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Organizational behavior and stakeholder processes continually influence energy strategy choices and decisions. Although theoretical optimizations can provide guidance for energy mix decisions from a pure physical systems engineeri...
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Organizational behavior and stakeholder processes continually influence energy strategy choices and decisions. Although theoretical optimizations can provide guidance for energy mix decisions from a pure physical systems engineering point of view, these solutions might not be optimal from a political or social perspective. Improving the transparency of our vision sharing and strategy making processes in a systematic way is therefore as important as the actual systems engineering solutions proposed by the modeling tools. Energy trend forecasting and back-casting, scenarios and system analysis have matured into powerful modeling tools for providing advice on optimizing our future energy solutions. The integrated use and iterative improvement of all these approaches can result in energy systems that become better optimized. Such an integrated approach is particularly important to those who have decision-making power over our future energy direction. Some of the challenges and opportunities for energy strategists that strive to promote optimal decisions on our future energy solutions are highlighted in this state-of-the-art review.
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Energy is essential for the creation of wealth and improvement of social welfare; this means that adequate and reliable supply of energy is required to ensure sustainable development. The textile industry is one of the major energ...
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Energy is essential for the creation of wealth and improvement of social welfare; this means that adequate and reliable supply of energy is required to ensure sustainable development. The textile industry is one of the major energy consuming industries and retains a record of the lowest efficiency in energy utilization but energy consumption is in increasing trend, due to modernized machines and continuous usage of the equipments in inefficient operating parameters. The energy cost is around 15% to 20% over the production cost and it stands next to raw material cost. So now a day's area of focus is towards energy consumption at load end and by optimizing the efficiency of the mills. Most of the textile mills have several common features and therefore if the key features for conserving energy are identified then it is quite possible that these can be replicated to the other plants as well. In our research paper we investigated the comprehensive overview of the present energy management strategies in the Ethiopian textile industry and the Implementation Strategies and barriers of Energy Conservation Management Technologies and the driving forces for the implementation of energy efficiency measure.
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The Romanian PV Systems Strategy stated as a target 260 MW installed power by 2020. Here, we discuss the potential of two hypothetical investors (the effective and the distributed) and three more realistic potential investors, i.e...
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The Romanian PV Systems Strategy stated as a target 260 MW installed power by 2020. Here, we discuss the potential of two hypothetical investors (the effective and the distributed) and three more realistic potential investors, i.e. the local administration, the small/medium enterprises (SMEs,) and the large national companies, respectively. From the point of view of evaluating the amount of electrical energy generated, the best strategy is that of the effective investor. However, the best realistic strategy is that of stimulating investments by large companies. The other three strategies give rather comparable (worse) results. The initial investments are similar, in first approximation, for all the five strategies. Without governmental or European subsidies, the project is not economically profitable. In practice, various governmental and European subsidies exist that are different for local administration, SMEs, and national companies, respectively. This makes the strategy based on investments by local administration the most attractive, followed by the strategy based on investments by SMEs. A combination of the three strategies, with focus on local administration, can be recommended for practical implementation.
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Governing climate mitigation is complex, as the recurring gap between policy intentions and actions exhibits. Interventions at the urban scale represent an opportunity to implement energy policy targets. Urban development projects...
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Governing climate mitigation is complex, as the recurring gap between policy intentions and actions exhibits. Interventions at the urban scale represent an opportunity to implement energy policy targets. Urban development projects can function as carrier to implement innovative energy solutions as 'by-product'. To do so, planners must proactively and strategically deploy planning instruments to influence market behaviour, since project realization relies heavily on public-private interaction. This paper explores how local planning authorities use a variety of planning instruments in urban development projects that assist in implementing both planning and energy policy targets. To understand how planning instruments can be deployed deliberately to implement energy policy targets and why a specific instrument mix was chosen, this paper presents a cross-comparison of three urban development projects from Denmark, Germany and the Netherlands, which all successfully implemented innovative energy solutions. Results show that contextual differences in the processes entail the use of specific instruments to implement energy policy targets. However, the deployed instrument types, enabling factors and involved governmental levels in the technology-open processes showed a similar pattern across all three cases.
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The National Strategy for PV systems implementation in Romania sets as target 260 MW installed power by 2020. Here, the potential of the local administration to install a total of 200 MW in eighty localities is studied. Plants bas...
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The National Strategy for PV systems implementation in Romania sets as target 260 MW installed power by 2020. Here, the potential of the local administration to install a total of 200 MW in eighty localities is studied. Plants based on modules consisting of polycristalline PV cells are considered. The modules are mounted at fix tilt angle. Most of the PV plants should have about 6 MW installed power while the country's capital (Bucharest) should have about 47 MW installed power. The total electric energy produced per year by all PV plants is about 0.45% of the country's electric energy consumption in 2009. Building the PV plants yields a dimishment of the GHG emission by about 1.5% of the country's CO_2 emissions in 2007 and the oil saving is about 0.69% of the total yearly consumption in 2009. Governmental or European financial support is needed for successful implementation. The Simple Payback Period may range between about 43 years (no financial support) and less than 4 years (when the equipment is obtained by using non-reimbursed financial resources).
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Fuel cell durability and vehicle operating cost are the main optimization goals of energy management strategy (EMS) for fuel cell hybrid electric vehicles (FCHEV). In this paper, a series fuzzy control strategy (SFCS) is proposed ...
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Fuel cell durability and vehicle operating cost are the main optimization goals of energy management strategy (EMS) for fuel cell hybrid electric vehicles (FCHEV). In this paper, a series fuzzy control strategy (SFCS) is proposed to decrease the load changing rate of fuel cell system (FCs). The test bench is used to obtain the output characteristics and load changing capacity of FCs. In order to increase the driving mileage and to eliminate the uncertainty of manual experience in fuzzy controller, particle swarm optimization (PSO) is used to optimize the subjection function distribution and rule weights of fuzzy control, and the evaluation function is constructed by operating cost. Based on the experiment data of FC and battery, the model of the vehicle and strategy are constructed in the software environment, and the optimization result is obtained through simulation. The results show that the FCs load changing rate is reduced and limited to the range of change capacity through the SFCS, while the durability of the fuel cell is optimized. The SFCS optimized by PSO (PSFCS) increases the driving mileage. Under WLTC and UDDS conditions, mileage has been increased by 11.2 % and 8.79 % respectively.
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This paper provides guidelines which may be useful for the implementation of the Romanian PV system Strategy. Four solutions for PV module orientation were analyzed: (1) fixed optimum tilt angle, (2) single-axis azimuth orientatio...
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This paper provides guidelines which may be useful for the implementation of the Romanian PV system Strategy. Four solutions for PV module orientation were analyzed: (1) fixed optimum tilt angle, (2) single-axis azimuth orientation; (3) single-axis elevation orientation and (4) two-axis orientation. The fixed module at optimum tilt angle collects 14-17% more solar energy than a horizontal module. The optimum tilt angle ranges between 32° in the South and 40° in the North of the country. The difference between the performance of the two single-axis orientation systems (2) and (3) is small. Both systems provide 23-25% more electric energy than fixed modules. Two axes orientation generates 27-30% more electric energy than fixed modules. Modules based on the four types of cells have been considered for a PV plant of given installed power: (1) Poly Si; (2) Mono Si; (3) CdTe and (4) CuInSe. The smallest and largest collection surface areas correspond to Mono Si and CdTe, respectively. The energy generated by all types of modules is comparable, with the highest and lowest values being associated to CdTe and CuInSe cells, respectively. The limited transport capacity of the existing electric grid in South-East Romania puts an upper bound on the number of PV systems to be carried out in the near future.
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In building HVAC systems, a chilled water flowmeter is an important sensor. Its reading can be used to measure the real-time cooling load, which is a critical variable for the automated control of building HVAC systems, especially...
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In building HVAC systems, a chilled water flowmeter is an important sensor. Its reading can be used to measure the real-time cooling load, which is a critical variable for the automated control of building HVAC systems, especially central chiller plants. To maintain accurate reading data, fault detection and diagnosis (FDD) of flowmeters are necessary. The available FD/FDD methods for chilled water flowmeters have several common disadvantages: (1) high requirements on sensor integrity: multiple sensors are usually involved in the construction of energy balance models; (2) complex methodology: the fault of any monitored sensor could trigger a detection hit, and a diagnosis procedure must be used to isolate the faulty sensor; and (3) the more sensors that are involved, the more difficult it is to collect fault-free historical data for the establishment of a fault-free benchmark. To address these problems, a user-friendly fault detection (FD) method for building chilled water flowmeters is proposed in this study. The proposed method requires three types of variables to function: the pump frequency, the pump power, and the measured chilled water flow rate on the header pipe. The real-time pump frequency and electrical power data that are collected by VFDs/power meters are used to estimate the true value of the chilled water flow rate with random forest regressor. An auxiliary alarm rule is proposed to tackle the tradeoff issue between detector sensitivity and false alarm rate. Field data of a real HVAC system are used in a case study to evaluate the performance of the proposed method in comparison with three existing FD methods. The results of the validation case study suggest that compared to existing FD methods, which are based on the physical pump model, ensemble learning and clustering techniques, the proposed method could realize higher hit rates and higher alarm rates when confronting different faults (bias, noise and drift) at various levels. Besides, due to the proposed alarm rule, false alarms caused by occasional data errors are completely evaded. Sensitivity analysis to the proposed method indicates that the random forest with default hyperparameters is good enough for the FD task. In brief, the good features of the proposed method (i.e., the simple workflow, low sensor requirements, accessible robust input variable data, handy estimation model, auxiliary alarm rule with tight detection threshold) render the proposed method feasible and user-friendly for engineering practice.
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The rapid development of intelligent and connected technologies is conducive to the efficient energy utilization of hybrid electric vehicles (HEVs). However, most energy management strategies (EMSs) with optimized, intelligent, an...
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The rapid development of intelligent and connected technologies is conducive to the efficient energy utilization of hybrid electric vehicles (HEVs). However, most energy management strategies (EMSs) with optimized, intelligent, and connected functions have not been directly applied to such vehicles because existing technical conditions cannot meet the theoretical requirements of complex EMSs. Therefore, based on the mapping rela-tionship between the information decision-making ability and the energy management effect, this study is the first to propose four development stages of HEV energy management practical application as follows: energy management based on instantaneous driving cycles (Stage 1 or S1); energy management based on forward driving cycle prediction (Stage 2 or S2); energy management based on global driving cycle prediction (Stage 3 or S3); and energy management based on autonomous velocity planning (Stage 4 or S4). The key technologies of each development stage are not independent, i.e., they complement each other in the process of practical application development. Furthermore, realizing energy management practical applications not only requires novel algorithm models but also involves several challenges such as acquiring and processing multi-source in-formation, predicting the vehicle power demand in the spatial-temporal domain during travel, and determining the vehicle control characteristics and ability. Finally, according to the development goals of energy manage-ment, this study proposes an implementation framework for HEV energy management in higher development stages, namely cooperative vehicle-edge-cloud for intelligent energy management, i.e., CVEC-IEM, which ex-ecutes information decision tasks on different computing platforms and realizes interconnection and interaction to provide development directions and goals for the efficient utilization of energy and successful deployment of HEV practical applications.
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This paper presents a real-time and approximately optimal energy management strategy (EMS) based on Pontryagin's minimum principle (PMP), considering both fuel economy and power source durability. To develop the target strategy, p...
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This paper presents a real-time and approximately optimal energy management strategy (EMS) based on Pontryagin's minimum principle (PMP), considering both fuel economy and power source durability. To develop the target strategy, performance degradation models are built for two power sources: a proton exchange membrane fuel cell and a lithium ion battery. This study provides an online co-state updating method for uncertain driving cycles. The method allows the battery's state of charge to be controlled within a certain range and determines the nearly optimal hydrogen consumption. Furthermore, by incorporating a fuel cell power variation limiting factor with a weight coefficient into the PMP to suppress power changes, the durability of the fuel cell can be improved. The average daily operating cost (calculated based on the fuel consumption and power source degradation) is used to evaluate the tradeoff between fuel economy and power source durability. Simulation results show that the fuel cell durability is improved with a slight increase in fuel consumption and battery degradation, and that the average daily operating cost is effectively reduced. A comparison with the results obtained by adopting a rule-based EMS and a dynamic programming-based EMS indicate the superiority of the proposed EMS.
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