Optimal scheduling of a township integrated-energy system using the adjustable heat-electricity ratio model

With the expansion and implementation of rural revitalization strategies, there is a constant need for new energy sources for the construction of new townships. Consequently, integrated energy systems with the interconnection and interaction of multiple energy sources are developing rapidly. Biomass energy, a renewable green energy source with low pollution and wide distribution, has significant application potential in integrated energy systems. Considering the application of biomass energy in ...     

Benguela CommunitylUNAM Wind Power Demonstration Projectm——Experiences in Implementation

The government of Namibia has committed itself to promote the use of economically viable RE （renewable energy） technologies, as a complement to grid electrification, and to improve energy provision to rural areas. This paper presents the implementation of the Benguela Community-UNAM Wind-Power Demonstration Project, which is a community-run wind-power mini-generation pilot plant in Luderitz, Namibia. Luderitz is located in South-Western Namibia along the Namib Desert. The region experiences abundant south-westerly winds and the coastal weather conditions make it a suitable location for wind energy. This project is an initiative from the community of Luderitz and a first of its kind in Namibia. It demonstrates the application of small-scale wind energy systems in Namibia and contributes to the growing national awareness of RE and use of wind power in the country. Through its activities, the project has created a dialogue between the local authorities, business community, schools and the greater community. The balance of the paper discusses lessons learned; envisaged future development plans; highlights technical, administrative and management activities; as well as potential for replication and barriers encountered during the project implementation including institutional constraints. The solution-methods developed are presented and discussed.     

Potentialities of Renewable Energy in Victoria,Australia

In utility power system, electricity demand is being covered largely by fossil fueled power generation, which contributes high level of GHG （greenhouse gas） emission and causes global warming worldwide. In order to reduce GHG emission level, most of the countries in the world targeting towards green energy that is power generation from RE （renewable energy） sources. In this paper, it is considered to study prospects of RE sources in particular, solar and wind in Victoria State which are abundant as compared to other sources of renewable. The wind and solar energy feasibility study and sensitivity analysis has been done for Victoria with the aid of HOMER （hybrid optimization model of electric renewable） simulation software. From the study, it has clearly evicted that wind energy combinational HPS （hybrid power system） has more contribution, and high potential than solar PV （photovoltaic） systems for a particular location. This study also investigates the influences of energy storage in the proposed HPS.     

Social Indicators in Preliminary Studies for the Installation of Solar Panels,Salta, Argentina

More than 10% of the population in Salta is regarded as rural. Many rural areas suffer a shortage of energy, and consequently, possibilities of social and economic development of the inhabitants become reduced. The activation of renewable energy sources in these areas presents inhabitants the advantages to generate their own energy. Dispersed rural communities create small electricity demands that are not considered by suppliers, because they are not profitable. Although thus far, feasibility analyses to install photovoltaic or thermal solar collectors are based on technical reasons, it seems more convenient that, in the future, projects for the installation of technology based on renewable energy should consider social indicators. As a preliminary step to field work is proposed in this paper using an equation that allows us to obtain a value of＂social index＂. With this analysis and the current survey accompanied by the local people, knowledge will be obtained of the real needs of these rural communities. The results show that there is a variation that would allow a classification or ordering of localities. To validate the results obtained is proposed as the next step to perform field work in each of the localities.     

Large Scale Energy Storage for Renewable Energy

<正>As the energy demand and the concern on the environmental impact progressively increase,the renewable energy collected from renewable resources such as sunlight,wind,and tides,plays a more and more important role in providing energy for our daily lives and reducing greenhouse gas emissions. One of the problems associated with the renewable energy sources is their variability. For example,solar and wind power tend to fluctuate based upon whether     

Forward Future

正To meet the progressively increasing demand of energy in this world and counter the effects of global warming and climate change for a sustainable future,renewable energy resources should be the focus while the current primary energy sources of fossil fuel should be utilized as efficiently as possible.     

Energetic Analysis and Working Fluids Selection for a New Power and Refrigeration Combined Ecological System

The main purpose of this study is to analyze the performance of a new system that combines organic Rankine Cycle(ORC) and vapor compression refrigeration cycle(VCRC) for refrigeration and cogeneration. This system uses low-temperature heat sources such as solar energy, geothermal, industrial waste heat and biomass. The novelty of the proposed system manifests itself essentially in: the development of new ORC-VCRC combination architecture, lowering the ORC condensing temperature, the possibility ...     

Electrochemical Energy Storage Technologies and Applications

The current need to fasten the implementation of renewable energies greatly depends on the development of competitive storage devices, and while there is not a single technology which is likely capable to competitively cover the wide range of possible demands, electrochemical technologies are one of the most promising for many of them. For the realization of this promise, new materials fulfilling criteria such as high energy density, high power density, competitive cost, reliability, and environmental compatibility need to be developed in the near future. Electrochemical energy storage devices can be classified into two main technologies： supercapacitors and batteries （including redox flow batteries）. Materials and applications for these technologies are discussed and compared, listing current status, technical and strategic challenges.     

Energetic and Environmental Optimization of the Biomass Using

Biomass energy conversion can be done in several ways-combustion, gasification, pyrolysis or anaerobic fermentation （biogas production）. Each of these technologies has certain advantages and disadvantages from the point of view of energy generation for final consumption. In parallel, each of them has certain environmental impact in terms of emissions. The proposed EU directive prefers utilization of primary energy sources by application of highly efficient co-generation. Such change in assessment of energy effectiveness also means a completely new approach in assessment of current technologies. This report presents a guide for optimization of biomass energy conversion technologies assuming application of this new condition and minimal environmental impact. Specific values of emissions from particular technologies are used for the evaluation.     

Influence of Temperature Difference Calculation Method on the Evaluation of Rankine Cycle Performance简

In the new century, energy and environmental problems are becoming more critical, and the development of natural energy is desired. Low-grade Thermal Energy Conversion （LTEC） is refocused as one of the renewable energy methods. The usefulness of LTEC is expected using hot springs and waste heat. In the case of the Rankine cycle using ammonia as the working fluid, the thermal properties of the working fluid changes in the evaporator. The traditional evaluation method of heat exchanger performance is the LMTD （Logarithmic Mean Temperature Difference） method. On the other hand, the GMTD （Generalized Mean Temperature Difference） method allows the variation of thermal properties in the heat exchanger. The aim of this study is to compare the two methods for the calculation of temperature differences and the corresponding influence on the total performance of the Rankine cycle that is operated using ammonia as a working fluid. As a result, the thermal efficiency of the Rankine cycle is greater than that of the LMTD method. Moreover, the computable range of the GMTD calcula- tion method is less than that of the LMTD calculation method.     

Projected Long-Term Behavior of the CO2 Emission Factor in the Electricity System of Uruguay

Estimating CO2 emission factor of the electricity system is a key aspect in the calculation of the baseline emissions for projects certified as CDM （Clean Development Mechanism）, which replace energy from the grid. Currently, Uruguay is driving the expansion of the electricity system based on domestic renewable energies, in addition to replacing oil-based fuels for others with lower emission factors. This implies a substantial change of the generation park in the next decade and of the associated CO2 emissions. In this paper, a calculation methodology of the baseline emissions is adapted for its incorporation in the software SimSEE （Electric Energy Systems Simulator）, which is used for modeling the Uruguayan electric system, and therefore, allows modeling the current energy generator park and the future one. Using this tool, the CO2 emission factor＇s evolution is evaluated in the 2012-2020 period. The 2020 scenario is based on an optimal expansion of the electric system. The results indicate a strong reduction of the emission factor between 2012 and 2020, going from average values （for 100 simulations） around 0.60 tCO2/MWh to 0.15 tCO2/MWh. In this possible future scenario, CDM certification will probably not act as a strong incentive in Uruguay for the development of projects based on non-traditional renewable energies.     

Performance Assessment of Low-Temperature A-CAES(Adiabatic Compressed Air Energy Storage) Plants

The widespread diffusion of renewable energy sources calls for the development of high-capacity energy storage systems as the A-CAES(Adiabatic Compressed Air Energy Storage) systems. In this framework, low temperature(100°C–200°C) A-CAES(LT-ACAES) systems can assume a key role, avoiding some critical issues connected to the operation of high temperature ones. In this paper, two different LT-ACAES configurations are proposed. The two configurations are characterized by the same turbomachines and ...     

CONTENTS

Based on the systematic research of Shanghai industrial to- tal energy consumption situation and the specific classification of Shanghai industrial energy consumption, this paper analyzes the present situation of Shanghai industrial energy saving as well as its standardization in detail and further puts forward three suggestions for the development of this city＇s industrial energy saving standardization work.     

Flexible HVDC Transformer for Next Generation Renewable Energy Industry

The growing demand on non-fossil fuel energy has escalated the desire for mega-scale renewable energy power generation, which can no longer be satisfied solely by relying on onshore renewable energy power plants. Outcomes from a recent project funded by the Sixth European Union Framework Programme （FP6）, Project ＂Upwind＂ concluded that larger offshore wind turbines （i.e., 〉 10 MW） are feasible and cost effective. It will be beneficial for such future large scale renewable energy power generators （i.e., large offshore turbines） and plant （i.e., large offshore wind farms） to have a dedicated high efficiency, robust, flexible and low cost power collection, transmission and distribution technology. Proposed in this paper is a compact and effective hybrid HVDC （high voltage direct current） transformer that allows realisation of a highly robust and financially rewarding next generation multi-terminal HVDC system for future offshore renewable energy power plant. This concept, potentially, allows the elimination or minimisation of the need for a centralised local offshore HVDC platform or substation in each wind farm, solar farm, or tidal farm. This paper discusses the study outcome of the proposed hybrid HVDC transformer and the application of a multi-terminal HVDC system in the renewable energy industry, compared to the existing HVAC and VSC （voltage source converters） type HVDC systems.     

Numerical Simulation of Multistory Building Fire with Zone—Modeling Method

Based on the basic idea of zone modeling method,a two-layer zone model is developed and programmed to calculate the fire growth and smoke spread in a multi-room buiding subjected to a fire.The related predictive equations,numerical simulation method and sub-models implemented in this model are concisely described.A set of experimental data from Cooper‘s work at NIST for a two-room compartment fire are chosen for comparison with the model and program,and the numerical results fundamentally agree well with the experimental data,Then,an example of numerical calculation of a two-stoy duilding fire is presented,and the relevant output results are given and analyzed.     

Assessing the Public Lighting with Solar Panels in the Sub Saharan Countries in Africa： Yaounde Case Study

Located in central Africa, Cameroon offers a wealth of solar power opportunity. The public lighting in the capital city Yaounde is an example of solar energy promotion. The purpose of this paper is among other things aiming at assessing the solar energy resources of central Africa and making sure it can be used optimally at least for public lighting. Based on the knowledge from data collected and field experience for three years, the authors will assess the implementation of the technology and show how the use of solar energy can solve some problems in the city of Yaounde even when the area is grid connected. This paper will also identify actions for improved access to sustainable, friendly, affordable solar energy services to users, as well as a significant improvement of energy infrastructure and energy efficiency in the city. The authors will also address issues on identified obstacles for the promotion of solar energy in order to help the cities in sub Saharan countries to develop a vision aiming at developing good solar energy policy and better contribute to fight against poverty and climate change.     

Numerical Simulation of Sub-cooled Cavitating Flow by Using Bubble Size Distribution

A new cavitating model by using bubble size distribution based on mass of bubbles is proposed. Liquid phase is treated with Eulerian framework as a mixture containing minute cavitating bubbles. Vapor phase consists of various sizes of minute vapor bubbles, which is distributed to classes based on their mass. The change of bubble number density for each class was solved by considering the change of bubble mass due to phase change as well as generation of new bubbles due to heterogeneous nucleation. In this method the mass of bubbles is treated as an independent variable, in other word, a new coordinate, and dependant variables are solved in Eulerian framework for spatial coordinates and bubble-mass coordinate. The present method is applied to a cavitating flow in a convergent-divergent nozzle, and the two-phase flow with bubble size distribution and phase change was successfully predicted.     

Load Management Scheme Using Air Conditioning Electric Power Consumption and Photovoltaic Power System Generation

In the last few decades, in the world and also in the European Union, considerable resources had been invested in the rapid development of renewable energy sources and distributed generation in general. At the same time, power consumption is continuously increasing, and consumers are becoming more complex, which ultimately requires new investments in the distribution network. Concept of smart grids is generally accepted as a possible solution. Smart grid is a concept with many elements, where monitoring and control of every element in the chain of production, transmission, distribution and final consumption enable much more efficient delivery and use of electricity. One of the elements of smart grid efficiency is the ability of real-time demand-supply balancing. This balancing is carried out by monitoring of consumption and redistribution of electricity among individual end users, according to their needs. The aim of this paper is creating algorithm for real-time load management using power measurements. Algorithm for real-time load management at the ETFOS （Faculty of Electrical Engineering in Osijek）, Croatia is created based on measurements of photovoltaic power plant production, the power consumption of air conditioning system and the faculty building total electricity consumption. Expected result of real-time re-dispatching of air conditioners consumption, depending on the level of electricity production in photovoltaic power plant is decreasing peak demand of the faculty.     

Finite Set-Model Predictive Current Control of Three-Phase Voltage Source Inverter for RES （Renewable Energy Systems） Applications

This paper focuses on a combination of three-phase VSI （voltage source inverter） with a predictive current control to provide an optimized system for three-phase inverters that control the load current. A FS-MPC （finite set-model predictive control） strategy for a three-phase VSI for RES （renewable energy systems） applications is implemented. The renewable energy systems model is used in this paper to investigate the system performance when power is supplied to resistive-inductive load. With three different cases, the evaluation of the system is done. Firstly, the robustness of control strategy under variable DC-Link is done in terms of the THD （total harmonic distortion）. Secondly, with one prediction step, the system performance is tested using different sampling time, and lastly, the dynamic response of the system with step change in the amplitude of the reference is investigated. The simulations and result analyses are carried out using Matlab/Simulink to test the effectiveness and robustness of FS-MPC for two-level VSI with AC filter for resistive-inductive load supplied by a renewable energy system.     

Voluntary Carbon Market in Turkey

Nowadays, global warming is a major environmental concern. Climate change is dominating the environmental agendas, especially in developed countries at first, but by now, around the world. Several initiatives have been undertaken to reduce the effect of increasing atmospheric GHGs （greenhouse gasses） concentrations. Emerging carbon emissions trade under the Kyoto Protocol serves to market the carbon quotas among the countries, thus, it helps to increase their level of GNP （gross national product）. Emissions trade is being performed in the voluntary and compliant markets. Increasing interest in emission trade emerged carbon and energy exchanges markets in the world. Turkey is located in the voluntary markets, and organizations buying carbon offset credits in order to achieve their voluntary emission reduction goals. GS （gold standard） and VCS （verified carbon standard） are mainly being used to finance renewable energy projects in Turkey. In the GS, there are 209 projects which are currently in the approval process or in the application, such as wind energy, hydroelectric power plant and biogas energy production. In addition to these, in the VCS, there are 61 projects which are mainly energy industries, in the approval process or in the application. Most environmental issues require long-term plans which include international cooperation, especially climate change. The Kyoto Protocol marks the beginning of a new era to combat global climate change. Voluntary markets are very popular and forty percent of the total global GS projects and around nine percent of VCS projects are implemented in Turkey. These projects are initial steps for future implementations of compliant markets in Turkey.