Identification of optimal strategies for sustainable energy management in Taiwan

In this study, an optimization model was developed for identifying optimal strategies in adjusting the existing fossil fuel‐based energy structure in Taiwan. In this model, minimization of the total system cost was adopted as the objective function, which was subject to a series of constraints related to energy demand, greenhouse gas (GHG) emission restriction, and energy balance. Feasibility of several potential energy structures was also evaluated through tradeoff analysis between energy system costs and GHG emission targets. Three scenarios were established under several GHG emission restriction targets and potential nuclear power expansion options. Under the three scenarios, optimal energy allocation patterns were generated. In terms of the total energy system cost, the scenario that restricted GHG emissions and nuclear power growth would result in the highest one, with an average annual increase of 4.2% over the planning horizon. Also, the results indicated that the energy supply structure would be directly influenced by energy cost and GHG emission reduction targets. Scenario 2 would lead to the greatest dependence on clean energy, which would take up 41.8% in 2025. In comparison, with no restriction on nuclear energy, it would replace several energy sources and contribute to 34.0% of the total energy consumption. Significant reduction in GHG emission could be identified under scenario 2 due to the replacement of conventional fossil fuels with clean energies. Under scenario 3, GHG emission would be significantly reduced due to the adoption of nuclear power. After 2015, energy structure in Taiwan would be slightly adjusted due to synthetic impacts of energy demand growth and GHG emission restriction. The results also indicated that further studies would be necessarily needed for evaluating impacts and feasibilities of clean energy and nuclear power utilization in Taiwan. Copyright © 2011 John Wiley & Sons, Ltd.     

Multi-objective optimization model for sustainable Indonesian electricity system: Analysis of economic,environment, and adequacy of energy sources

This paper presents a multi-objective optimization model for a long-term generation mix in Indonesia. The objective of this work is to assess the economic, environment, and adequacy of local energy sources. The model includes two competing objective functions to seek the lowest cost of generation and the lowest CO₂ emissions while considering technology diffusion. The scenarios include the use of fossil reserves with or without the constraints of the reserve to production ratio and exports. The results indicate that Indonesia should develop all renewable energy and requires imported coal and natural gas. If all fossil resources were upgraded to reserves, electricity demand in 2050 could be met by domestic energy sources. The maximum share of renewable energy that can be achieved in 2050 is 33% with and 80% without technology diffusion. The least cost optimization produces lower generation costs than the least CO₂ emissions, as well as the combined scenario. Total CO₂ emissions in 2050 are five to six times as large as current emissions. The least CO₂ emissions scenario can reduce almost half of the CO₂ emissions of the least cost scenario by 2050. The proposed multi-objective optimization model leads some optimal solutions for a more sustainable electricity system.     

Goal programming model for sustainable electricity production from biomass

In this paper, we present a goal programming model for block level energy planning in order to make a block self‐sufficient in electricity consumption, which includes the commercial energy consumption goal, the goal of generating electricity from biomass and food production goals with linear constraints on the available sources such as human power, animal power, tractor power, land area and on the requirement of the block such as cooking energy, lighting energy and energy for other operations, such as fodder for animal population. We try to achieve these goals through proper allocation of land for different crops. After reformulating the developed goal programming model into a linear programming format, we use the HYPER LINDO software package to solve it in a Pentium‐based IBM‐PC compatible computer system. The developed model is solved for a typical Indian block, namely Nilakkottai Block in Tamil Nadu, India. The model solution shows that the goal of generating electricity from biomass is achieved, the commercial energy consumption goal and pulses requirement goal are under‐achieved and the sugar requirement goal is over‐achieved. Furthermore, the cereal, vegetable and oilseed production goals are achieved. Copyright © 2000 John Wiley & Sons, Ltd.     

The role of nuclear energy in long-term climate scenarios: An analysis with the World-TIMES model

There is a revival in the nuclear debate observed in the literature. Several analyses have shown that nuclear technologies may represent very attractive options for greenhouse gas (GHG) emission reductions, especially in countries with high growth projections for energy demand. Our objective is to analyze the role of nuclear energy in long-term climate scenarios using the World-TIMES (The Integrated MARKAL-EFOM System) bottom-up model. World-TIMES is a global model that optimizes the energy system of 15 regions over a 100-year horizon (2000–2100).     

能源供需优化模型在北京市能源系统的应用

依据北京市“十一五”时期发展规划，立足于北京市目前能源消费现状，创建了能源供需优化模型，旨在满足能源需求、环境允许的前提下使得系统能源费用最小化。采用了区间线性优化方法，对已知上下界但其分布未知的参数用区间数表示，最后得出规划期的三个周期内八种能源的产出调入量以及各个周期的总费用，并对目前北京市能源消费中存在的问题提出了几点建议。     

一种基于经济、社会、环境可持续发展的城市群低碳优化模型

结合"十二五"某城市群区域规划,选取规划中提出的碳强度、能耗强度两项指标为约束条件,构建了一种基于经济、社会、环境可持续发展的城市群低碳优化模型。优化结果表明:在满足碳强度、碳汇面积、能耗强度、GDP等条件下,城市群"十二五"末期碳排放总量为3.70×107t,较2010年区域碳强度下降了35.56%,能耗强度下降了40.49%,城市群"核心区"碳强度下降了36.77%,能耗强度下降了37.99%,不仅满足国家《"十二五"控制温室气体排放工作方案》中提出2015年的碳强度、能耗强度较2010年分别降低17.00%和16.00%的要求,而且满足该城市群区域规划中提出2015年的碳强度、能耗强度较2010年分别降低18.00%和20.00%的目标,该优化方案为城市群的低碳发展提供了一定的决策空间。     

Bases for a sustainable energy model. Case study: Basque autonomous community

The current Spanish energy model has become obsolete for social, economic and environmental reasons. This conditions the economic and social model of the country. To change the model, a transition period is required and the identification of energies available in the vicinity, citizen commitment, the mobilisation of technological and economic resources, a model of efficiency, generation and distribution. In this new model, compliance with environmental commitments, the generation of economic activity and the guarantee that the transition will not involve uncertainty in terms of availability and security of supply, must be unquestionable commitments. To this end, the possibilities of implementing a sustainable energy model, of proximity, that allows maintaining an industrial economic structure, has been studied in a region of the Basque Autonomous Community (Spain). This article presents the different phases of the study, the methodology used, conclusions and the bases for a sustainable model.     

Mathematical model for energy planning of rural India

This paper describes an integrated energy system planning approach for Wardha District in Maharashtra State, India, for the year AD 2000 and gives an optimal mix of new/conventional energy technologies using a computer-based mixed integer linear programming model. The district level planning is accomplished by successively applying in two stages a new statistical extrapolation technique for moving first from the village level energy scenarios based on surveys to the corresponding energy scenarios at the block level and then for moving next from the block level scenarios to the desired district level planning profile. The model is suitably scaled for obtaining the optimal results at the district level owing to limitations on the available memory on the PC-AT system in use. Energy options for seasonal crops have been considered explicitly in the model. Post-optimal analysis based on a linear programming model to study the effect of the variations in parameters on the optimal solution has been performed.     

A fuzzy programming approach to energy resource allocation

This paper presents a fuzzy multi‐objective linear programming approach to solve the energy allocation problem. For this, nine energy resources and six household end uses are considered. An optimal solution will be extracted, and an explicit interactive sensitivity analysis will be dealt with. As the results obtained depend on the fuzzy nature of the objective functions and on the conflicting nature of some of the objectives among themselves, the proposed method can be regarded as a decision support tool for the decision makers who can be guided by its results to arrive at an appropriate solution interactively. It will be shown that optimization using fuzzy logic can provide the decision‐makers with more flexibility that would assist them in the allocation of various resources to meet the various end‐uses by studying the effects of several factors such as price variations, membership function shapes and membership function reference values. Copyright © 1999 John Wiley & Sons, Ltd.     

Turkish aggregate electricity demand: An outlook to 2020

This paper investigates the relationship between Turkish aggregate electricity consumption, GDP and electricity prices in order to forecast future Turkish aggregate electricity demand. To achieve this, an aggregate electricity demand function for Turkey is estimated by applying the structural time series technique to annual data over the period 1960 to 2008. The results suggest that GDP, electricity prices and a UEDT (Underlying Energy Demand Trend) are all important drivers of Turkish electricity demand. The estimated income and price elasticities are found to be 0.17 and −0.11 respectively with the estimated UEDT found to be generally upward sloping (electricity using) but at a generally decreasing rate. Based on the estimated equation, and different forecast assumptions, it is predicted that Turkish aggregate electricity demand will be somewhere between 259 TWh and 368 TWh in 2020.     

Assessment of sustainable biomass resource for energy use in China

This paper assesses the sustainable biomass resource for energy in China. Assessment has been carried out for the following resources: (i) agricultural residues, (ii) forest residues, and (iii) municipal solid waste (MSW). The potential of each resource is estimated for the base years 2008, 2008, and 2007. The energy potentials of these resources in 2008, 2008, and 2007 are estimated to be 14.7, 3.9, and 0.2 EJ, respectively. The total potential including the energy of 6.4 EJ from the proposed low-input high-diversity (LIHD) grassland biomass on the untilled lands for the base years 1996 is equal to about 30.2% of China’s energy consumption in 2008. Furthermore it is projected that sustainable biomass use for energy will reduce net emissions of green house gases (GHG) of 3276.7 million tonnes, and help in emission-reduction target of China and the world.     

A model for investigation of optimal hydrogen pathway,and evaluation of environmental impacts of hydrogen supply system

In order to achieve a hydrogen economy, developing widespread hydrogen supply systems are vitally important. A large number of technological options exist and are still in development for hydrogen production, storage, distribution…, which cause various pathways for supplying hydrogen. Besides the technical factors, there are other effective parameters such as cost, operability, reliability, environmental impacts, safety and social implications that should be considered when assessing the different pathways as optimal and viable long-term alternatives. To aid this decision-making process, we have developed a generic optimization-based model for the long-range energy planning and design of future hydrogen supply systems. By applying Linear Dynamic Programming techniques, the model is capable of identifying optimal investment strategies and integrated supply system configurations from the many alternatives. Also, the environmental impacts of hydrogen supply system can be evaluated through scenario analysis. The features and capabilities of the model are illustrated through application to Iran as a case study.     

How to achieve optimal and sustainable use of the subsurface for Aquifer Thermal Energy Storage

A heat pump combined with Aquifer Thermal Energy Storage (ATES) has high potential in efficiently and sustainably providing thermal energy for space heating and cooling. This makes the subsurface, including its groundwater, of crucial importance for primary energy savings. The regulation of ATES systems is similar in many countries around the world. This paper seeks solutions for the institutional hindrances to the diffusion of ATES. The use of aquifers by individual ATES systems can be optimized to maximize their efficiency on the one hand, and to optimize the performance of the regional subsurface for energy storage on the other. The application of ATES in an aquifer has similar properties as other common resource pool problems. Only with detailed information and feedback about the actual subsurface status, a network of ATES systems can work towards an optimum for both the subsurface and buildings, instead of striving for a local optimum for individual buildings. Future governance of the subsurface may include the self-organization or self-governance. For that the ATES systems need a complementary framework; interpretation of interaction, feedback and adaptable and dynamic control interpretations are the key elements for the optimal and sustainable use of the subsurface.     

Optimal mix of technologies for rural India: Combined model for cooking,irrigation and lighting sectors

A combined linear programming model for three important end uses, namely cooking, irrigation pumping, and lighting, in rural areas of India, is described. The results of the solution of the combined model are presented. A brief comparison of these results with the results of the individual submodels is also discussed.     

Model‐based approach for planning renewable energy transition in a resource‐constrained electricity system—A case study from India

Globally, electricity systems are going through transitions. The contributions from renewable energy‐based power generation, both in installed capacity and electricity generation, are moving from marginal to the mainstream. India is not an exception; it is aggressively pursuing this transition by fixing steep targets for renewable capacity additions. While the cost of renewable energy sources is expected to fast reach grid parity, the policy interventions play a critical role in ramping up the efforts to support the proposed investments in renewable capacity and renewable electricity generation. In this respect, this research attempts to analyze the effectiveness of renewable energy policies such as Renewable Purchase Obligation (RPO) and Renewable Energy Certificate mechanisms in tapping the renewable energy potential in India. We propose a mixed‐integer linear programming model‐based approach to evaluate the effectiveness of the above interventions in the Indian context. The model is developed and validated as a low carbon electricity planning tool to optimally meet the dynamic electricity demand and RPO targets as well as to manage the unmet total electricity demand and RPO targets. The Karnataka state electricity system (a state in south India) is chosen as a case study. The results suggest that Karnataka Electricity System is moving toward a sustainable renewable energy future even without any support from nonsolar Renewable Energy Certificate policy. However, policy interventions are critical for optimally utilizing the solar generation capacity.     

A general source-sink model with inoperability constraints for robust energy sector planning

The concept of inoperability was originally introduced as a means of quantifying risk in systems comprised of interdependent subsystems, using a modified input–output framework. This paper describes a novel robust optimization model for energy planning with inoperability constraints. The formulation is based on the established source-sink framework, which has been used extensively for energy planning applications under various environmental footprint constraints. The proposed model determines the optimal allocation of various energy sources within a system to corresponding energy sinks or demands, while ensuring that inoperability limits of the latter are satisfied for multiple enumerated scenarios. The basic formulation results in a linear program (LP), while a mixed integer linear programming (MILP) extension is also described. In either case, a globally optimal solution can be easily determined if one exists. Illustrative case studies are then given to demonstrate this new method.     

Multi-objective optimal allocation strategy for the energy internet in Huangpu District,Guangzhou, China

To improve the overall efficiency of the energy system, the basic structure for the energy internet of coordination and optimization of “generation-grid-load-storage” of Huangpu District, Guangzhou, China is designed, while the arrangement for the output of centralized and distributed energy module and energy storage are proposed. Taking economic benefit maximization, environmental benefit maximization and energy efficiency maximization as sub-objectives, the mathematical model of multi-objective optimal allocation and operation strategy of the energy internet is established considering supply-demand balance constraints, equipment characteristic constraints, operation mode constraints, and energy conditions constraints. The calculation results show that without considering the outsourced electricity, the balanced strategy, the economic development strategy, the environmental protection strategy, and the energy efficiency strategy are obtained by calculation, which are all superior to the traditional energy supply strategy. Moreover, considering the outsourced electricity, the proportion of outsourced electricity to total electricity is 19.8%, which is the system optimization of the energy internet under certain power demand. Compared with other strategies without outsourced electricity, the outsourced electricity strategy can have a certain emission reduction effect, but at the same time reduce the economic benefit. Furthermore, the huge difference in demand for thermal and cooling load between industrial and commercial areas results in the installed capacity of gas distributed energy stations in industrial areas being nearly twice as large as that in commercial areas. The distributed photovoltaic power generation is allocated according to the proportion of the installed roof areas of photovoltaic power generation system in residential, industrial, and commercial areas.     

Renewable energy integration through optimal unit commitment and electricity storage in weak power networks

In this work, the impact of intermittent renewable energy sources on total production cost is evaluated, using annual data regarding the isolated power system of the island of Cyprus. Once electrical energy storage (EES) is identified as an approach enhancing flexibility and reliability, the selected EES facilities are modelled and evaluated via a life-cycle cost analysis, based on the most realistic characteristics and cost metrics found in the literature. The results derived from the uncertainty analysis performed, show that vanadium-redox flow battery provides the highest net present value (NPV). However, sodium-sulfur battery system offers the most secure investment in terms of uncertainty range and mean value, followed by lead-acid battery system. Lithium-ion battery system exhibits expensive capital cost which still governs its overall cost performance achieving a negative mean NPV far below zero.     

Shaping a sustainable energy future for India: Management challenges

Most of the studies on the Indian energy sector focus on the possible future scenarios of Indian energy system development without considering the management dimension to the problem—how to ensure a smooth transition to reach the desired future state. The purpose of this paper is to highlight some sector management concerns to a sustainable energy future in the country. The paper follows a deductive approach and reviews the present status and possible future energy outlooks from the existing literature. This is followed by a strategy outline to achieve long-term energy sustainability. Management challenges on the way to such a sustainable future are finally presented. The paper finds that the aspiration of becoming an economic powerhouse and the need to eradicate poverty will necessarily mean an increase in energy consumption unless a decoupling of energy and GDP growth is achieved. Consequently, the energy future of the country is eminently unsustainable. A strategy focussing on demand reduction, enhanced access, use of local resources and better management practices is proposed here. However, a sustainable path faces a number of challenges from the management and policy perspectives.     

An assessment of the use of fuel chemicals synthesized from captured carbon dioxide for renewable electricity storage

本文介绍了国际上利用可再生能源结合捕集CO₂制燃料的最新技术进展。以化学合成的反应热力学为基础,通过分析计算与流程模拟,得到捕集CO₂制燃料化学品储电的能耗与?流,初步评估了甲醇作为储存电能介质的能效,并与氢储能及甲烷储能进行了比较分析。比较结果表明,氢储能流程最短,效率最高,但是没有固碳的作用。对于实现储能与固碳,甲醇的氢原子经济性较好。甲烷产物热值与反应热都较高。甲醇储能效率损失主要由前端电解制氢环节造成。