Energy Efficiency and Rebound Effect:Does Energy Efficiency Save Energy?

The aim of this study is to examine the theoric and empirical literature about “rebound effect”. This study summarizes energy efficiency policy and programs in general and in Turkey. Also it gives defination of the “rebound effect” concept. The rebound effect is related to consumer’s tendency to consume more energy due to economic benefit from efficiency improvement. The ‘rebound effect’ is the focus of a long-running dispute of energy economics but it is very new concept in the most developing countries. In literature according to some economist gains in energy efficiency will also reduce the real per unit price of energy services and hence the consumption of energy will rise and partially offset the initial reduction in the usage of energy sources. However for others size of the rebound effect is too small to take attention. The empirical literature shows that the size of rebound effect can change from country to country and sector to sector.

Study on Energy Issues Regarding Sustainable Economic Development of China

Over the past twenty years China has made astonishing achievements in theenergy domain and the total output of coal,electricity and petroleum ranked respectively thefirst,second and fifth place in the world.China has established a strong energy base and resolvedthe energy supply to most villages and farmers to prop up the development of China''s economy.

Analysis on Energy Development of China

The paper introduces the relationship between energy and economic development first, then, through analyzing the characters of energy consumption all over the world and the basic facts about China＇s energy resources, draws the conclusion that the energy and resources of China are hardly able to meet the national demands, and puts forward the policy orientation for China＇s energy development accordingly. At last, it points out the prospect of China＇s energy industry.

Unit GDP Energy Consumption in 2006:Moving from Increase to Decline

On July 12, Xie Fuzhan, Commissioner of National Bureau of Statistics of China attended the press conference held by State Council Information Office, and delivered the report on China＇s national unit GDP energy consumption in 2006, presenting with major indicators of unit GDP energy consumption both at national and regional levels in the year 2006.

Energy Saving,Environmental Protection:Top Priority in China's Development——Exclusive interview with Dr.Yonglong L,Secretary-general,Chinese Committee for SCOPE(Scientific Committee on Problems of the Environment/ICSU).

Energy saving,emission reduction and economic development are major issues China has to meet in building a harmonious society.On one hand,China should pursue a sustainable,fast and sound economic development,on the other hand,she should try to decrease the overuse of energy resources and the environ- mental problems caused by the rapid economic growth. In this regard,on June 24,the Standing Committee of National People's Congress deliberated the draft of Energy Saving Law,according to which China is to take"resources saving"as a basic national policy.This is a key issue to the long-term benefits of China.With relevant questions,China's Foreign Trade interviewed Dr, Yonglong L(?),Secretary-general,Chinese Committee for SCOPE(Scientific Committee on Problems of the Environment/ICSU).and Research Professor at the Chinese Academy of Sciences. Let's listen to Dr.L(?)'s comments with wisdom.

Environment, Health and Economic Growth： Study on Optimal Energy Tax Revenue Distribution

Under the dual pressures of economic growth and environmental protection,how to curb pollution and raise public welfare without harming the economy or with minimal economic output losses has become a major question facing China in its efforts to transform growth pattern and accomplish economic transition. On the basis of an overlapping generation(OLG) model, this paper introduces the health effects of environmental pollution to systematically discuss the optimal distribution ratio of energy tax revenues in subsidizing household income and emission abatement under given tax rates to reduce the risks of "environment-health-poverty" trap. Our research shows that an optimal distribution ratio for maximizing per capita output or an optimal distribution ratio for maximizing public welfare exists. Based on China's actual parameters, however, this study has found that China's energy tax revenue distribution policy hardly meets the two optimal targets at the same time. Specific distribution ratio is subject to government decision-making preference, and needs to be adjusted according to actual differences.

Real-time Energy Management Method for Electric-hydrogen Hybrid Energy Storage Microgrids Based on DP-MPC

With the increasing presence of intermittent energy resources in microgrids,it is difficult to precisely predict the output of renewable resources and their load demand.In order to realize the economical operations of the system,an energy management method based on a model predictive control(MPC)and dynamic programming(DP)algorithm is proposed.This method can reasonably distribute the energy of the battery,fuel cell,electrolyzer and external grid,and maximize the output of the distributed power supply while ensuring the power balance and cost optimization of the system.Based on an ultra-shortterm forecast,the output power of the photovoltaic array and the demand power of the system load are predicted.The offline global optimization of traditional dynamic programming is replaced by the repeated rolling optimization in a limited period of time to obtain power values of each unit in the energy storage system.Compared with the traditional DP,MILP-MPC and the logic based real-time management method,the proposed energy management method is proved to be feasible and effective.

Prosumer Cooperation Behavior:Implications for Prosumer Community Design

The decentralization of the energy sector＇s infrastructure is commonly understood as an important step towards an efficient and sustainable energy system. However, technical measures only have a limited impact on the systems goals. The decentralization of decision-making, the empowerment of households and the occurrence of prosumer communities require more human-centric approaches to meet future challenges; the application of the subsidiarity principle and decentralization seems inevitable but also unclear in its implementation in an energy system, the cooperation behavior of community members gains in importance and the design of prosumer communities must overcome economic problems. This article emphasizes the human-centered challenges which go along with prosumer communities. We apply economic principles to reveal major problems which go with the shifts in energy-related decision-making towards prosumers and integrate behavioral science for prosumer community design. We highlight the importance of energy as an interpersonal construct; a view on energy which will gain in importance within a prosumer communities shaped network.

Electricity Consumption and Spillover Effects A Dynamic Panel Data Approach

The paper intends to analyze economic factors that influence electricity consumption in the OECD economies. A special interest in this context is given to spillover effects of trade on electricity consumption. For this purpose, a model is constructed that using a dynamic panel study approach. The model is estimated in a GMM framework in which a dynamic procedure is conducted along the balanced growth path for electricity consumption in each economy. In advance, the long run dynamic behavior of prices, GDP, and trade induced spillover variables is determined. In a further step, the short run dynamic mechanism is pursued by estimating the partial adjustment dynamic coefficient on the target level of electricity consumption. The analysis is conducted for industrial, as well as residential electricity consumption. Alternatively, the same procedure is estimated by the application of a fixed period model. The model provides a benchmark tool for electricity policy decisions and for electricity consumption projections.

Frequency control system based on power factor control of asynchronous motor

Deduced the relationship between the power factor (PF) and the angular fre-quency according to the simplified equivalent circuit of asynchronous motor, forming a power factor auto-control system. An anti-interference circuit was also introduced in the middle voltage link of inverter to avoid the shift of the optimum PF point caused by the change of the load and the reliable run of the control system was assured. The experi-ment results show that it has a good self-adaptation in the whole scope of speed ad-justment and an obvious economization on energy while it runs under load.

Modelling and Optimal Design of Hybrid Power System Photovoltaic/Solid Oxide Fuel Cell for a Mediterranean City

This work presents a hybrid power system consisting of photovoltaic and solid oxide fuel cell(PV-SOFC)for electricity production and hydrogen production.The simulation of this hybrid system is adjusted for Bou-Zedjar city in north Algeria.Homer software was used for this simulation to calculate the power output and the total net present cost.The method used depends on the annual average monthly values of clearness index and radiation for which the energy contributions are determined for each component of PV/SOFC hybrid system.The economic study is more important criterion in the proposed hybrid system,and the results show that the cost is very suitable for the use of this hybrid system,which ensures that the area is fed continuously with the sufficient energy for the load which assumed to be 500 kW in the peak season.The optimized results of the present study show that the photovoltaic is capable of generating 8733 kW electricity while the SOFC produces 500 kW electricity.The electrolyzer is capable of producing 238750 kg of hydrogen which is used as fuel in the SOFC to compensate the energy lack in nights and during peak season.

Overheated Investment in China： The Alarm Bell Is Still Ringing

The growth of fixed assets investment in China soared to a high record in the first quarter of 2004 after gross domestic product （GDP） bounced substantially in 2003. A bubble is emerging posing threats to Chinese economic development. In order to cool down the overheated investment, Chinese government should promptly take effective measures in macroeconomic control to limit or guide the red-hot investment in some sectors and slow down its growth, thus implements the changes from administrative-driven investment to enterprise-driven investment and from investment-driven economic growth to consumption-driven growth.

Simultaneous optimization of heat-integrated crude oil distillation systems

Crude oil distillation is important in refining industry. Operating variables of distillation process have a critical effect on product output value and energy consumption. However, the objectives of minimum energy consumption and maximum product output value do not coordinate with each other and do not lead to the maximum economic benefit of a refinery. In this paper, a systematic optimization approach is proposed for the maximum annual economic benefit of an existing crude oil distillation system, considering product output value and energy consumption simultaneously. A shortcut model in Aspen Plus is used to describe the crude oil distillation and the pinch analysis is adopted to identify the target of energy recovery. The optimization is a nonlinear programming problem and solved by stochastic algorithm of particle warm optimization.

Elasticity Ratio of Resource Consumption and the Resource Consumption

Today the resources are becoming scarcer, which should not be regarded as unexhausted any more. Correspondingly, the production would be constrained by the scarcity of resources clearly. Then the economic researchers would pay much more attention to reducing the consumption of natural resources in the future. Therefore this paper brings foreword the conception of elasticity ratio of resource consumption based on the concept of elasticity and analyzes the relationship between the parameters. For the certain relationships between the elasticity ratio of resource consumption and resource consumption, this paper will try to reveal, to keep economy growing while resource consumption reducing, what conditions should be met as to the relationships among resource productivity, its growth rate, energy saving efficiency, economic growth rate and elasticity ratio of resource consumption. This paper proves the relationship between the China＇s energy consumption and economy growth using statistic data from 1978 to 2003.

Energy and economic analysis of a point-focus concentrating photovoltaic system when its installation site varies

The concentrating photovoltaic (CPV) systems are a promising technology to obtain clean energy. However, these systems are not equally convenient worldwide due to different climatic conditions. The main aim of this paper is to analyze energy and economic performances of a point-focus CPV system for a residential user when its installation site varies. Three locations, Riyadh, Copenhagen, and Palermo, characterized by very different weather conditions are chosen. A model that links the electrical power of a triple-junction (TJ) cell with its temperature and concentrated radiation incident on it is experimentally developed to evaluate the energy performance of the CPV system. A comparison of the three localities for typical winter and summer sunny days indicates that the higher values of the TJ cell temperature are reached in summer, over 70°C at Riyadh, and its electrical power is reduced compared to a winter day. In winter, a TJ cell in Riyadh supplies an electric power of about 20% higher than that in other two cities, while in summer, the maximum power is observed at Copenhagen. On the contrary, the electrical producibility also depends on the sunlight daily hours number during the year. Hence, considering the real distribution of direct normal irradiance (DNI) and the environmental temperature for each locality, a CPV system composed of modules of 90 cells adopted for a residential user is sized. The electric producibility of the CPV system, by varying its module number, is evaluated for different localities together with the optimal number of the modules which is able to maximize the investment profitability.

Energy Management System Design and Testing for Smart Buildings Under Uncertain Generation (Wind/Photovoltaic) and Demand

This study provides details of the energy management architecture used in the Goldwind microgrid test bed. A complete mathematical model, including all constraints and objectives, for microgrid operational management is first described using a modified prediction interval scheme. Forecasting results are then achieved every 10 min using the modified fuzzy prediction interval model, which is trained by particle swarm optimization.A scenario set is also generated using an unserved power profile and coverage grades of forecasting to compare the feasibility of the proposed method with that of the deterministic approach. The worst case operating points are achieved by the scenario with the maximum transaction cost. In summary, selection of the maximum transaction operating point from all the scenarios provides a cushion against uncertainties in renewable generation and load demand.