A multiple objective linear programming model for power generation expansion planning

The planning of new units for electrical power generation is a problem which involves different and conflicting aspects. Besides cost, security issues and environmental concerns must be explicitly incorporated into the models. In this way mathematical models become more realistic, and they enhance the decision maker's comprehension of the complex and conflicting nature of the distinct aspects of the problem. A multiple objective linear programming model for power generation expansion planning is presented. The model considers three objective functions (net present cost of the expansion plans, reliability of the supply system, and environmental impacts) and three categories of constraints (load requirements, operational restrictions and budget). Three generating technologies are considered for power system expansion: oil, nuclear and coal.     

Determination of acceptable operating cost level of nuclear energy for Turkey's power system

Generally, it is very difficult to assess the true operating cost of an electrical power unit in the countries where there is little or no operational experience. Since Turkey has no experience on operating a nuclear unit, operating costs of a nuclear unit is uncertain for use in generation expansion planning (GEP). Furthermore, there is a disagreement of whether it is cheap or not. In this study, an acceptable level of operating cost of nuclear units is determined for Turkey's power system. It is aimed to find a numerical value for nuclear operating cost at which nuclear is able to compete with other energy sources. Seven types of units are chosen as candidate units to the power system. Mixed-integer programming (MIP) is used as a mathematical model of generation expansion planning. The model consists of the cost function that minimizes the construction and operating costs and the reliability constraints. Adaptive simulated annealing genetic algorithm (ASAGA) is used for optimization algorithm to determine the types, times, and number of candidate units which meet forecasted demand within a pre-specified reliability criterion over the planning horizon from 2006 to 2025. In the case studies, a high level of nuclear energy operating cost is taken and then the cost is gradually lowered. Optimizations are made for each level of nuclear operating costs within four different scenarios and the quantities of nuclear capacity selected by optimizations are recorded. It is determined that, nuclear energy is able to compete with other energy sources when the operating cost is less than 210$/kWh yr or 2.4cent/kWh.     

基于改进多目标蝙蝠算法的洛河流域水库优化调度

为了发挥水资源综合利用的最大效益,实现水库发电和供水效益双赢的优化调度需求,以水库发电量最大和水库下游用水区域总缺水量最小为目标建立了多目标优化调度模型。同时,提出改进多目标蝙蝠算法(IMOBA)用于求解多目标优化调度模型,该算法引入外部精英蝙蝠集EBS()来存储算法寻优过程中的非劣解,设计一种基于混沌原理的脉冲发射率生成机制来增强算法的搜索能力,并加入变异操作以提高算法的种群多样性。将改进多目标蝙蝠算法应用在洛河流域故县水库,得到丰、平、枯三种典型年下的故县水库调度方案集。结果表明,IMOBA算法合理有效且优于多目标蝙蝠算法(MOBA),能较好地反映洛河流域故县水库的发电和供水要求。同时验证了多目标优化调度模型的可行性,为流域水库多目标优化调度方案的制定提供了新途径。     

PV power conversion and short-term forecasting in a tropical,densely-built environment in Singapore

With the substantial growth of solar photovoltaic installations worldwide, forecasting irradiance becomes a critical step in providing a reliable integration of solar electricity into electric power grids. In Singapore, the number of PV installation has increased with a growth rate of 70% over the past 6 years. Within the next decade, solar power could represent up to 20% of the instant power generation. Challenges for PV grid integration in Singapore arise from the high variability in cloud movements and irradiance patterns due to the tropical climate. For a thorough analysis and modeling of the impact of an increasing share of variable PV power on the electric power system, it is indispensable (i) to have an accurate conversion model from irradiance to solar power generation, and (ii) to carry out irradiance forecasting on various time scales. In this work, we demonstrate how common assumptions and simplifications in PV power conversion methods negatively affect the output estimates of PV systems power in a tropical and densely-built environment such as in Singapore. In the second part, we propose and test a novel hybrid model for short-term irradiance forecasting for short-term intervals. The hybrid model outperforms the persistence forecast and other common statistical methods.     

Life cycle energy,emissions and cost inventory of power generation technologies in Singapore

Singapore is one of the most industrialised and urbanised economies in South-East Asia. Power supply is an important sub-system in its economy and heavily reliant on imported oil and natural gas. Due to its geographical area, clean/renewable energy sources for power generation are limited. At the same time, in its deregulated electricity market, the adoption of clean/renewable based power generation technology may be hindered by a market pricing mechanism that does not reflect externality costs. For a sustainable power supply, there is a need to change the conventional appraisal techniques. Life cycle assessment (LCA) and life cycle cost analysis (LCCA) are good tools to quantify environmental impacts and economic implications. LCA and LCCA are performed for centralised and distributed power generation technologies in Singapore, namely, oil and Orimulsion-fired steam turbines, natural gas-fired combined cycle plant, solar PV and fuel cell systems. A life cycle energy, emission and cost inventory is established. The results are discussed from the perspectives of fuel security, environmental protection and cost effectiveness of future power generation strategies for Singapore.     

Non-nuclear,low-carbon,or both? The case of Taiwan

The Fukushima nuclear accident in Japan has renewed debates on the safety of nuclear power, possibly hurting the role of nuclear power in efforts to limit CO₂ emissions. I develop a dynamic economy-wide model of Taiwan with a detailed set of technology options in the power sector to examine the implications of adopting different carbon and nuclear power policies on CO₂ emissions and the economy. Without a carbon mitigation policy, limiting nuclear power has a small economic cost for Taiwan, but CO₂ emissions may increase by around 4.5% by 2050 when nuclear is replaced by fossil-based generation. With a low-carbon target of a 50% reduction from year 2000 levels by 2050, the costs of cutting CO₂ emissions are greatly reduced if both carbon sequestration and nuclear expansion were viable. This study finds that converting Taiwan's industrial structure into a less energy-intensive one is crucial to carry out the non-nuclear and low-carbon environment.     

基于三阶段逐步优化算法的三峡水库水沙联合优化调度研究

针对水沙联合优化调度多目标、高维、难以求解以及泥沙淤积计算具有后效性的问题,以泥沙淤积量为基本目标、发电量为约束目标,利用约束法将多目标水沙联合优化调度模型转化为单目标模型,并采用三阶段逐步优化算法进行求解。以三峡水库水沙联合优化调度为例,获得了满意的水库发电与泥沙淤积的非劣解集及水库非劣运用过程,验证了所建立模型及提出的求解方法的合理性和有效性。     

基于风-光-蓄-火联合发电系统的多目标优化调度

针对风电、光伏出力的随机性、间歇性和波动性而导致其在大规模接入电网时对电网发电计划制定和调度产生的影响,提出了含风-光-蓄-火联合发电系统的多目标优化调度模型。利用抽水蓄能的抽蓄特性,将风电和光伏出力进行时空平移,使风-光-蓄联合出力转变为稳定可调度电源,具备削峰填谷的功能,与火电机组共同参与系统优化调度。以风-光-蓄联合出力最大、广义负荷波动最小和火电机组运行成本最小作为目标函数,建立多目标优化调度模型,通过多目标处理策略,使目标函数简化为2个,以降低问题维数;在求解阶段,利用分层求解思想,将模型划分为两层,分别采用混合整数规划方法和机组组合优化方法进行求解。10机测试系统仿真结果表明：所建模型可以提高风能和太阳能的利用率,缓解火电机组的调峰压力,大幅降低风电反调峰特性对电网的影响,从而保证电力系统安全、稳定、经济运行。     

Nuclear energy into the twenty-first century

The historical development of the civil nuclear power generation industry is examined in the light of the need to meet conflicting energy-supply and environmental pressures over recent decades. It is suggested that fission (thermal and fast) reactors will dominate the market up to the period 2010–2030, with fusion being relegated to the latter part of the twenty-first century. A number of issues affecting the use of nuclear electricity generation in Western Europe are considered, including its cost, industrial strategy needs, and the public acceptability of nuclear power. The contribution of nuclear power stations to achieving CO₂ targets aimed at relieving global warming is discussed in the context of alternative strategies for sustainable development, including renewable energy sources and energy-efficiency measures. Trends in the generation of nuclear electricity from fission reactors are finally considered in terms of the main geopolitical groupings that make up the world in the mid-1990s. Several recent, but somewhat conflicting, forecasts of the role of nuclear power in the fuel mix to about 2020 are reviewed. It is argued that the only major expansion in generating capacity will take place on the Asia-Pacific Rim and not in the developing countries generally. Nevertheless, the global nuclear industry overall will continue to be dominated by a small number of large nuclear electricity generating countries; principally the USA, France and Japan.     

计及(火用)分析的综合能源系统多目标优化调度

建立综合能源系统优化调度模型并进行高效求解有利于可再生能源的开发利用,发掘综合能源系统降本增效的潜力。针对含光伏发电的综合能源系统,以系统■效率倒数最小和总运行成本最小为目标,结合电-热-冷综合需求响应模型和运行约束,构建综合能源系统多目标运行模型。针对模型中存在的非凸非线性项进行等价线性转化处理,将问题由多目标混合整数线性分式规划等价转换为多目标混合整数线性规划,进一步采用ε约束法将其转换为一系列单目标混合整数线性规划问题进行高效求解获得帕累托Pareto前沿,并采用TOPSIS法进行决策。算例仿真表明,所建立的含光伏发电的综合能源系统能提升系统运行灵活性,相比于单目标运行,计及■分析的综合能源系统多目标优化调度能够实现系统运行成本和效率的折衷。     

Effect of Climate Change on wind speed and its impact on optimal power system expansion planning: The case of Chile

This work assesses the changes in power capacity expansion decisions regarding power generation and transmission that occur when the effects of Climate Change on wind speed are captured in the decision model. Considering an 85-year period (2016–2101), we use a Mixed-Integer Linear Program (MILP) model to analyze the optimal power capacity expansion in diverse types of power generation technologies, throughout the years and geographical locations. The optimization model minimizes the total (investment and operational) costs of the power system subject to several technical and economic constraints. We implement our model using the main Chilean power system. We compare two scenarios: one assuming that Climate Change affects wind speeds and hence wind farm capacity factors and the other assuming it does not. Our results reveal that, when taking into account the impact of Climate Change on wind speed, the optimal power generation and transmission expansion plan is different than when ignoring this effect. The variation of wind speed affects not only wind power capacity installed, but also other-technology power capacity installed. In particular, power capacity installed in wind and solar generation plants is higher (measured in MW installed) than the power capacity installed when we ignore the effects of Climate Change; and power capacity installed in diesel and natural gas technologies are lower. We perform sensitivity analyses, changing power capacity expansion limits and the discount rate, to check for the robustness of our results.     

Multi-objective optimization for capacity expansion of regional power-generation systems: Case study of far west Texas

High expansion of power demand is expected in the Upper Rio Grande region of far west Texas as a result of both electrical demand growth and decommissioning of installed capacity. On the supply side, a notable deployment of renewable power technologies can be projected owing to the recent legislation of a new energy policy in Texas, which attempts to reach 10,000 installed MW_e of renewable capacity for 2025. Power generation fueled by natural gas might consistently expand due to the encouraged use of this fuel. In this context, the array of participating technologies can be optimized within a sustainability framework, which translates into a multi-objective optimization problem. In this paper, the problem is formulated and solved to determine supply shares for some chosen technologies based on both renewable power conversion and natural gas use. The exergetic and economic costs are established as primary competing factors. The deployment of renewable power technologies hypothetically follows the Gompertz growth model, which is constrained by exergetic self sustenance. The solution is given as a Pareto tradeoff front for arrays of optimal technologies and capacities. Additionally, the sustainability of these arrays is analyzed through indicators, and the current goal for renewable power technologies is discussed.     

基于安全低碳的发电权交易优化

为提高发电权交易系统的环保性和安全性,提出包含碳排放量和负荷裕度的发电权交易双目标优化模型,采用NBI法对模型进行求解,绘制Pareto曲线;计算碳排放量与负荷裕度的置换度指标,直观地反映两者之间的置换关系,为决策者提供判断依据,并利用IEEE30、IEEE118系统验证了模型的有效性及正确性。结果表明,该模型可为决策者确定系统的交易方案及机组的发电计划提供依据。     

考虑户用光伏发电的家庭能量管理方法研究

当户用光伏发电接入家庭后,会导致家庭功率的波动以及电能分配问题的产生。针对家庭功率波动问题的同时,又兼顾经济效益,提出了基于PowerBox的家庭能量管理模型。在家庭能量模型中,结合粒子群算法,建立了考虑户用光伏发电的家庭能量管理方法。算例分析表明,所提方法具有降低家庭功率波动、节省电力花费的优点,能有效解决户用光伏在家庭能量管理中的多目标规划问题。     

Multi-stage power source and grid coordination planning method considering grid uniformity

Given the increasing uncertainties in power supply and load, this paper proposes the concept of power source and grid coordination uniformity planning. In this approach, the standard deviation of the transmission line load rate is considered as the uniformity evaluation index for power source and grid planning. A multi-stage and multi-objective optimization model of the power source and grid expansion planning is established to minimize the comprehensive cost of the entire planning cycle. In this study, the improved particle swarm optimization algorithm and genetic algorithm are combined to solve the model, thus improving the efficiency and accuracy of the solution. The analysis of a simple IEEE Garver’s 6-node system shows that the model and solution method are effective and feasible. Moreover, they are suitable for the coordinated planning of the power source and grid under a diversified nature of power supply and load.     

Non-dominated sorting culture differential evolution algorithm for multi-objective optimal operation of Wind- Solar-Hydro complementary power generation system

Due to the intermittency and instability of Wind-Solar energy and easy compensation of hydropower, this study proposes a Wind-Solar-Hydro power optimal scheduling model. This model is aimed at maximizing the total system power generation and the minimum ten-day joint output. To effectively optimize the multi-objective model, a new algorithm named non-dominated sorting culture differential evolution algorithm (NSCDE) is proposed. The feasibility of NSCDE was verified through several well-known benchmark problems. It was then applied to the Jinping Wind-Solar-Hydro complementary power generation system. The results demonstrate that NSCDE can provide decision makers a series of optimized scheduling schemes.     

Expansion of isolated electrical systems in the Amazon: An approach using fuzzy multi-objective mathematical programming

This paper examines some problems encountered in the expansion of isolated electrical systems (IES) in the Amazon region, more precisely, the thermoelectric systems used in that region. Supposing a certain degree of uncertainty in energy consumption, we evaluate the expansion of thermoelectric power from firewood and diesel fuel, together with variations for costs, CO₂ emissions, and number of direct jobs (NDJ) generated with the use of these technologies. The analysis is accomplished by using fuzzy multi-objective mathematical programming, and interpreting each objective function both by itself and in combination with the others, through a fuzzy multi-objective parametrization. The scenarios are defined by the energy consumption percentage increase, limited to be below some admissible maximum value, while still considering variations in the installed power. The costs, CO₂ emission, and the NDJ generated are analyzed and compared with the largest values obtained with the model of crisp mathematical programming, used for the original configuration. Finally, in Section 4, we present the results and respective analyses for the finished simulation.     

高风电渗透率下考虑需求侧管理策略的智能微电网调度方法

提出了一种高风电渗透率下考虑需求侧管理策略的智能微电网调度方法.首先,考虑经济、环境成本指标、清洁能源就地消纳量以及可中断负荷和可转移负荷策略,建立了多目标优化调度模型.然后,引入ε约束法生成Pareto前沿解集,利用归一化方法求出最优折衷解.最后,基于24节点配电系统对所提方法进行分析验证.算例结果表明:建立的多目标...     

The nuclear option for US electrical generating capacity additionsutilizing boiling water reactor technology

The technology status of the advanced boiling water reactor (ABWR) and the simplified boiling water reactors (SBWR) is presented along with an analysis of the economic potential of advanced nuclear power generation systems based on BWR technology to meet the projected domestic electrical generating capacity need through 2005. The forecasted capacity needs are determined for each domestic North American Electric Reliability Council (NERC) region. Extensive data sets detailing each NERC region's specific generation and load characteristics, and capital and fuel cost parameters are utilized in the economic analysis, by means of an expansion planning model, of the optimal generation additions required to meet this need. In addition to a reference case, several sensitivity studies are performed with regard to capital costs and fuel price escalation     

Using next generation nuclear power reactors for development of a techno‐economic model for hydrogen production

Nuclear and hydrogen are considered to be the most promising alternatives energy sources in terms of meeting future demand and providing a CO?‐free environment, and interest in the development of more cost‐effective hydrogen production plants is increasing—and nuclear‐powered hydrogen generation plants may be a viable alternative. This paper is a report on investigating the application of new generation nuclear power plants to hydrogen production and development of an associated techno‐economic model. In this paper, theoretical and computational assessments of generations II, III+, and IV nuclear power plants for hydrogen generation scenarios have been reported. Technical analyses were conducted on each reactor type—in terms of the design standard, fuel specification, overnight capital cost, and hydrogen generation. In addition, a theoretical model was developed for calculating various hydrogen generation parameters, and it was then extended to include an economic assessment of nuclear power plant‐based hydrogen generation. The Hydrogen Economic Evaluation Program originally developed by the International Atomic Energy Agency was used for calculating various parameters, including hydrogen production and storage costs, as well as equity, operation and maintenance (O&M), and capital costs. The results from each nuclear reactor type were compared against reactor parameters, and the ideal candidate reactor was identified. The simulation results also verified theoretically proven results. The main objective of the research was to conduct a prequalification assessment for a cogeneration plant, by developing a model that could be used for technical and economic analysis of nuclear hydrogen plant options. It was assessed that high‐temperature gas‐cooled reactors (HTGR‐PM and PBR200) represented the most economical and viable plant options for hydrogen production. This research has helped identify the way forward for the development of a commercially viable, nuclear power‐driven, hydrogen generation plant.