LCOE is an undiscounted metric that distorts comparative analyses of energy costs

Levelized Cost of Energy (LCOE) is a popular metric used to calculate the expected lifetime costs of a generation project on a unit-cost basis. Contrary to common understanding, however, LCOE is not a discounted metric but rather an undiscounted metric that distorts comparisons, with the distortion increasing with discount rate and with the length of analysis period. A different metric, the present value of the cost of energy (PVCOE), is proposed.     

计及可靠性评估的中压配电网规划方案比选

从可靠性参数搜集及计算方法和备选规划方案比选两方面切入,进一步丰富DL/T 1503—2016中压配电网可靠性评估导则在规划中的应用,提出了基于可靠性评估的中压配电网的方案形成与比选方法,内容包括相关参数的搜集、可靠性计算方法和方案比选。综合考虑可靠性与经济性,基于"有无对比法"给出配电网投资的增量净效益计算模型,并分析不同网架供电能力与负荷需求关系下净效益简化模型与全寿命周期成本最小化比选方案的异同。基于全寿命周期净现值、净现值率等动态指标进行投资成本效益分析,可用于多个方案的比选。案例表明,本文方法有效。     

Investments in combined cycle natural gas-fired systems: A real options analysis

Energy projects with extended life cycle and initial investments can be non-profitable under discount cash flow methods. Therefore, real options analysis has become relevant as a pricing technique for these types of projects, with private risks and high investment levels. Following this question, this study analyses different real options approaches to select the most adequate for making investment decisions in the energy sector. Combined cycle natural gas-fired plants constitute relevant generation assets that building decisions can mostly be studied by real options tools. Because traditional pricing approaches (e.g. net present value, internal rate of return, benefit-cost ratio) fail to take into account the worth of flexibility, conditions for creating significantly large options-based value can be found. Being unable to capture the value associated with the decision maker’s ability to dynamically react to changing market conditions, these assets constitute a fine example of asset flexibility which contributes to increasing its intrinsic value.Employing a real options approach that fails to capture the uncertainty of all the periods and proposes a process that determines directly the uncertainty associated with the first period, the paper study concludes that its use can be considered fair. However, it shows that long periods of operation and poor adhesion to the Geometric Brownian Motion by the project returns might call into question its use in the energy market. The values for option pricing have remained inside acceptable ranges but some shortfalls could be found. First, the study employs Monte-Carlo simulations which can be viewed as forward-looking processes and option pricing problems need backward recursive solutions. Second, the study demonstrates that its simplicity reaches results as accurate as those derived from approaches with additional complexity and computational requirements.     

塔式太阳能热发电全寿命周期成本电价分析

塔式太阳能热发电是全球新能源近年发展的新亮点之一,成本电价高是制约其发展的主要原因。文中给出了塔式太阳能热发电站成本电价计算的全寿命周期模型,并结合建造成本、运营维护成本及发电量的预测,对影响成本电价的因素逐一分析,测算了中国塔式太阳能热发电站的预期成本电价。重点从材料、加工和安装运输3个维度对定日镜成本的变化趋势进行了分析。计算结果表明,成本电价随产能规模、单机装机容量及技术工艺因素的发展而下降,其中产能规模作用最为明显。     

Economic analysis of solar energy development in North Africa

The economic analysis of solar energy development is the basis of promoting the solar energy planning in north Africa and realizing the clean energy power transmission among continents. In this paper, the cost development trend of photovoltaic(PV) power and concentrating solar power(CSP) generation is analyzed, and the levelized cost of energy(LCOE) of solar power generation is forecasted. Then, taking the development of Tunisian solar energy as an example in the context of transcontinental transmission, PV power with energy storage and PV-CSP power generation are given as two kinds of development plan respectively. The installed capacity configurations of the two schemes are given with production simulation method, and comprehensive LCOE are calculated. The studies show that based on the LCOE forecast value, the LCOE of PV-CSP combined power generation will decrease when the annual utilization hours of transmission channel is increased. It can be chosen as one of important mode of the North Africa solar energy development.     

An evaluation of electricity system technology competitiveness metrics: The case for profitability

In this work we develop standardized functional forms for electricity technology competitiveness metrics and show how the mathematical relationship between value and cost can affect the robustness of the metric. We make the case to replace established metrics with economic profitability metrics – including a new profitability-based adjustment to LCOE. These profitability metrics are shown to be more robust for evaluating technology competitiveness by keeping comparisons on an equivalent monetary basis.     

计及置信容量的光热电站储热容量优化配置

为探索光热电站的容量价值,文中基于光热电站的容量置信度和度电成本,提出一种光热电站集热面积和储热容量优化方法。文中建立光热电站发电效率模型和经济性模型,基于序贯蒙特卡洛方法计算发电系统可靠性,使用粒子群算法计算光热电站置信容量,研究太阳倍数和储热时长分别对光热电站容量置信度和度电成本的影响;并以容量置信度和度电成本作为优化目标,使用加权理想点法建立目标优化函数、熵权法确定指标权重值,对太阳倍数和储热时长进行优化。以西北某地区光热规划为例,使用该地区实际太阳辐照资源数据建立模型,发现随着太阳倍数和储热时长的增加,容量置信度单调递增,而度电成本呈先降后升的趋势,可优化得到约束条件下最佳太阳倍数和储热时长。     

基于平准化电力成本分析的微电网电源优化配置

平准化电力成本是用于评价各种发电技术的主要经济性指标。将平准化电力成本引入微电网的电源优化配置问题中,提出了适用于独立微电网电源的平准化电力成本评价方法,建立了以平准化电力成本最小为目标的独立微电网电源优化配置模型。采用蒙特卡罗方法对微电源出力和系统可靠性进行仿真;采用遗传算法对模型进行求解;算例结果验证了模型的有效性,并评估了初始投资费用、燃料费用以及可靠性对优化配置结果的影响。所建立的模型能够精确评估微电网各电源联合发电的单位成本,合理配置各电源的装机容量,为微电网电源规划提供了一种新方法。     

电源投资规模选择权的实物期权方法

规模经济是企业降低成本的一种有效方法,在目前的电源项目投资决策中,忽略了电源建设规模灵活性选择权的价值。在考虑燃料成本变化的情况下,以建设不同规模、不同燃料的机组为研究对象,以未来成本流现值最小化为目标函数,考虑机组规模大小选择权的价值,建立了电源投资决策的数学模型,导出了基于实物期权的决策准则,改进了净现值决策准则。     

面向多类型工业用户的分散式共享储能配置及投资效益分析

针对传统一体化式共享储能存在的灵活性较差且无法兼顾多类型用户的差异性用电需求等问题,提出一种分散式共享储能系统优化配置与调度方法;针对用户通过储能补贴政策漏洞骗取补贴收益的问题,在已出台政府补贴政策的基础上,提出一种改进分时补贴策略.首先,以工业园区为应用背景,深入分析了分散式共享储能系统与多个工业用户的能量交互机理;然后,以多用户整体净收益最大化为目标构建了基于合作博弈的月前、日前两阶段优化调度模型,并采用Shapley值法对合作收益进行分配;接着,设计了以储能全寿命周期净收益、动态投资回收期、投资回报率为指标的储能投资评估方法;最后,通过对比一体化式共享储能和分散式共享储能的配置成本、运行经济性,对所提方法的有效性进行了验证.算例结果表明:所提分散式共享储能配置方法在降低工业用户初期投资成本、用电成本方面具有一定的先进性,所提改进分时补贴策略在防止用户投机骗补方面具有一定的有效性,对推动用户侧储能多元化发展具有理论指导意义.     

实物期权方法及其在电力系统中的应用

很多国家和地区正在对电力工业进行放松管制和市场化改革,这将给电力系统的投资决策带来更多不确定性因素.传统的投资方案评估大多采用净现值(NPV)法,难以计及项目的管理灵活性;实物期权方法(ROA)较好地解决了这一问题,并已开始应用于研究电力投资决策方面的问题.首先简要介绍了实物期权的一些概念,然后对现有的实物期权定价的几种主要方法进行了总结,最后对ROA在电力系统中应用的研究现状做了简要综述,指出几个有待进一步研究的问题.     

Valuing distributed energy resources: Combined heat and power and the modern grid

In this paper we examine how decision makers can more precisely assess the costs of disruptive weather events and the value of resilient distributed energy systems such as combined heat and power (CHP). CHP makes up a small percentage of the energy infrastructure in the United States despite its substantial efficiency and resilience benefits. In part this is because the resilience value of CHP is not fully accounted for in energy infrastructure project cost screenings. To capture this benefit in investment decisions, we propose a framework for a metric called the Distributed Energy Resource Resiliency Value (DERRV) and discuss how such a metric might be applied to CHP.     

Optimal transmission expansion planning for electric power systems

This paper presents a new method for transmission expansion planning in which the utility loss revenue and the customer outage cost resulting from service outages are incorporated. A new algorithm based on the total probability formula is developed for evaluating the expected value of demand not served (EDNS) and the expected value of energy not served (EENS). These reliability indices are employed to determine the utility loss revenue curve. The system expansion cost curve is obtained by using a maximum reliability design algorithm. The optimal reliability level of a transmission expansion plan is determined by minimizing the sum of the investment cost, the utility loss revenue, and the customer outage cost. An example is presented for illustration of the proposed method.     

热电厂配置调峰电锅炉最佳容量确定方法

热电联产机组配置电锅炉进行热电解耦以促进风电等新能源的并网。为了确定热电联产机组参与电网调峰时电锅炉的最佳配置容量,引入特征日的概念,对电锅炉运行时的约束进行说明,分别以机组调峰增量和经济净现值为目标函数,建立电锅炉最佳容量的计算模型。结果表明,对于330 MW机组,当不考虑投资成本时,电锅炉的供热功率达到52 MW时,机组可以获得最大的调峰增量,此时,电锅炉的电加热功率为178.28 MW;若考虑投资成本,当电锅炉的供热功率达到49 MW时,即电锅炉的电加热功率为168 MW时,可以得到最大的经济净现值。     

基于层次分析法的储能配置综合评估技术

针对电池储能技术经济性逐渐提高、储能需求日益增长、部分电池储能技术应用效益性逐步凸显的现状,研究参与用户侧电能管理和需求响应的储能配置综合评估技术。基于层次分析法,提出了技术经济指标下不同储能规模间的标度计算方法,建立了综合评估指标的数学模型。考虑储能容量衰减,分别以投资成本、寿命、净现值、投资回收期、投资回报率等指标为上层目标函数;考虑削峰填谷、需求响应,以储能系统净年收益为下层目标函数,优化储能系统充放电曲线,提出了基于层次分析法的多目标优化模型求解方法。通过实例仿真验证了所提模型和方法的有效性和可行性,结果表明:综合评估指标可针对储能投资者的关注点,整体评估储能项目的可行性,得出综合评估指标最高时对应的储能规模。     

基于区间线性规划和可逼近理想解排序法的园区型综合能源系统投资决策

综合能源服务作为电网企业增值服务重点开发的领域,研究其在计及不确定性因素情况下的投资决策方法,能够有效提升电网的投资效益。从综合能源投资者角度出发,提出一种基于区间线性规划和可逼近理想解排序法 (technique for order preference by similarity to ideal solution,TOPSIS)的园区型综合能源系统投资决策方法。首先,采用区间数的方式对负荷和能源价格的不确定性进行描述,构建基于区间数的综合能源系统不确定性规划模型,求解得到年综合成本和年碳排放成本;然后,综合考虑园区的经济性指标和环保性指标,选取TOPSIS法对多个投资规划方案进行排序,统筹筛选出综合经济性和环保性的最优方案。案例分析结果表明所提方法可有效辅助综合能源公司做出合理投资决策。     

计及参与成本贡献的用户侧云储能服务及其纳什议价模型

为了解决以共享经济概念为基础的云储能服务中用户与运营商之间的成本贡献及收益分配问题,提出了计及参与成本贡献的用户侧云储能服务及其纳什议价模型,对运营商独立投资的集中式云储能服务进行定价。在所述服务框架中,运营商优先对充放电需求互补的用户交换电能,再通过充放电或购售电来满足总体的净充放电需求;然后,采用Shapley值法为用户分配储能损耗贡献度,并综合考虑用户的新能源余量能量互济率及虚拟储能利用率,对分配结果改进,以进一步刻画用户服务费的差异性;最后,求解计及用户成本贡献的纳什议价模型,计算各用户的服务费。算例结果表明：所提方法减小了储能充放电损耗及总体用能成本,并提升了新能源消纳率;且改进Shapley值法的分配结果促进了用户将新能源余量上网及按需租赁虚拟储能。同时,纳什议价模型在保证用户服务费差异合理的前提下,兼顾了用户群体和运营商之间的利益诉求,促进了双方合作。     

An economic analysis model for the energy storage system applied to a distribution substation

Recent developments and advances in energy storage technologies are making the application of energy storage technologies a viable solution to power applications. The energy storage system can store energy previously, and then release it in the proper time. Due to their flexibility, it is suitable to apply this technology to deregulated power markets. Therefore, this paper will build the economic analysis model for the energy storage system to apply to a distribution substation in a deregulated power market. The costs including installing energy storage system and operation and maintenance expense, and the revenues containing energy price arbitrage, reducing transmission access cost, and deferring facility investment are considered in this model. All these factors are evaluated by present worth value. Due to complexity of this problem, this paper proposes a method combining the genetic algorithm with linear program (GALP) to determine the optimal capacity and operations of the energy storage system.     

Estimation of lifespan and economy parameters of steam-turbine power units in thermal power plants using varying regimes

The use of potent power units in thermal and nuclear power plants in order to regulate the loads results in intense wear of power generating equipment and reduction in cost efficiency of their operation. We review the methodology of a quantitative assessment of the lifespan and wear of steam-turbine power units and estimate the effect of various operation regimes upon their efficiency. To assess the power units’ equipment wear, we suggest using the concept of a turbine’s equivalent lifespan. We give calculation formulae and an example of calculation of the lifespan of a steam-turbine power unit for supercritical parameters of steam for different options of its loading. The equivalent lifespan exceeds the turbine’s assigned lifespan only provided daily shutdown of the power unit during the night off-peak time. We obtained the engineering and economical indices of the power unit operation for different loading regulation options in daily and weekly diagrams. We proved the change in the prime cost of electric power depending on the operation regimes and annual daily number of unloading (non-use) of the power unit’s installed capacity. According to the calculation results, the prime cost of electric power for the assumed initial data varies from 11.3 cents/(kW h) in the basic regime of power unit operation (with an equivalent operation time of 166700 hours) to 15.5 cents/(kW h) in the regime with night and holiday shutdowns. The reduction of using the installed capacity of power unit at varying regimes from 3.5 to 11.9 hours per day can increase the prime cost of energy from 4.2 to 37.4%. Furthermore, repair and maintenance costs grow by 4.5% and by 3 times, respectively, in comparison with the basic regime. These results indicate the need to create special maneuverable equipment for working in the varying section of the electric load diagram.     

Optimal planning of rural medium voltage distribution networks

A model is suggested for selection of main initial parameters and timing of the reconstructions of rural distribution networks in long-term planning to meet the increasing load demands with minimum total present worth cost. The model incorporates capital and exploitation costs as well as the costs due to undelivered energy and load curtailments. The optimal investment policy is determined using a constrained dynamic programming technique which indicates the best choice among possible options while taking into account all relevant technical criteria and common-sense rules.