光伏电站设计中组件串联数的计算优化

为提高光伏电站的发电效率,进一步降低光伏电站的投资成本,提高整体经济性,针对目前光伏电站设计中组件串联数计算存在的问题和影响因素进行了探讨和分析,提出了优化后的计算方法;并结合实际设计算例,以系统效率和投资成本为目标进行了对比计算,优化后的计算方法可提升发电效率约0.25%。     

基于太阳电池Ⅰ-Ⅴ特性的光伏组件最大串联数的计算方法研究

为了进一步降低光伏发电系统的成本,提高光伏电站的经济性,针对目前光伏电站设计中采用的光伏组件串联数的计算方式和计算时存在的问题进行了阐述。基于太阳电池Ⅰ-Ⅴ特性方程建立了数学模型,并结合相关环境影响因素进行了光伏组件开路电压的修正;给出了光伏组件串联数最大值的优化算法,并结合实际算例,对采用优化算法的光伏发电系统的系统损耗和光伏电站投资成本进行了经济测算。与常规算法相比,优化算法可降低光伏电站的投资成本,为光伏电站的设计优化提供了一定的参考。     

基于遗传算法优化粗糙决策模型的光伏电站发电量的影响因素研究

通常光伏电站设计时要考虑2个主要目标,一个是使光伏电站的发电量最大,另一个是使光伏电站的度电成本最低。影响光伏电站发电量的因素众多,不同因素之间的相互影响及其交互影响极其复杂。在粗糙决策模型的基础上,引入遗传算法来寻找光伏电站发电量的主要影响因素。以光伏电站发电量作为决策属性,选取8个参数作为条件属性,建立了光伏电站发电量的诊断模型,通过计算分析,得到了影响光伏电站发电量的决策规则。结果表明:光伏组件串联数、热交换系数及交流线损是影响光伏电站发电量的决定性因素;对热交换系数较大的大型地面光伏电站而言,通过控制交流线损和光伏组件串联数可以更有效地提高光伏电站的发电量。     

基于组件输出功率估算的光伏电站经济效益研究

基于辐照度、温度等环境因素对光伏组件输出功率的影响程度,建立了光伏组件输出功率估算模型,对光伏电站的总装机成本、运营成本及收益进行了分析,给出了光伏电站项目的现金流,并选择内部收益率指标和净现值法,分析了光伏电站的经济效益,推导出期望内部收益率下的光伏电站成本、规模与发电量之间的匹配模型,提出了经济发电量和环境约束发电量的概念。通过算例对比分析两种发电量的差异,验证了模型的有效性和实用性,为光伏电站的选址和装机容量的选择提供了决策依据。     

基于优化LCOE的光伏平价上网可行性分析

平准化度电成本(LCOE)是国际上通用评价发电技术的主要经济性指标。在原有LCOE评估模型基础上,增加了考虑折旧抵税后的税收成本和损耗带来的额外成本,进一步优化成本模型,并考虑清洁发展机制(CDM)的收入因素,提出更准确、更完整的优化LCOE模型,并结合其他投资指标提出适应我国现状的光伏发电效益模型。以南京某3 MW分布式光伏电站项目为例进行敏感性分析,进一步探讨未来光伏平价上网的可行性,提出提高光伏系统单位造价和提高发电量是实现平价上网的主要途径。     

中国太阳能发电即将普及应用

国内首座普及型光伏电站将在江苏如东洋口港开建,该项目建设成本和发电成本只有多晶硅电池的40％左右。目前,在国外建设1MW光伏电站需要投资800万美元,国内运用晶体硅电池建设的1MW光伏电站示范项目投资额达6500万元人民币,而这座1MW并网电站成本仅为2800万元。此举标志着我国太阳能光伏发电进入实质性普及新阶段。     

基于HFLTS的漂浮式水上光伏电站投资风险评价

水上光伏是未来我国南方发展光伏产业的最优选择.但当前对水上光伏电站的研究较少,且风险评价是项目可行性研究的重要组成部分.为推进水上光伏电站的健康发展,通过对影响漂浮式水上光伏电站项目的投资风险因素进行识别,归纳梳理后建立了一套包含技术风险、经济风险、环境风险和社会风险的指标体系.考虑到评价语言的不确定性以及决策环境的模糊性,本文采用犹豫模糊语言术语集(HFLTS)进行信息收集,并采用最优最劣法(BWM)确定指标权重,最后通过模糊综合评价得出我国漂浮式水上光伏电站整体投资风险处于较低水平.     

大型地面光伏电站发电成本分析

近年来,中国的光伏产业发展迅速,发电成本逐渐降低.介绍了影响光伏发电成本的因素并分析了其对光伏发电成本的影响,同时以实例介绍了现阶段典型光伏电站发电成本及投资效益分析,为投资者进行光伏电站投资提供一定的理论技术支持.     

并网光伏电站发电效率快速估算实用模型

光伏电站运行性能的最终指标是系统效率。基于光伏电站的系统结构和能量传输过程,将光伏电站系统分为3段,建立了发电效率快速估算模型。以内蒙古某20 MW光伏电站为例,通过其简单易得的监控数据计算出每一段的效率,将各段效率相乘,估算出该电站发电系统总效率约为88.78%。此外也大致得出了光伏组件、逆变器和变压器等关键设备的工作情况,可为电站的后期运维以及管理提供一定参考。     

基于ArcGIS与多因子模型的光伏电站选址评估

该文基于中国光伏资源的时空分布，研究并提出一种基于ArcGIS与多因子评价的光伏电站选址及发电潜力预测模型。利用ArcGIS软件与层次分析法，综合考虑多种影响大型光伏电站建设的因素，对不同地势和土地类型赋予不同的光伏利用系数，得到大型光伏电站建设适宜度、光伏潜力与光伏电站选址的多因子评价模型。基于该模型得出中国光伏发电潜力并给出光伏电站选址建议。评估结果表明，全国年光伏总发电量约为570.07×10⁶kWh，其中新疆为年光伏总发电量最高的省份。中国较为适宜建设光伏电站的地区主要为西北部地区，其中适宜区面积为1.08×10⁶km²，最适宜区面积为2.10×10⁵km²，研究可结果将为中国光伏产业长期的规划与建设提供可靠的理论依据。     

Challenges to China's transition to a low carbon electricity system

We examine the challenges to China's transition to a low carbon electricity system, in which renewable energy would play a significant role. China's electricity system currently lacks the flexibility in planning, operations, and pricing to respond to conflicting pressures from demand growth, rising costs, and environmental mandates in a way that simultaneously maintains reliability, decarbonizes the system, and keeps prices within acceptable bounds. Greater flexibility crucially requires the ability to more systematically and transparently manage and allocate costs. This will require re-orientating sector institutions still rooted in central planning, and strengthening independent regulation. Some of the necessary changes require fundamental political and legal reforms beyond the scope of energy policy. However, the system's flexibility can still be increased through the development of traditional planning and regulatory tools and approaches, such as an avoided cost basis for energy efficiency investments, more integrated planning to improve the coordination of generation, transmission, and demand-side investments, and a transparent ratemaking process. The judicious application of OECD electricity sector experience and skills can support these developments.     

Geothermal power production in future electricity markets—A scenario analysis for Germany

Development and diffusion of new renewable energy technologies play a central role in mitigating climate change. In this context, small-scale deep geothermal power has seen growing interest in recent years as an environmentally friendly, non-intermittent energy source with large technical potential. Following the first successful demonstration projects, the German geothermal industry is currently experiencing an internationally unparalleled growth. In this study we explore the factors driving this development, and the role geothermal power production could play in the future of the German electricity market. For this, we apply the scenario technique, based on literature analysis and interviews with companies operating actively in the field. Our findings highlight the importance of political support and framework conditions in the electricity market, with the best prospects in a decentralised energy system based on renewable energy sources, where high investment costs and the risk of discovery failure are balanced by the benefits of low-carbon base load power.     

Integration of large-scale hydrogen storages in a low-carbon electricity generation system

This study investigates the overall feasibility of large energy storages with hydrogen as energy carrier onsite with a pre-combustion carbon capture and storage coal gasification plant and assesses the general impacts of such a backup installation on an electricity generation system with high wind power portion. The developed system plant configuration consists of four main units namely the gasification unit, main power unit, backup power unit including hydrogen storage and ancillary power unit. Findings show that integrating a backup storage in solid or gaseous hydrogen storage configuration allows to store excessive energy under high renewable power output or low demand and to make use of the stored energy to compensate low renewable output or high power demand. The study concludes that the developed system configuration reaches much higher load factors and efficiency levels than a plant configuration without backup storage, which simply increases its power unit capacity to meet the electricity demand. Also from an economical point of view, the suggested system configurations are capable to achieve lower electricity generation costs.     

An investigation of the effect of changes of planning criteria on power system expansion planning with a case study of the Jordanian power system

Many factors contribute to the planning process of power systems. In the context of expansion planning, focus is paid to selection criteria that enable the optimization of related factors that will result in the best performance. This is described as meeting demand whilst reducing costs and maintaining minimal risk in operation. In this paper, different criteria used in the planning of power system expansion studies are investigated with the objective of identifying their impact on the expansion plan. The results of these criteria on the expansion study of the Jordanian power system are presented. Results show good correspondence to the actual adopted solutions. The spinning reserve is the most influential planning criterion on the overall system expansion cost. This is followed by the peak load changes, and the forced outage rate of the candidate units used for capacity additions to meet future expected demand. Finally, the loss of load expectation and cost of energy not served have the least effect on the overall system expansion cost. These results highlight the importance to be placed on performing sensitivity analyses to determine the most cost effective and acceptable expansion plan of the electric power system. There is a need to continually update the planning criteria to cater for changes and developments in the power system and the economic situation. Finally, the methodology of this study can be generalized to other power systems.     

Application of cool storage air-conditioning in the commercial sector: an integrated resource planning approach for power capacity expansion planning and emission reduction

An assessment is presented of the evaluation of the application of cool storage air-conditioning (CSA) in the commercial sector as a resource in the electricity generation expansion planning. The resultant impacts of analysis of emission costs on annual emissions from power generation are also discussed. A building energy simulation tool is used for assessment of potential savings and peak load shifting of CSA application in commercial buildings. In this study, an integrated resource planning (IRP) model is used to evaluate the economic effectiveness of the CSA option. The IRP analysis with emission costs results in deferring the installation of four units of 1000-MW coal-fired power plant from 2010 to 2011, and one unit of 1000-MW coal-fired power plant and one 200-MW CSA option are removed from the IRP plan. Results show that the CSA option is a viable resource in the least-cost planning and reducing environmental emissions.     

迎峰度夏电荒煤荒的困境与对策

本文对我国2003年以来年年迎峰度夏部署却年年出现电煤紧张、拉闸限电的困境原因进行了深入分析,认为根本原因是宏观调控战略处于不合理状态,并就煤炭电力规划、电煤库存制度、煤电价格机制、官员政绩考核和打破国有电力垄断等多方面提出了改革建议。     

The economics of large-scale wind power in the UK A model of an optimally mixed CEGB electricity grid

Previous calculations of the economics of large-scale wind power have been generally limited to the evaluation of the marginal cost of energy, assuming that the addition of a wind farm to an electricity grid does not change the mix of base, intermediate and peak load plant in that grid. Here a simple but powerful numerical generation planning model has been constructed for grids containing wind farms and three classes of thermal power station, but no storage. Electricity demand and available power are specified by empirically based probability distribution functions and the plant mix which minimizes the total annualized costs of the generating system is determined. Capacity credit of wind power is automatically taken into account in the optimization. Using the model, the breakeven costs of wind energy in a model British CEGB grid, containing coal, nuclear, oil and wind driven power plant, are evaluated under various conditions. For a wide range of parameter values, large-scale wind power is likely to be economically competitive in this grid.     

基于电源优化扩展规划的抽水蓄能电站经济评价方法研究

为了合理评价抽水蓄能电站的经济合理性和财务可行性，提出了基于电源优化扩展规划的抽水蓄能电站经济评价方法，以河南省宝泉抽水蓄能电站为例，进行了河南电网2000-2015年的电源优化扩展规划计算，在此基础上对该电站进行了经济评价。     

计及储能系统的微电网优化调度模型

为了缓解含风电、光伏等新能源微网并网对系统安全运行的影响,提出了在分时电价下,考虑储能系统的微网优化调度策略。以微网总成本最低为目标,分别考虑了投资成本、污染惩罚成本及主网购电成本,建立了微网主网联合运行优化模型,并以典型日负荷出力情况为例分析了不同情景下的优化结果。算例结果表明,所提策略和模型能有效实现微网优化调度,有效降低了含电动汽车和蓄电池等储能设备的微网年运行成本,同时能够保障微网和主网的联合安全运行。     

风/光/柴多能互补发电系统优化配置研究

为实现风/光/柴多能互补发电系统的经济运行,应用启发式算法以分布式发电投资、运行费用、向输电系统直接购电费用以及考虑环境因素费用总和最小为优化目标,分别对并网型和离网型两种情况进行规划和运行的综合分析,从而确定各DG类型的最优投入容量。研究结果表明:该模型可以全面评估分布式发电的经济性能,并对不同运行方式给出相应的最优配置方案,从而极大地提高系统的供电可靠性和经济可行性。