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The Swedish pulp and paper industry (PPI) must increase energy efficiency to remain competitive on the global market, which has experienced entries from countries with cheaper energy and raw material supplies. Interactions among variables for energy use, production, energy management, electricity price and firm characteristics (FC), in different types of mills, i.e., pulp, paper and integrated mills, in Sweden from 2006 to 2015 indicate that correlations among the studied variables were different in different types of mills. This difference between types of mills seemed to originate partly from varying accessibility to production residue that could be used for energy. For all types of mills, variation of electricity prices did not correlate significantly with energy efficiency during the study period. The studied FC were firm's age, number of employees, number of companies in company group, net sales and profit for the year. Energy efficiency was more affected by the variables characterizing energy and production compared to the variables representing FC. This study also suggested presence of possible discrepancies between FC that were perceived as barriers to energy management towards energy efficiency, according to previous studies, and what was shown by the data combining variables representing energy use, production and FC. [ABSTRACT FROM AUTHOR]

This paper presents a comparison between four gasification-based biorefineries integrated with a pulp and paper mill. It is a continuation of 'Transportation fuel production from gasified biomass integrated with a pulp and paper mill - Part A: Heat integration and system performance'. Synthesis into methanol, Fischer-Tropsch crude or synthetic natural gas, or electricity generation in a gas turbine combined cycle, were evaluated. The concepts were assessed in terms of GHG (greenhouse gas) emissions and economic performance. Net annual profits were positive for all biofuel cases for an annuity factor of 0.1 in the year 2030; however, the results are sensitive to biofuel selling prices and CO 2,eq charge. Additionally, GHG emissions from grid electricity are highly influential on the results since all biofuel processes require external power. Credits for stored CO 2 might be necessary for processes to be competitive, i.e. storage of separated CO 2 from the syngas conditioning has an important role to play. Without CO 2 storage, the gas turbine case is better than, or equal to, biofuels regarding GHG emissions. Efficiency measures at the host mill prior to heat integration of a gasification process are beneficial from the perspective of GHG emissions, while having a negative impact on the economy. [ABSTRACT FROM AUTHOR]

Abstract The paper drying process has the highest level of energy consumption in the pulp and paper production process. Analysis and optimization of the energy system during the paper drying process is critical for improving the energy efficiency of the entire paper mill. In the existing model for the paper drying process, the solution requires accurate boundary conditions such as the air temperature and humidity of the pocket area and the cylinder surface temperature, which are very difficult to obtain in the papermaking process. This can result in significant deviations between the model solution and the actual production process. This paper focuses on the single-tier dryer cylinder-based paper drying process that has been widely used with high-speed papermaking machines in recent years. A mathematical model is proposed based on real-time data. The verification via industrial production demonstrates that the proposed model is reliable for the paper drying process. Based on the simulation results, two optimization operations have been proposed. The energy consumption decreases from 1.51 t steam/t paper to 1.44 t steam/t paper, 4.6% of the steam and 1.26 × 106 RMB can be saved for a medium-scale paper mill with the annual production capacity of 105 t paper. Highlights • Mathematical model for the single-tier cylinder based paper drying process is proposed. • Both the steam-condensate system and the paper drying process are considered. • The simulation results are verified by the industrial data from a papermaking enterprise. [ABSTRACT FROM AUTHOR]

Abstract: Energy conservation is a central concern of the current industrial world, where increasing efficient energy usage is the only way of reducing a high energy demand. In the present study the optimization of a pulp and paper mill with a cogeneration plant has been carried out. The optimization was realized with a methodology which includes exergy, exergoeconomics, thermoeconomics and pinch analysis. The proposed methodology was useful in determining not only the best plant operating conditions but also establishing the components or subsystems with the highest irreversibilities. As a result of the study, operation changes in the recovery boiler, the turbogenerator, the thermal treatment and the deaerator were realized. Due to the higher irreversibility in the actual evaporator line, a new line of evaporators was proposed. Also, an innovative heat recycling technology as to the use of heat transformers was proposed in order to reduce waste heat discharged to the atmosphere. The results obtained with the proposed methodology, which integrates the different optimization methods, allowed reaching higher efficiencies and lower operational costs than those obtained with the optimization methods working separately. [Copyright &y& Elsevier]

Abstract Long term electricity consumption forecasting has been extensively investigated in recent years in different countries due to its economic and social importance. In this context, the long term electricity consumption projections of a country or region are highly relevant for decision-making of companies and organizations operating in any energy system. In this paper, it is proposed a methodology that combines the bottom-up approach with hierarchical linear models for long term electricity consumption forecasting of a particular industrial sector considering energy efficiency scenarios. In addition, the Bayesian inference is used for model parameter estimation and, enabling the inclusion of uncertainty in the forecasts produced by the model. The model was applied to the Brazilian pulp and paper industry and it was able to capture the trajectory of the real consumption observed during the 2008–2014 period. The model was also used to generate long term point and probability distribution forecasts for the period ranging from 2015 until 2050. Highlights • Bottom-up Bayesian extension for the long-term electricity consumption forecasting. • The proposed model combines the bottom-up approach with hierarchical linear models. • The proposed model considers energy efficiency scenarios. [ABSTRACT FROM AUTHOR]

Integrating electric vehicles (EVs) into the electric power system poses significant challenges to grid operation and planning due to the potential constraints on the power system. To minimize grid congestion, the best option is to increase the production of photovoltaic (PV) energy for domestic use and EV charging stations. This paper addresses the nexus of technical, financial, and environmental effects of customer involvement in economic development and load management. In this paper, a new model design of solar-powered EV charging stations is proposed and implemented in HOMER Grid, and a case study has explored how economic, technical, and energy management benefits can be achieved through customer energy involvement and the integration of PV-based charging stations. The proposed PV-based charging stations contribute toward the energy management of the region, and the study observes the real-time optimal charging and discharging strategy of PV-based grid-connected charging stations. The case study results show that the investigated area can produce 1,070,804.096 MWh/year of energy through maximum customer involvement, consequently reducing overall energy costs. Moreover, the study demonstrates that the selected region can produce 86,961,688 kWh/year through the PV system, achieving 363,899 charging sessions per year, offering maximum advantages and facilitation for EV charging. The proposed model applicability shows that large-scale customer involvement can bring significant techno-economic benefits and attract regional investments. • This paper proposes a new design of a grid-tied renewable energy system. • It investigates the energy economics and environmental effects for a practical location. • The research examines energy management including PV systems and electric vehicles. • The results of proposed model are compared with other models. [ABSTRACT FROM AUTHOR]

The production of electrical energy is always a substantial contributor to a country's economy; in particular, integrating renewable energy sources into the existing power system has tremendous techno-economic implications. However, the optimal penetration of renewables and dynamic loads management is highly complex while considering the multiple variables, time-varying characteristics, and operational uncertainties. This paper proposes a new model design of a grid-tied renewable system. It investigates energy economics and forecasts for the practical locality of the Muzaffarabad area in Azad Jammu and Kashmir. The proposed research examines the annualized energy estimation concerning varied customer PV system participation. The impact of consumer feedback on energy production is briefly examined. Various aspects, such as energy economics, including annual revenue generation, energy prices, and energy sell-back, are demonstrated in detail. The proposed study also looks at the connection between the rising usage of renewable energy and falling greenhouse gas emissions and energy prices. Moreover, it shows how customer input has altered energy economics via each district taking part in energy sharing. Also, it illustrates the relationship between energy bought and sold and how the grid and PV's share of energy interact. Based on the research study findings, PV systems can provide 61% of the total region's energy needs with maximum consumer involvement. The study found that when PV is integrated at a maximum level, grid energy purchases fall to 52%. Polluting gas emissions were reduced by 64% courtesy of the recommended approach, and energy cost was cut from $0.20 per kWh to $0.09 per kWh. The recommended system produces 81,635,608 dollars in revenue yearly and achieves a renewable part of 46.17% with the highest level of customer interaction. [Display omitted] • This paper proposes a new model design of a grid-tied renewable system. • It investigates the energy economics and forecasts for a practical location. • The research examines annualized energy estimation concerning PV systems. • The results of proposed model are compared with other models. [ABSTRACT FROM AUTHOR]

Abstract In this paper we identify a concept of countries' biomass-related sustainability through a revision of the literature and the opinion of professionals, and identify the main reasons that prevent biomass from being a major source of energy production (adversities and constraints). The Interpretive Structural Modeling (ISM) methodology was used for establishing the causal and hierarchical relationships among the variables linked with the adversities and constraints associated with the production of biofuel from biomass and their impact on countries' biomass-related sustainability. At the base of the concept of biomass related countries' sustainability we identify an important constraint associated with the high energy production costs, but also the necessity of supporting new investments, which will drive technological innovations in this sector and allow for an increase in efficiency. The paper presents an innovative approach to the research of biofuel production from biomass by suggesting not only a concept of countries' biomass-related sustainability but also by exploring causal and hierarchical relationships between adversities/constraints of biofuel production and impact on countries' sustainability. Highlights • We develop a new concept of biomass-based sustainability of countries. • We implement an interpretive structural modeling approach. • We identify government policies and market costs as essential to innovation. • Economic may imply Social Sustainability. • There are interdependencies between Economic and Environmental Sustainability. [ABSTRACT FROM AUTHOR]

Abstract Recently, there is an upsurge interest of using biomass derived char products in various fields, in order to address some of the most urgent energy and environmental problems we are facing today, such as CO 2 emission, energy crisis and environmental pollution. In this review paper, most recent studies on biochar/hydrochar production, characterization and prospective utilizations are summarized. Fundamentals and reaction mechanisms of biochar/hydrochar formations are discussed in detail. The energy balance and economic flexibility of biochar production technology is also analysed. The effects of reaction temperature, feedstock types, and thermochemical conversion modes on biochar are compared. In addition, we highlighted benefits and potential challenges in promoting biochar application in energy and environmental fields, including the applications in adsorbents, precursor of catalysts, soil amendment, anaerobic digestion and composting, and electrochemical energy storage materials. This paper not only summarises recent advances in engineered biochar technology but also demonstrates insights on new directions for biochar research and development in the future. Highlights • Biochar has enormous potential for ever-increasing energy and environmental demands. • Formation, properties and applications of biochar/hydrochar are summarized. • Biochar properties are influenced by temperature, feedstock and conversion modes. • The mechanisms of biochar/hydrochar generation are comprehensively summarized. • Biochar applications in energy, waste management and agriculture are reviewed. [ABSTRACT FROM AUTHOR]

Abstract In this paper, a new version of shuffle frog leaping algorithm (SFLA) which called modified SFLA (MSFLA) is proposed. To drive the proposed method both local and global search mechanisms in the original SFLA are modified. The local search mechanism is modified by introducing the movement inertia equation of particle swarm optimization (PSO). Furthermore, the global search mechanism is modified using the crossover and mutation operators of genetic algorithm (GA). Also, the formulation of the combined heat, emission and economic dispatch (CHEED) problem considering the availability of wind and solar power is presented where the objective functions of the CHEED problem are converted into a single objective function using price penalty function. Then, the proposed MSFLA is employed to solve the problem of CHEED with wind and solar power. To show the effectiveness of the proposed MSFLA, different test systems with different scenarios are used. In addition, the scalability of the proposed MSFLA is tested using large-scale test systems. The results of the proposed MSFLA are compared with those obtained by other heuristic and non-heuristic published methods. The comparison with other methods proves the efficiency and the superiority of the proposed MSFLA over other methods in all scenarios. Highlights • A new version of SFLA is proposed in this paper. • This version is derived by modifying local and global search mechanisms in SFLA. • The proposed method is used to solve the CHEED problem with renewable sources. • The proposed method has been evaluated using different test systems and cases. • Results of all cases show the superiority of the proposed method over other methods. [ABSTRACT FROM AUTHOR]

Abstract This paper proposes a quantity-quality-based optimization method of indoor thermal environment design that emphasizes entransy and exergy analysis. We scrutinized the different focuses of entransy and exergy in examining an energy-related phenomenon or process, and pointed out the need for integrating entransy and exergy for the optimization of indoor thermal environment design. The proposed method contributes to identifying the most energy-efficient solution for attaining the same level of indoor thermal comfort for end users by quantifying the entransy and exergy efficiency of active technologies. With this method, a benchmark technical solution was properly determined and benchmarks for entransy dissipation and exergy loss during the process of thermal environment design were quantified. Entransy dissipation and exergy loss under common technologies were compared with the benchmark values. The concepts of relative entransy savings and relative exergy savings were defined as the evaluation indexes of technical energy efficiency. Referencing winter indoor thermal environment design for residential buildings in hot-summer and cold-winter (HSCW) regions in China, the proposed method was applied to assess the energy efficiency of different heating methods, including an inverter air conditioner, an "air source heat pump + floor radiation," a "wall-hanging gas heater + floor radiation," a "wall-hanging gas heater + radiator," and an oil-filled radiator. This paper recommended that the "air source heat pump + floor radiation" be used for residential buildings in winter in HSCW regions to improve energy efficiency. In addition, the optimization results of the proposed method were compared with that of traditional energy and exergy analysis methods. The results showed that the new method more accurately analyzed the energy flow in indoor thermal environment design, and therefore can serve as an improved way of thinking about follow-up studies on the optimization of heat pump units and the operation strategies of floor radiant heating systems. Highlights • Entransy concept for indoor thermal environment design. • Entransy dissipation and exergy loss in the entire energy flow were quantified. • New energy efficiency indexes-relative entransy/exergy savings were defined. • It contributes to optimizing the design and operation of energy systems. • Five typical heating systems were analyzed. [ABSTRACT FROM AUTHOR]

Abstract The solar chimney is one concept currently explored by scientists and designers for reducing heat gain and inducing natural cooling in both commercial and residential buildings. Solar chimneys can be installed on the building walls and roofs. In this sense, a significant amount of research work has been done on solar chimney since the 1990s. This paper presents an overview of transient mathematical models for solar chimneys with/without a phase change material. The review focuses on the Global Energy Balance (GEB) models and a short description of the main works is reported. The analysis of the literature on the solar chimney modeling using GEBhighlights that the transient mathematical model are scarce, from the authors' knowledge, there are only 24 published works and only six studies incorporated a phase change material (PCM) in a solar chimney. Five steady mathematical models available in the literature were analyzed, as well as the advantages and disadvantages of each model. Based on the analysis, it is concluded that the model - III and model - V are more appropriate to model the transient state with respect to the remaining models, and therefore the unsteady mathematical model –III and model - V were developed and shown. These models are highly recommended to be implemented as a solar chimney model in a Building Energy Simulation (BES) program. Finally, we propose a new transient mathematical model for a double-channel solar chimney, which incorporated a phase change material (PCM). This new mathematical model allows building designers and engineers to predict the potential benefit that a solar chimney with PCMmay have for ventilation. Therefore, this paper would provide a valuable reference for further research into the field of solar chimneys with a PCMand its applications. [ABSTRACT FROM AUTHOR]

Abstract Asia has become a major emitter of carbon emissions. To better achieve emission reduction targets, it is necessary to study the characteristics of carbon dioxide emissions in Asia and their emission reduction potential. Firstly, the gravity movement of Asia's carbon dioxide emissions and its leading forces are explored. Then, the Logarithmic Mean Divisia Index method is applied to find the driving factors governing carbon dioxide emissions. Furthermore, this paper establishes a theoretical model of carbon dioxide emission reduction. At last, the influencing factors are utilized to construct a decoupling index, which is used to describe the dependence of economic development on carbon dioxide emissions. The gravity center for Asia's carbon dioxide emissions was an overall movement towards southwest. However, the gravity center for carbon dioxide emissions per capita was an overall movement towards the southeast. The energy intensity effect was the most factor decreasing Asia's carbon dioxide emissions. Only five countries achieved theoretical reduction of carbon dioxide emissions over 2000–2015. However, three countries were failed to achieve the theoretical reduction of carbon dioxide emissions in this period. The economic development in most east Asia and southeast Asia countries was less dependent on energy-related carbon dioxide emissions over the period 2000–2015. Highlights • The gravity movement of Asia's CO2 emissions and its leading forces were explored. • This paper established a theoretical model of carbon dioxide emission reduction. • This paper constructed a decoupling index. [ABSTRACT FROM AUTHOR]

Abstract Giving policy advice related to climate mitigation requires insights that take both sectoral and technology effects (and their interactions) into account. This paper develops a novel soft-linking method for bridging the gap between sectoral top-down and technology rich bottom-up models. A unique feature of the approach is the explicit modelling of energy service demand in the top-down model, which creates a direct correspondence to the energy service production in the bottom-up model. This correspondence allows us, unlike previous work, to capture the macroeconomic impact of energy system investment flows. The paper illustrates the full-scale application of the method in the Danish IntERACT model, considering the unilateral introduction of coal carbon capture and storage in the Danish concrete sector. The policy leads to a reduction in the Danish concrete production, and in turn, a carbon leakage effect of 88%. Results also underscores the importance of accounting for the macroeconomic impact of energy system investment flows, as this is the source of approximately half of the policy-induced reduction in macroeconomic activity. Highlights • Introduces energy service demands in a computable general equilibrium model. • Identifies a highly consistent method for soft linking a top-down and a bottom-up model. • Highlights the full scale implementation of the method in the Danish IntERACT model. • Demonstrates the impact of energy system investments on the macro economy. • Shows that climate mitigation technologies may lead to significant carbon leakage. [ABSTRACT FROM AUTHOR]

Abstract Exergy-based methods are powerful tools for developing, evaluating, understanding, and improving energy conversion systems. This paper deals with integrated advanced exergy-based evaluations. In addition to conventional methods, advanced exergy-based analyses consider (a) the interactions among components of the overall system, and (b) the real potential for improving each important system component. The main role of an advanced analysis is to provide energy conversion system designers and operators with information useful for improving the design and operation of such systems. Splitting the exergy destruction, the capital investment cost, and the component-related environmental impact associated with each single component of an energy conversion system into endogenous/exogenous and avoidable/unavoidable parts and using a further splitting of the exogenous exergy destruction improves (a) our understanding of the processes that take place, and (b) the quality of the conclusions for improvement obtained from the analysis. This paper discusses the main features and some recent developments in the area of advanced exergy-based methods. Application of the method to a simple air refrigeration machine confirms the correctness of the approach. [ABSTRACT FROM AUTHOR]

Abstract Real-time electricity pricing could promote the adaptation of demand response programs in the presence of price volatility in smart grids. This paper proposes a real-time price-based demand response management model for heat and power consumers. In the proposed demand response program (DRP) the responsive electrical load can vary in different time intervals. In addition, total power and heat demands of the consumer are met, without any curtailment. The price uncertainty is envisaged through robust optimization for minimizing the worst-case electricity and heat demand procurement cost while flexibly adjusting the solution robustness. The proposed model can be easily embedded in the energy management system of the customer equipped with combined heat and power systems (CHPs), a power-only unit, a boiler unit and a heat buffer tank (HBT) and makes it possible to achieve a minimum cost. In this paper, the dual dependency characteristic of the heat and power in different types of CHPs has been taken into account. Furthermore, technical constraints, i.e. minimizing number of start-ups and shut-downs, ramp rate limits and minimum up/down-time limits of generation facilities are satisfied. Numerical simulations confirming the applicability and effectiveness of the proposed model are provided. According to the simulation results, there is a significant increase in the daily cost of the consumer without smart grid technology in comparison with the consumer employing the proposed real-time model. Highlights • A real-time price-based DRP is presented for heat and power consumers. • In the DRP, the responsive electrical load can vary in different time intervals. • The proposed model can be embedded in the energy management system of a customer. • The price uncertainty is considered through a robust optimization model. [ABSTRACT FROM AUTHOR]

Abstract As a potential energy utilization paradigm, power and natural gas coupled system (PGCS) with gas turbines and power to gas (P2G) provides an effective approach to improve the energy efficiency with an environmentally friendly and reliable energy supply. To fully exploit complementary potentialities of PGCS and accommodate wind power with P2G devices under system uncertainties, a novel robust multi-objective power and gas flow (RM-PGF) incorporating a two-stage interval robust dispatch is proposed in this paper. Besides, to achieve a complementary energy utilization with an information privacy and a decentralized autonomy for these two sub-systems, this paper establishes a novel two-layer convex decoupled-synergetic framework for PGCS. In the outer optimization, the original nonconvex issue is convexified into an iterative second-order cone programming (SCOP) through a penalty convex–concave procedure (PCCP). While in the inner optimization, the convexified RM-PGF is solved with three decoupled-synergetic strategies, including alternating direction method of multipliers (ADMM), auxiliary problem principle (APP) and generalized Benders decomposition (GBD) based strategies. Finally, numerical simulations validate the superiority of the proposed RM-PGF with P2Gs for wind power accommodation, as well as the computational efficiency and robustness of these convex decoupled-synergetic strategies PCCP-ADMM, PCCP-APP and PCCP-GBD. Highlights • A robust multi-objective power and gas flow with P2Gs is firstly proposed. • A novel two-layer convex decoupled-synergetic framework is established. • More wind power is accommodated with P2Gs in two-stage interval robust dispatch. • A complementary energy utilization is realized with a decentralized autonomy. [ABSTRACT FROM AUTHOR]

Abstract This paper reports a review of an environmentally clean and efficient source of energy such as solid oxide fuel cell hybrid systems. Due to climate concerns, most nations are seeking alternative means of generating energy from a clean, efficient and environmental-friendly method. However, this has proven a big hurdle for both academic and industry researchers over many years. Currently, practical and technically feasible solution can be obtained via an integration of a microturbine and a fuel cell (hybrid systems). Combining the two distinct systems in a hybrid arrangement the efficiency of the microturbine increases from 25 to 30% to the 60–65% range. Hence, this paper outlines an engineering power generation solution towards the acute global population growth, the growing need, environmental concerns, intelligent use of energy with attendant environmental and hybrid system layouts concerning arising problems and tentative proposed solutions. Furthermore, advantages of a solid oxide fuel cell hybrid systems with respect to the other technologies are identified and discussed rationally. Special attention is devoted to modelling with software and emulator rigs and system prototypes. The paper also reviews the limitations and the benefits of these hybrid systems in relationship with energy, environment and sustainable development. Few potential applications, as long-term potential actions for sustainable development, and the future of such devices are further discussed. Highlights • Environmentally clean and efficient source of energy. • Integration of a microturbine and a fuel cell (hybrid systems). • Fuel cell modelling and SOFC hybrid cycles. • Limitations and the benefits of these hybrid systems in relationship with energy, environment and sustainable development. • Few potential applications, as long-term potential actions for sustainable development, and the future of such devices. [ABSTRACT FROM AUTHOR]

Abstract Addressing environmental concerns alongside economic development and energy transitions is a challenge for all countries and effective policy making requires approaches that can balance all these concerns. In this paper, combining a range of modeling methodologies is proposed as a way of addressing these questions in an integrated manner. The choice of models to be used would depend on the specific characteristics of the system and region being studied. One possible combination of models is discusses in this paper for the specific case of India. The Integrated Modeling Framework (IMF) proposed combines three modeling approaches – i) index decomposition to estimate impacts of structural changes in the economy, ii) constrained optimization to estimate least cost fuel options for the power sector, iii) input-output analysis to estimate economic impacts. The model results indicate that the mode of investment for climate change mitigation is a significant determinant of the impact on economic growth, incomes, and income distribution in India. In some scenarios, higher investments in green energy negatively affects low income households significantly more as compared to other households. The paper also demonstrates how the IMF can be used to determine the reasons for and therefore alleviate the negative impacts. Highlights • An Integrated Modeling Framework (IMF) combining three modeling methods is presented. • IMF built for India, but applicable for other developing countries also. • IMF useful to study balance between energy, environment, economy, and equity. • Negative trade-off between equity and renewable energy transition in some scenarios. • IMF useful for identifying ways to alleviate the negative trade-off. [ABSTRACT FROM AUTHOR]

Abstract In 2017 about 37% of the world's wind turbines and 50% of the world's photovoltaic (PV) panels are installed in China. But at the same time a huge amount of wind power and PV power is wasted mainly because of insufficient flexibility of thermal power which is the dominant source in China's electricity system. This paper aims to assess the flexibility requirements for thermal power plants to accommodate large-scale variable renewable energies (VREs). This paper constructs three scenarios for the reference year of 2030, where VREs account for 16%, 19% and 22% in the electricity system respectively, and simulates corresponding residual load time series (residual load = load − hydropower − nuclear power − wind power − PV power). We find that the current average 1%/min ramp rate of thermal power plants is basically sufficient to deal with ramps in residual load in the future. But the current average 60% minimum load level of thermal power plants has to be improved to 40% or even 30%, otherwise the economic losses of VREs curtailment will be as high as 947.2 × 10 8 – 1632.0 × 10 8 CNY per year in the future. It is necessary and beneficial for the central authority to invest in retrofitting the existing huge thermal power plants to improve their minimum load level. Highlights • This paper simulates the future VREs scenarios for the year of 2030. • 1%/min ramp rate of thermal power is sufficient to follow ramps in residual load. • Minimum load level of thermal power has to be improved to 40% or even 30%. • It is a huge economic benefit to improve minimum load level of thermal power. [ABSTRACT FROM AUTHOR]

Abstract The growing development of gas-fired power plants over the last few decades has enhanced the interaction between power and natural gas sectors. As a result, considering an integrated gas and power network is essential to obtain a more precise and reliable analysis of generation and transmission capacity in the power network. This paper investigates a power generation and transmission expansion planning problem in an integrated and restructured electricity and gas market. To model interactions between the different participants of the markets and to identify the equilibrium point, a mixed complementarity problem approach is applied. This paper exploits Cournot game models to provide a behavioral framework for modeling of imperfect competition among electricity producers. Iran's real natural gas and power systems are used to test the proposed model, and its validation is conducted by comparing the pattern of the model outcomes with Iran's real data. The results indicate that expansion decisions lead to lower electricity price as well as improvement in social indexes such as consumer benefit and social welfare. In addition, it is revealed from the results that higher gas price due to low production capacity can lead to a change in the equilibrium point of the power market. Highlights • Investigating an integrated electricity and gas system by a combined analysis. • Formulating the mixed complementarity problem for the integrated system. • Providing a realistic solution for the expansion planning of Iran's power system. • Power producers' expansion decisions influence other actors' behavior. • Expansion decisions in the power system foster social indexes. [ABSTRACT FROM AUTHOR]

Abstract Current phenol and ammonia treatment process consumes a large amount of hot utilities to recover crude phenol and aqua ammonia, which includes 0.5 MPag steam (2.68 MW), 1.0 MPag steam (10.17 MW), and 2.5 MPag steam (1.97 MW) based on the benchmark treatment capacity of 100 t/h. This paper fixates on the further improvement of energy efficiency by process integration and innovation. A novel integrated process is proposed in this paper to abate utilities consumption. Two scenarios have been analyzed following the Grand Composite Curve. The results show that one of the new integrated processes performs better energy saving efficiency. It requires 53.7% (7.96 MW steam) less hot utility consumption and 57.5% (6.86 MW cw) less cooling water consumption at the expense of 68.7% (662 kW elec) more electricity use, as suggested in simulation results. The estimated cost savings relevant to the improved process is 1.095 million US$/y, and the emission reduction is 5237 t CO 2 e/y. Highlights • A novel integrated thermo-vapor compressors system process is proposed. • The new process decreases hot and cold utilities consumption by 53.7%, 57.5%. • The new process saves 1.095 million US$/y operating cost. • The new process reduces CO 2 emission by 5237 t/y. [ABSTRACT FROM AUTHOR]

Abstract With the revolution of the traditional economic and social pattern based on centralized fossil energy consumption, the regional integrated energy system (RIES) has gained rapid development in recent years for achieving higher energy efficiency. This paper expands the Demand Response (DR) concept to the RIES and presents an optimal operation model of RIES considering the DR mechanism on the energy price. In this paper, a comprehensive DR strategy combining energy price and different loads is firstly developed to exploit the demand flexibility of RIES in the DR model established. Based on the DR modeling of the RIES, an operation optimization model with environmental, economic benefits and energy supply reliability as objective functions has been firstly established in detail. Secondly, a complete scheduling scheme is built based on the energy consumption characteristics and system operation characteristic of the integrated energy system. The model presented could reduce the cost of system without causing a significant amount of environmental pollution, and improve the energy efficiency of the RIES efficiently. Besides, the scheduling strategy proposed could also provide support for the operation strategy of integrated energy system under the energy development. Hopefully, this paper will provide reference for future research and engineering projects on DR programs in the RIES. Highlights • The typical structure of the RIES is introduced. • A DR model suitable for the RIES considering different loads is established. • An optimal operation model of the RIES based on DR is established. • The load in the RIES is affected not only by energy price but also by other loads. [ABSTRACT FROM AUTHOR]

To reduce the dependence on fossil fuel, Process Integration and energy efficiency are crucial in chemical process industry to minimise the consumption of fossil fuels and electricity demand through Heat Exchanger Network (HEN). Pinch Analysis is well established to optimal HEN design to maximize the energy recovery in a process. The stream matches for energy recovery in HEN is important to ensure the temperature potential is not wasted, which the temperature potential could be converted into mechanical work. Therefore, Exergy Analysis has been introduced to work with Pinch Analysis, which ensure the heat recovery stream matches with appropriate temperature differences to minimise the work potential (exergy) loss. This paper demonstrates how Pinch Analysis and Exergy Analysis is simultaneously applied to determine exergy targets (rejection, requirement and avoidable losses) in low temperature HEN. A novel numerical tool known as Exergy Problem Table Algorithm (Ex-PTA), is proposed in this paper as a numerical method to the conventional graphical representation in Extended Pinch Analysis and Design (ExPAnD) method. The proposed tool produces more realistic and achievable results. The net shaft work requirement of the refrigeration system is also determined together with the system COP. This paper explored the effect of setting heat exchangers' minimum approach temperature (ΔT min ) on the exergy targets for low temperature HEN design. The external utility requirement and unavoidable exergy losses increased with ΔT min , while avoidable exergy losses and energy recovery reduced with respect to ΔT min . The net power requirement of the system increased with the ΔT min increment, however, the system COP reduced due to higher increment rate of compression compared to expansion work generation. The optimal ΔT min was determined at 2 °C for heat recovery system in the case study based on super-targeting approach, which considers the total annualized cost, operating cost and capital cost. [ABSTRACT FROM AUTHOR]

Determining the carbon impact of commercial developments is an essential starting point in understanding a company's carbon footprint. It is also integral to the development of a strategy to reduce that impact in a cost effective manner. There are numerous industry standard carbon calculation methodologies. This paper focuses on the application of one such method, the Greenhouse Gas (GHG) Protocol, and applied it to the unusual example of a UK safari park. The safari park management wanted to understand the park's impact on the environment as part of a long-term plan to reduce that impact by identifying realistic carbon reduction solutions. Actual monitored energy data for a twelve-month period were available as part of the analysis. The results of this paper show that the application of the GHG Protocol, in reality, and especially for a non-standard situation, is difficult. Effective performance monitoring is essential to enable transparent recording of data, from which a carbon footprint can be calculated. The methodologies for calculation are relatively straightforward but depend upon available information. Identification of the carbon impact of the development is the relatively easier task - the real challenge is reducing this impact to near zero in a cost effective manner. [ABSTRACT FROM AUTHOR]

This paper introduces a growth model that considers the indicator of economic complexity as a measure of capabilities for exporting the high value-added (sophisticated) products. Empirically, the paper analyzes the effects of the renewable and the non-renewable energy consumption on the economic growth in the panel data of 29 Organization for Economic Co-operation and Development (OECD) countries for the period from 1990 to 2013. For this purpose, the paper considers the panel autoregressive distributed lag (ARDL) and the panel quantile regression (PQR) estimations. The paper finds that not only the economic complexity, but also both the non-renewable and the renewable energy consumption are positively associated with a higher rate of economic growth. [ABSTRACT FROM AUTHOR]

The present paper tackles the issue of allocating economic costs in trigeneration systems including thermal energy storage (TES) for buildings of the residential-commercial sector. As energy systems become more and more complex (multiple resources, products and technologies; joint production; TES) the issue of the appropriate way to allocate the cost of the resources consumed arises. This is important because the way in which allocation is made directly affects the prices of the products obtained and, thus, the consumers' behavior. Thermoeconomics has been used to explain the cost formation process in complex energy systems. In this paper, two issues in thermoeconomics that have not been deeply studied are addressed: (i) the joint production of energy services in dynamic energy systems; and (ii) the incorporation of TES. A thermoeconomic analysis of a simple trigeneration system including TES was performed and the hourly unit costs of the internal flows and final products were obtained for a day of the year. The cost allocation proposal considered that the cogenerated products must share the benefits of the joint production. Regarding the TES, the interconnection between charging and discharging periods was explored, allowing the discharged energy flow to be traced back to its production period. [ABSTRACT FROM AUTHOR]

This paper examines the data-mining and supervised based machine learning models for predicting 1-month ahead cooling load demand of an office building, including the primitive intention of enhancing the forecasting performance and the accuracy. The data-mining and supervised based machine learning models include; regression support vector machine, Gaussian process regression, scaled conjugate gradient, tree bagger, boosted tree, bagged tree, neural network, multiple linear regression and bayesian regularization. The external climate data, hours/day in a week, previous week load, previous day load and previous 24-h average load are applied as input parameters for these models. Whereas, the output of the models is the electrical power required for water source heat pump. A water source heat pump located in Beijing, China, is selected for examining 1-month ahead cooling load forecasting, i.e., from July 8 to August 7, 2016. In this paper, simulations are classified into three sessions: 7-days, 14-days and 1-month. The forecast performance is assessed by computing four performance indices such as mean square error, mean absolute error, root mean square error and mean absolute percentage error. The mean absolute percentage error for 7-days ahead cooling load prediction of the water source heat pump from data-mining based models, Gaussian process regression, tree bagger, boosted tree, bagged tree and multiple linear regression were 0.405%, 3.544%, 1.928%, 1.703% and 13.053% respectively. While, mean absolute percentage error of 7-days ahead forecasting in case of machine learning based models such as a regression support vector machine, Bayesian regularization, scaled conjugate gradient and neural network were 12.761%, 2.314%, 6.314%, 2.592% respectively. The percentage forecasting error index proved that the results of data-mining based models are more precise and similar to the existing machine learning models. The results also demonstrate that the better performance and efficiency in foreseeing the abnormal behaviour in forecasting and future cooling load demand in the building environment. [ABSTRACT FROM AUTHOR]

This paper proposes a global driving cycle construction method based on the real-time traffic information, which can realize online optimal energy management for plug-in hybrid electric vehicles (PHEVs). The construction method is mainly divided into three parts: the construction of velocity segments database; the construction of real-time traffic information tensor model database, and the construction of real-time global driving cycle. For the acquisition of the real-time traffic information, a two-step completion method is adopted to obtain the complete and accuracy traffic information; for the driving cycle construction, the velocity segment database, the road section velocity and the Markov transfer matrix with Monte Carlo are used to generate velocity segments which constitute the global driving cycle. With the updated real-time traffic information, the global driving cycle is reconstructed which further reflect the real-time road condition. The efficient dynamic programming (DP) algorithm is applied to realize online energy management in PHEVs. Its simulation shows that the fuel efficiency improves by at least 19.83% compared with charge depleting and charge sustain (CDCS) control strategy. Finally, the economy driving pro system (EDPS) is presented in this paper, and it contributes 5.79% fuel efficiency compared with non-EDPS. [ABSTRACT FROM AUTHOR]

This paper proposes the use of an electrostatic device to improve the performance of MEMS piezoelectric harvesters in the presence of manufacturing uncertainties. Different types of uncertain parameters have been considered and randomised according to their experimentally measured statistical properties. It has been demonstrated that manufacturing uncertainty in MEMS harvesters results in a lower output power. Monte Carlo Simulation is used to propagate uncertainty through the MEMS mathematical model. It has been found that the uncertainty effects can result in two sets of samples. The first set of samples are those with resonance frequency higher than nominal values and the second set includes samples with resonance frequencies lower than the nominal value. The device proposed in this paper can compensate for the effects of variability in the harvester by tuning the resonance frequency to the nominal design. This device is composed of a symmetrical arrangement of two electrodes, which decrease the resonance frequency from its nominal value. However, achieving precise symmetrical conditions in the device on a micro-scale is not feasible. Therefore, the effects of an unsymmetrical arrangement due to manufacturing variability are also investigated. The device includes two arch-shaped electrodes that can be used to increase the resonance frequency. [ABSTRACT FROM AUTHOR]

Combining cost-optimal solutions to reach nearly zero energy buildings (NZEBs) in compliance with European policies is an ongoing challenge. Energy consumption can be reduced evaluating different configurations at the design stage and implementing the most appropriate solutions according to the building and the location. This paper develops a simulation-based optimization framework of cost-optimal choices and energy efficiency measures for new buildings. It combines energy and cost simulations using a sequential search technique to find the most effective combination of energy efficiency and renewable energy measures starting from a base configuration. The model is applied to a residential building prototype, taking into consideration hourly climatic data, construction methods, cost data and energy consumption. A cost database and a library of potential measures, related to envelope, appliances and systems, have been established and used within the optimization process. The potential impact of climate change on the estimated cooling loads has been included in the calculations. The paper shows the feasibility of European requirements for new NZEBs located in different cities. It describes how to best achieve the NZEB design at the lowest cost in 14 locations across Europe. Results highlight how the cost-optimal measures vary with climate and how in each location final selected options differ. Insulation and building tightness appear essential in colder climates, while efficient appliances and lighting are key measures in warmer locations. A key finding of the research is that a source energy reduction of 90% and beyond is feasible for new constructions in all locations. Results also show how efficient lighting and appliances considerably impact the building energy performance. The importance of integrating renewables and energy efficiency measures is confirmed as crucial to reach the NZEBs target. [ABSTRACT FROM AUTHOR]

Chinese electricity market has undergone twice reforms since 2002. However, the current electricity market is still partially irrational in electricity pricing mechanism. Furthermore, the utilization of renewable energy is inefficient in western regions. From the perspective of market participants, electricity retailers are new entrants in deregulated electricity market. In this spot electricity market, they are faced with various challenges and opportunities. Thus, this paper introduces an inter-regional power transaction model based on bottom-up modeling. There are mainly three parts in this paper: ⑴ It examines the existing problems and achievements in the twice reforms, and introduces the participants of cooperative game in a spot market. ⑵It proposes an inter-regional electricity transaction model to illustrate the new pricing mechanism. ⑶ Based on cooperative game theory, it quantifies how costs, electricity prices and benefits affect the behavior of retailers in a spot market with some reasonable economic assumptions. What is novel about this research is that the proposed transaction model analyzes electricity retailers' behaviors in a spot market. The cooperative game model improves electricity retailer's competitiveness in a spot market, and is of great theoretical and practical significance for the reform and development of China's electricity market. [ABSTRACT FROM AUTHOR]

There is a growing interest in developing Inter-Plant Heat Integration (IPHI) methods for reducing energy consumptions and emissions beyond that of independent plants. However, practical IPHI problems present complexities as boundaries for simultaneous intra- and inter-plant heat integration are considered. Pinch Analysis (PA) can mitigate these complexities by elucidating design insights before developing more detailed inter-plant Heat Exchanger Networks (HENs). In this paper, a novel screening algorithm based on PA and the theoretical maximum inter-plant heat recovery potential Q r e c max is proposed for practical IPHI problems. By using this screening algorithm, a large-scale IPHI problem including multiple plants is divided into several smaller sections with each section including two or three plants. Utilizing this algorithm allows for easier calculation and improved total heat recovery potentials approaching to Q r e c max . The final inter-plant HEN configuration(s) for the segregated IPHI scheme(s) are easily developed separately using PA or Mathematical Programming (MP). Before these two steps, the selection of participating streams for IPHI from individual plants is also recommended. Finally, a mathematical model is used to determine the inter-plant HEN configuration(s) in the companion paper of this study. [ABSTRACT FROM AUTHOR]

An electric aircraft propulsion system utilizes a high efficiency motor to generate thrust for electric aircraft. However, it can be challenging to maintain high efficiency for the fixed pitch propeller, which is commonly used in electric aircraft, through all phases of the flight. This paper investigates the power demands of the electric aircraft during the climb and the cruise phases according to the flight profile, and presents a model to estimate the energy consumption per flight. Simulation results suggest that the efficiency in the climb and the cruise phases can affect the energy consumption of an electric aircraft. Efficiency during the climb phase can have a significant effect on the capacity of the electric aircraft propulsion system. Based on the aforementioned results, this paper proposes a novel approach to achieve high efficiency, in which the optimal efficiency points of the electric aircraft propulsion system in the climb and the cruise phases can be obtained by solving an optimization problem with minimizing the energy consumption per flight as the object function and under the constraints that the climb and cruise phases must be successful. For testing purposes, the proposed method is adopted to the design of the electric aircraft propulsion system on a specific two-seater electric aircraft. Experimental results obtained from real flights suggest that the proposed method can reduce the energy consumption of the electric aircraft by over 10%, while reducing the capacity demand for the electric aircraft propulsion system. [ABSTRACT FROM AUTHOR]

The paper presents an exergo-economic based design and analysis of a forward-feed multi-effect mechanical vapor compression desalination system. The analysis is focused on estimating the energy consumption, exergy destruction, Second Law efficiency, and product cost for a different number of evaporation effects. In addition, a detailed heat exchanger design is also presented to estimate the heat transfer coefficients, areas, and pressure drop in the evaporators and feed preheaters. Finally, the cost flow diagram is provided to highlight the monetary cost of each stream as well as product cost which is compared with a conventional method. The values of specific energy consumption, Second Law efficiency and product cost from the current analysis are observed to be ranging from 7.67 to 11.36 kWh/m 3 , 7 to 11%, and 0.86 to 1.19 $/m 3 , respectively. Furthermore, the effect of a number of evaporators, compressor efficiency, evaporation temperature, interest rate, cost index factor and unit electricity cost on the plant performance is also discussed in the paper. [ABSTRACT FROM AUTHOR]

Application of compressed natural gas in public transportation has attracted environmental and social attentions worldwide for natural gas' low air pollutants emission, low cost, and availability. Constructing a suitable compressed natural gas network for public transportation in a city has thus become an important topic for the theory and practice of applying the compressed natural gas, which is considered as a key measure to solve the energy crisis and city congestion. The present paper proposed an integrated decision-making process of compressed natural gas siting for public transportation based on the method of multi-objective optimization, fuzzy evaluating, and radar charting. Multi-objective optimization is used to find the initial feasible solution under the city's requirement in economic, availability, safety and so on. Fuzzy evaluation then provides the criteria of decision-making. Radar charting presents a clear vision of all the candidate solutions for decision-making based on the different feature of the city condition. To illustrate the proposed process, the present paper takes the city of Wuhan, China as the case study. [ABSTRACT FROM AUTHOR]

The paper addresses the issue of the transition from a traditional electrical system without automation to a newer active and smart system allowing the possibility of implementing Demand Side Management policies, for little islands not supplied by the main grid. In particular, the paper focuses on two main topics related to the definition of: • an effective control, monitoring and communication system as a tool for the full exploitation of the opportunities given by Demand Response policies; • some solutions for the automation of the end-users’ electrical installations, in order to offer to the utility flexibility to be used for the improvement of the generation and distribution efficiency. After a brief discussion on the international regulatory framework on automation and ICT applications for power systems, the paper presents a feasibility study, based on the characteristics of the island of Lampedusa, of a hierarchical architecture of a suitable control system and of some DSM enabling solutions for residential end-users. The proposed solutions are defined taking into account some main elements: • distribution grids in small islands are generally equipped with outdated and hardly automatable devices; • utilities in small islands have reduced budget for new investments; • not less important, the most of the inhabitants has low income and unfamiliarity with automation. Therefore, main features of the proposed DSM enabling technologies are low cost and ease of use. [ABSTRACT FROM AUTHOR]

Both energy and water are important resources for human and should be investigated in an integrated way. The paper examines the implications of improving energy efficiency for water resources to contribute to the understanding of energy-water nexus. The paper first develops a mathematical model to link energy efficiency and water withdrawals and consumption. Using the model and the UK energy and water data, the paper then investigates the implications of improving energy efficiency of thermal power technology for freshwater, tidal and sea water in the UK. Results show that when the energy efficiency increases averagely by 10%, the total water withdrawals decrease by 1.65 × 10 6 Megaliter (ML) per year, and the total water consumption reduces by 2.89 × 10 4 ML per year. The saved freshwater withdrawals account for 0.43% of total public water supply in England and Wales in 2013, and could support 138,462 households. The water resources have different sensitivity to the improvement of energy efficiency. The sea water withdrawals are the most sensitive to the improvement of energy efficiency, followed by tidal sea water withdrawals and freshwater withdrawals. Results provide significant informative implications for energy-water nexus, and suggests that it is time to consider improving energy efficiency to address the emerging energy and water challenges. [ABSTRACT FROM AUTHOR]

Distributed energy system (DES) has received much attention in the world to solve the conflict between energy saving and emission reduction. The cutting-edge DES can provide multi-products for the diversity of user, such as cooling, heating, power and even desalination, through a cascade utilization of energy. Furthermore, a large-scale application of renewable energy has been considered in DES with a good interaction to grid. Thus, a dynamic balance between the supply and demand sides is urgently required to maximize the benefit from DES to end-user. All of these new features are extending the technical boundary of the conventional DES, and pose a challenge to flexible mechanism of DES's operation. This paper provides a guided technological tour on the proposed concept--flexible DES (FDES), through a literature research, in terms of features, definition, and capacity adjustment measures. In particular, one kind of FDES featured by the application of mixed working fluid (MWF) is highlighted as the main object in this paper through a summary on separation and mixing mechanism of MWF. An overview about the typical technologies to access such mechanisms, including T junction, ejector, cyclone and distillation, is presented to demonstrate advances and application potential of FDES. Finally, two representative cases from publications are briefly presented and discussed for existing configurations of FDES and possible application of separation and mixing technologies. The literature works in this paper proved a promising application prospect of the new concept FDES due to its significant performance improvement and flexible adjustment function. [ABSTRACT FROM AUTHOR]

This paper presents an approach for designing power and water distribution networks involving the sizing, geographic location, as well as the economic, environmental and social impacts, and taking into account the multiplicity of criteria for the stakeholders involved in the development of operational policies and new facilities. In this paper is presented a method for defining solutions concerning to the design of power and water distribution networks based on a multi-stakeholder environment. A multi-objective model, considering economic, environmental and social factors, is used for illustrating how the different criteria, about priorities of the stakeholders, affect the design of the system and how to propose a solution for achieving a tradeoff between the multiple stakeholders. The proposed method was applied to an electric and water stressed scheme in the north of Mexico, the results show that the minimization of the dissatisfaction of the involved systems can provide an optimal solution that meets the objectives of all stakeholders. [ABSTRACT FROM AUTHOR]

Lack of reliable data often prevents new private investments in renewable energy and government programs in this sphere. The paper offers a novel renewable energy resources system of potentials: energy, resource saving and environmental; better designed and more accurate methods for calculating the future exploitable technical potentials of wind and solar PV energy for a wide range of generating equipment in centralized and distributed power systems, taking into account existing social and environmental limitations. The paper also presents the latest assessments of these potentials for Russia and its 85 regions (in terms of fossil fuel saving and substitution, power and heat production and environmental effects), offering solutions to overcome methodological limitations of previous country-level assessments, such as incomplete or unreliable sources, absence of hourly, daily and monthly assessments, etc. Given the limitations of existing network of national meteorological stations and satellite monitoring systems it was decided to use NASA SSE database as a source of meteorological information. The methodology was validated through a comparative analysis of the data obtained in the course of this study and the data of wind monitoring campaign carried out by a German engineering company in one Russia's region for 18 months using 70 m masts. [ABSTRACT FROM AUTHOR]

In this paper, economic and environmental impacts of energy efficiency programs associated with new and existing buildings are evaluated for the Kingdom of Saudi Arabia (KSA). In particular, the analysis considers optimized designs for new buildings as well as different energy retrofit programs for existing buildings are considered in the bottom-up analysis using archetypical building energy models located in five sites representing a wide range of KSA climates. In particular, the analysis presented in this paper provides specific estimations to the extent of the energy and demand savings that could be achieved in the building sector even under highly subsidized energy prices. It is found that even a basic energy retrofit program using low-cost energy efficiency measures implemented to the existing building stock can provide significant economic and environmental benefits. Indeed, a level 1 energy efficiency retrofit program targeting only the existing residential building stock could reduce electricity consumption by 10,054 GWh/year and peak demand by 2290 MW and carbon emission by 7.611 million tons/year. [ABSTRACT FROM AUTHOR]

This paper sets forth a novel approach to calculate the levelized cost of electricity (LCOE) using a probabilistic model that accounts for endogenous input parameters. The approach is applied to the example of a nuclear and gas power project. Monte Carlo simulation results show that a correlation between input parameters has a significant effect on the model outcome. By controlling for endogeneity, a statistically significant difference in the mean LCOE estimate and a change in the order of input leverages is observed. Moreover, the paper discusses the role of discounting options and external costs in detail. In contrast to the gas power project, the economic viability of the nuclear project is considerably weaker. [ABSTRACT FROM AUTHOR]

This paper investigates the existence of environmental Kuznets curve in Croatia for the period of 1992Q1-2011Q1. To fulfil to goals of the paper, Autoregressive Distributed Lag (ARDL) and VECM method has been applied. Results show the existence of inverted U-shape relation between CO 2 emissions and economic growth in long run that is the validity of EKC. Granger causality based on VECM approach shows bi-directional causality between CO 2 emissions and economic growth in short run and uni-directional causality from economic growth to CO 2 emissions in long run. DOLS and FMOLS results confirm the robustness of long run results. Variance decomposition and Impulse response also show similar results. Beauty of the paper is the consistency of results from different techniques. [ABSTRACT FROM AUTHOR]

The efficiency benefits deriving from the staging of the evaporation process into multiple pressure levels are well known in the field of gas-steam natural gas combined cycles where dual and triple pressure bottoming cycles represent the standard layouts. A similar development of the cycle architecture has not been observed in the field of organic Rankine cycle systems (ORCs). In this paper the dual pressure layout is compared against the single pressure one at subcritical conditions in the utilization of a geothermal heat source in the range 100–200 °C, and considering a set of working fluids wide enough to take advantage of the features of both layouts. The paper proposes simple and unambiguous design guidelines to avoid the unnecessary complexity of the dual pressure layout when the single pressure one already ensures the highest power output, while taking advantage of its full potential in all the other conditions. Results show that the power output gains deriving from the dual pressure configuration are particularly high (up to 29%) at lower geothermal fluid temperatures (100–125 °C) and gradually diminish at higher temperatures (150–200 °C) where some of the selected fluids already obtain the best thermal matching with the heat source in the single pressure configuration. [ABSTRACT FROM AUTHOR]

The practice of providing property tax assessment incentives within the green building sector has been empirically documented to encourage the growth of green buildings. However, no definite and uniform basis has been adopted in the development of these incentive models. Additionally, these incentives require local authorities to bear the implementation costs. Therefore, the aim of this paper is to develop property tax assessment incentive models through the evaluation of their effects on the tax revenue of local authorities and the amount of tax imposed on properties for the taxpayers. There are two incentive models developed in this paper, namely the property tax assessment exemption model and the reduction model. Cost-Benefits analysis between the amount of tax assessment increment and the annual energy savings conveyed by the green envelope components were conducted to determine the appropriate percentage of reduction. Through the exemption model, local authorities do not experience any increment on their existing tax revenue, and taxpayers do not have an increased amount of tax imposed on their properties. However, through the reduction model, local authorities do experience a tax increment of $4 to $9 on their existing tax revenue. As for the taxpayers, annual energy savings conveyed by the green envelope components compensate the amount of their tax increment. [ABSTRACT FROM AUTHOR]

This paper aims to complete and complement the information available on the past trends of thermal energy consumption in residential buildings and its drivers for Europe, as a continent and for the different countries. This paper follows the drivers identified in a previous one for the heating and cooling energy consumption, decomposing this energy demand into key drivers based on a Kaya identity approach: number of households, persons per household, floor space per capita and specific energy consumption for residential heating and cooling. Results show that all drivers did follow a consistent trend at global, regional and country level during the studied period of time, but the heating and cooling energy consumption did not follow the same trend if it was considered at global, regional or country level, showing that the energy consumption is very much influenced by all its drivers and does not follow the same trend as the specific energy consumption. Moreover, similar trends for each indicator can be found when evaluated at country or regional level, therefore as expected when aggregating data trends can be seen but details and particularities (both for the different countries and for the different studied years) are lost. [ABSTRACT FROM AUTHOR]

This paper presents a revised one-dimensional (1D) pulse flow modeling of twin-scroll turbocharger turbine under pulse flow operating conditions. The proposed methodology in this paper provides further consideration for the turbine partial admission performance during model characterization. This gives rise to significant improvement on the model pulse flow prediction quality compared to the previous model. The results show that a twin-scroll turbine is not operating at full admission throughout the in-phase pulse flow conditions. Instead, they are operating at unequal admission state due to disparity in the magnitude of turbine inlet flow. On the other hand, during out-of-phase pulse flow, a twin-scroll turbine is working at partial admission state for majority of the pulse cycle. An amended mathematical correlation in calculating the twin-scroll turbine partial admission characteristics is also presented in the paper. The impact of its accuracy on the pulse flow model prediction is explored. [ABSTRACT FROM AUTHOR]

It is projected that the electric vehicle will become a dominant method of transportation within future road infrastructure. Moreover, the electric vehicle is expected to form an additional role in power systems in terms of electrical storage and load balancing. This paper considers the latter role of the electric vehicle and its impact on the steady-state stability of power systems, particularly in the context of large-scale electric vehicle integration. The paper establishes a model framework which examines four major issues: electric vehicle capacity forecasting; optimization of an object function; electric vehicle station siting and sizing; and steady-state stability. A numerical study has been included which uses projected United Kingdom 2020 power system data with results which indicate that the electric vehicle capacity forecasting model proposed in this paper is effective to describe electric vehicle charging and discharging profiles. The proposed model is used to establish criteria for electric vehicle station siting and sizing and to determine steady-state stability using a real model of a small-scale city power system. [ABSTRACT FROM AUTHOR]

The recent trend in high penetration of renewable energy will lead to a significant mix of renewable technologies in the future power industry portfolio. One important inconvenience of these technologies is their intermittency of power generation. This variability of energy production leads to an increased need of services such as reliability, regulation and transmission congestion. In order to make the electric grid reliable and efficient, system operators have to deploy cost-effective ways to balance supply and demand in real time. Energy storage is considered a viable solution and can mitigate several problems. However, it is still unclear whether or not energy storage will generate enough profit by interacting with energy and ancillary markets. Current economic studies on the energy storage technologies are limited because they do not explore possibilities of using storage in arbitrage and ancillary services in both day-ahead and real time markets. This paper focuses on the economics of energy storage participating in arbitrage and regulation services within different markets. A case study on gravity storage system is used to verify the effectiveness of the proposed operation optimization model. Finally, this paper discusses the value of storage in various grid applications. [ABSTRACT FROM AUTHOR]