phase change material (PCM) named PCM Trombe wall. This paper studied the thermal performance of PCM Trombe wall numerically in winter and summer in Wuhan. The results showed that the PCM Trombe wall can improve indoor overheating in summer, and reduce indoor temperature fluctuations in winter. Therefore, the PCM Trombe wall can improve indoor thermal comfort and reduce cooling/heating load in the whole year compared with the traditional Trombe wall. [ABSTRACT FROM AUTHOR]

Abstract This paper investigates the analysis of a terrain characteristics parameter which is responsible for the accurate wind resource estimation for a site. In this paper, the effect of terrain dependent parameters such as Wind shear exponent, Roughness Index, RIX (Ruggedness Index factor) and roughness length has been discussed for a site in Central India Region. Whole one year measured met mast wind data has been taken using anemometer and wind vane at 10 m and 25 m height respectively above ground level. The digitized elevation and roughness model of the corresponding site shows the roughness class 4 (roughness length 1.2525m). The wind data has been extrapolated up to 80m height by using power and log law models which provide the power density near about 120 W/m2. As per the micro sitting guidelines for the virtual wind farm installation 5D X 7D mapping has been selected which Indicates the total power output by installing 8 Vestas V- 90 1.8 MW wind turbine from WAsP is 31.561 GWh and from windPRO is 28.083 GWh. [ABSTRACT FROM AUTHOR]

Abstract Combined heat and power is utilized to generate electric power and produce thermal energy for various applications. In view of this, we investigate the economic savings and environmental effects of using a co-generation system that is made-up of microturbine (MT) and other auxiliaries instead of using only a gas boiler. This paper addresses the power-scheduling problem among the generating units in a microgrid (MG) system that comprises of photovoltaic (PV), wind turbine generator (WTG), MT, grid and battery storage system (BSS). The optimal operation of the proposed MG system is obtained by considering the demand response, operating costs and other key performance indicators. The objective function of this study is to minimize the cost of energy, NPC, emission, operating cost, fuel cost and grid energy purchase. HOMER software is utilized to accomplish the goal of the research work. In this paper, a model is developed to investigate the performances of the system having considered the economic and environmental significance of utilizing renewable energy resources (RERs) in a MG system. The results of the simulation analysis reveal that the proposed model is cost effective to reduce the operating costs of the MG system with the application of RERs. [ABSTRACT FROM AUTHOR]

Abstract With the rapid development of electronic technology, the use of portable and wearable electronics hasbeen widely. In order to eliminate the dependency of low-power electronic devices on batteries and the associated requirement of periodic replacement, researchers have begun investigating methods of generating energy from ambient sources. An airflow energy harvester for human motion is typically composed of a spring-mass system with an air pump connected in parallel with a spring and a turbine. Recent studies have proposed some airflow energy harvesting devices. However, these studies are focused on structural design and little attention has been devoted to the energy conversion process. There are two processes for energy conversion: human motion to airflow energy, then airflow energy to electricity. Focus on the energy conversion, this paper proposes a way to evaluate the energy of the airflow from the perspective of damping at harmonic excitations. The model of an airflow energy harvester for human motion composed of a spring-mass system with an air pump connected in parallel with a spring and a turbine is built, and the balance force analysis is carried out. Comparing the mathematical models and the force analysis equations, the regular pattern of the damping change of the system during the vibration is defined. The simulation isperformed, the result indicates that the energy of the airflow which the vibration system provides is related to the damping of the system. This paper provides a new method toanalyzethe energy conversion process, which helps to measure the efficiency of the airflow energy harvester preferably. [ABSTRACT FROM AUTHOR]

Abstract This paper presents an optimisation method called the Product-Energy Nexus Cascade Analysis (PENCA), developed based on the principal of Pinch Analysis. Product and energy are both valuable resources that are majorly used in industrial processes. Both product and energy are interdependent where increasing product demand will increase the energy demand and vice versa. In this paper, PENCA is introduced to simultaneously optimise both product and energy system that is interdependent. The methodology applies Cascade Analysis to individually optimise both system. As both systems are interdependent, altering one of the system will result in a change to the other system. An iterative method is then introduced to converge the analysis to obtain the optimal result for both systems. A case study is conducted to prove PENCA methodology, in which biogas is used as cooking gas and used to generate electricity and for a residential area of 500 households. A typical household with a daily electricity consumption of 9 kWh and cooking gas 31.06 kWh is estimated for this study. The power plant will also produce electricity to operate the palm oil mill. The production of biogas requires electricity as well due to the presence of electrical machineries in anaerobic digestion and purification process such as pump and compressor. An overall of 4 iterations were conducted and the final capacity of the anaerobic digester is revealed as 474.180 m3 and the biogas power plant capacity is 1522.769 kWh, the biogas storage capacity is extracted and revealed as 1065.003 m3, while the energy storage capacity is 750.00 kWh. [ABSTRACT FROM AUTHOR]

Abstract The photovoltaic (PV) power generation has randomicity and intermittence due to the influence by meteorological factors and it is of significance to establish a reasonable prediction model for PV power. Since it is tough to get a completely optimal prediction of PV power by a single model due to the existence of uncertainty, the paper considered proposing an ensemble method by integrating various individual models to achieve better accuracy. In this paper, a weight-varying ensemble (WVE) forecasting model is established to improve the precision of the short-term prediction of PV power. First, the extraction of feature vectors was implemented to find out the most important variables which also helps to improve the accuracy through data pre-processing. Second, the weather pattern was recognized and clustered based on a self-organizing feature map (SOM) method. Third, the five min-ahead prediction output was obtained using the WVE model that utilizes an integrated framework of Generalized Regression Neural Network (GRNN), Extreme Learning Machine Neural Network (ELMNN) and Elman Neural Network (ElmanNN), which were assembled by Genetic Algorithms optimized Back Propagation Neural Network (GA-BPNN). Results show that the WVE model achieved a higher accuracy with mean absolute percentage error (MAPE) of 5.17%, 5.26%, 5.49% and 5.82% for four types of data. The GA can be applied to optimization of other weight-varying ensemble problems. [ABSTRACT FROM AUTHOR]

Abstract A novel air source heat pump powered bed-based space radiation heating (ASHP-BBSH) system is reported in this paper. This novel system combines the merits from a Chinese Kang, or a heated bed, widely used in northern rural China and a standard ASHP system, which can provide localized space heating via both convection and radiation to maintain a comfortable indoor thermal environment, at reduced energy use. In this novel bed-based system, a bed is heated and thus used as a radiator for providing space heating at both daytime and nighttime. In this paper, firstly, there is an introduction to the novel ASHP-BBSH system. Secondly, based on the experiment setup dimensions, a numerical model is built with a real size thermal manikin. Thirdly, the thermal environment generated by the ASHP-BBSH system is analysed by Fluent. The numerical results show that the ASHP system can achieve a uniform thermal environment and energy saving potential. [ABSTRACT FROM AUTHOR]

Abstract In this paper, the thermal performance of cliff-side cave and Yaokang was studied by local investigation and area measurement. The results demonstrate that cliff-side cave can significantly improve the indoor thermal environment without any active heating conditions in winter. Average indoor air temperature of cliff-side cave was 8.4 ℃, while average indoor air temperature of outdoor and brick buildings was -0.63 ℃ and -0.26 ℃. The thermal performance of Yaokang and its influence were examined on the indoor heat environment quantitatively, the results indicate that the surface temperature of the Yaokang is affected by the gas flow direction and reduces along with the flue flow direction. In the end, the effect of Yaokang heat to the thermal environment of cliff-side cave dwelling is analyzed. Results show that the indoor air temperature of cliff-side cave with Yaokang heating increased 7.6 ℃. The research of this paper provides academic support for the regeneration design of the cave and improves the comfort level of the Yaokang. [ABSTRACT FROM AUTHOR]

Abstract The work presented in this paper is developed as a part of the Horizon 2020 EU project REFURB. The number of deep energy retrofits is falling behind the EU ambitious targets. The REFURB project aims at finding technical and nontechnical solutions that match the demand and supply side of the residential building renovation market. Due to the multiple significant differences at the national level, compelling offers are developed specifically for each country participant. This paper elaborates only on the Danish approach. The Danish approach to create compelling offers for pre-selected homeowner target groups is based on (I) selection of dwelling segment with high impact and energy saving potential, (II) sequenced approach in creating renovation package solutions, (III) compelling offer to be proposed with specific timing. This paper focuses mainly on the second listed component, namely, development of the renovation package solutions. The paper only briefly highlights the selection of dwelling segment and does not present the creation of compelling offer due to the length of the paper. Initially, developed renovation packages are optimized purely focusing on the least-cost optimal, theoretical, energy savings. As a result, very rational packages were developed that were not met with acceptance from the building sector stakeholders. After several surveys and meetings with renovation market stakeholders such as building owners, energy renovation contractors, financial institutions, and energy consultants, the initial renovation packages were redefined in order to take account for factors such as securing investment in the renovated real estate, comfort, architectural aesthetic, and "low hanging fruit" energy saving solutions. Finally, ten different customized renovation packages were developed ranging between up to 7.500 and 62.000 € and bringing theoretical primary energy savings between 30 and up to 80%. [ABSTRACT FROM AUTHOR]

Abstract In this paper, the optimal design of a hybrid energy plant composed of a solar thermal collector, a photovoltaic panel, a combined heat and power system, an absorption chiller, an air source heat pump, a ground source heat pump and a thermal energy storage is studied. The size of each technology is optimized by applying a model implemented in Matlab® environment. The optimization goal is the minimization of the primary energy consumed throughout the life cycle of the hybrid energy plant by using a genetic algorithm. The primary energy consumed during the manufacturing phase of the hybrid energy plant is represented by the cumulative energy demand and is calculated by carrying out a cradle to gate life cycle assessment. The primary energy consumed during the operation phase is evaluated by simulating the system throughout one year. The cumulative energy demand of each system composing the hybrid energy plant is calculated as a function of the technology size. Therefore, the problem of life cycle assessment scaling of renewable and non-renewable energy systems is also taken into account in this paper. A tower located in the north of Italy is selected as a case study and two different approaches are evaluated. The first approach consists of solving the sizing optimization problem by minimizing the primary energy consumption only during the operation phase, while in the second approach the primary energy consumption is minimized throughout the life cycle of the plant by integrating the life cycle assessment into the optimization process. The results show that, if life cycle assessment is accounted for, the optimal hybrid energy plant configuration is different and a higher primary energy saving (approximately 12%) is achieved. [ABSTRACT FROM AUTHOR]