Electric cooperatives and the political economy of rural electrification in Africa: Insights from Uganda

Rural electrification is a crucial process of enhancing the modern energy access of rural communities which is an important global development goal. Electric cooperatives have played an important role as drivers of rural electrification worldwide, both historically and contemporaneously. The emerging role of cooperatives in rural electrification is yet to be examined in the context of East Africa, a region that experiences serious infrastructure deficits alongside widespread rural poverty. This study adopts a political economy perspective to explore the roles and challenges of cooperatives in rural electrification in Uganda. Through a high-level case study of two electric cooperatives, we show that while the cooperatives can deliver rural electrification, they face a series of political and economic challenges in fulfilling their mission. To enhance rural electrification through cooperatives, the challenges should be addressed by policy solutions: (1) providing more support to rural households that cannot afford electricity; (2) providing further support to cooperatives to avoid overburdening the community; (3) enhancing investment to upgrade the grid and extend its geographical coverage; and (4) exploring new financial and technological options for rural electrification. We expect the findings of this study to be useful to policymakers, implementers, cooperatives, and international donors currently working in rural electrification in Africa and beyond.     

Rural electrification and expansion planning of off-grid microgrids

This paper presents the past and current practices for rural electrification and the current trend in using off-grid microgrids to provide energy to the customers with no access to the central electricity network. The challenges correspond to the capacity expansion of off-grid microgrids including the financial and business models for establishing these technologies, the economic and reliability considerations, the environmental issues, the expansion and feasibility studies, and the uncertainties in the operation horizon were presented.     

基于微网技术的家庭能源管理系统研究

家庭能源管理系统是未来智能电网在配电侧发展的重要研究方向。以包含光伏发电、蓄电池储能和家庭负荷的家庭直流微电网系统为研究对象,研究了各个单元的基本控制策略,并提出了基于微网技术的家庭微网能量调度策略。系统的工作模式包括并网工作模式和离网工作模式,通过能量调度策略来维持系统功率平衡和直流电压稳定。在Matlab/Simulink下搭建了家庭直流微网系统并对该控制策略进行仿真验证。仿真结果表明,系统在并网运行模式和离网运行模式下均能保持直流侧电压稳定,验证了家庭能源管理系统的正确性和有效性。     

Rural electrification implementation strategies through microgrid approach in South African context

Rural electrification requires high initial capital investments per capita due to its low energy demand and population density. These factors result in a higher cost of electricity than that for urban consumers. Although the solution to the majority of rural electrification financial challenges are with government policymakers, it is equally important for rural electrification project implementers to understand the technical challenges and identify any cost reduction potential. This paper proposes and compares a diverse set of standalone electrification strategies for a variety of consumer load types in the Sdakeni rural area in the Eastern Cape Province in South Africa. The aim of this research is to compare the electrification strategies based on: cost, efficiency, performance, equipment utilization factor, excess electricity produced etc. Based on the findings from the comparison, the paper will provide insight into suitability of such strategies and act as a guideline for balancing cost optimization process and design robustness of such systems. It will also provide recommendations on future research along this line which would include aspects that could not be covered in this work.     

中国农村能源发展关键问题

近年来,中国农村能源供应保障能力不断增强,能源结构调整成效明显,但是也存在一些问题：农村废弃物能源化利用率低制约了资源综合利用和环境保护,农村能源消费层次低和电气化水平不高制约了城乡快速融合发展和农村地区能源消费升级,农村能源社会化服务体系建设滞后制约了农村能源有效供给和高效服务的社会公平。针对中国农村能源发展面临的问题和挑战,聚焦农村生活用能,梳理分析了中国农村能源发展基本情况。针对中国国情的特殊性和不同区域具体特点,通过对农村废弃物能源化利用、农村能源电气化应用、农村能源服务体系建设等关键问题研究,提出了促进中国农村能源科学发展的措施建议。     

基于储能荷电状态的主从控制微电网离网协调控制策略

双碳和新型电力系统建设目标下集成优化资源的微电网将是电网公司实现该目标的重要载体。微电网支持并网或离网运行,其离网运行可以提高供电可靠性,这是微电网的重要特性。离网运行的微电网需要合适的稳态控制策略,以保证微电网的长期稳定运行。目前一些依赖预测信息和采用模糊智能算法的能量管理方法在微电网的长期实际运行中会产生较大的稳态控制误差。为了更好地解决微电网离网运行时电力电量平衡定量的计算问题,提高微电网离网稳态控制精度,研究了基于储能电池荷电状态的主从控制微电网离网实时稳态协调控制策略,提出了微电网离网有功协调控制间歇电源调整、负荷调整、微电网停运等关键操作中储能荷电状态控制节点值的精确工程计算方法。针对实际微电网应用工程开展了协调控制策略的具体应用,仿真和实际运行证明了所提控制策略和计算方法的有效性。     

内蒙古电力科技园智能微电网运行特性研究

对内蒙古首个智能微电网——内蒙古电力科技园智能微电网进行了并网转离网试验,结果证明:当主网失电时,借助储能系统,微电网可以在7 s内完成由并网转离网模式切换。作为网内扩容的前期研究,比较了12个月微电网内2种额定功率均为10 kW的光伏及风力发电系统的发电情况,前者月均发电量比后者高82.5%,因此建议后续微电网电源的接入选择应以光伏系统为主。设计了一种离网的电动汽车充电方案,并使用网内RLC负载模拟电动汽车进行30min的充电试验,从功率平衡角度证实了该充电方案的可行性。     

农村电气化建设及农村用电发展趋势分析

介绍了国外农村电气化发展情况,总结了我国农村电气化的发展历程,结合我国社会主义新农村电气化建设目标,分析了我国农村用电的发展趋势和特点,提出了加快新农村电气化建设的有关建议。     

优化能源消费结构提高能源使用效率

我国经济发展已进入工业化中期阶段,经济高速发展和经济结构重型化特征使得能源需求强劲增长,给我国的能源供应和环境带来极大挑战,优化能源消费结构,提高能源效率成为应对能源供应压力的关键因素.通过量化分析不同发展阶段我国及国外发达国家电气化发展水平与能源消费强度之间的关系,重点阐述了提高电气化水平可有效推动能源使用效率的提高.结合我国以煤为主的能源资源特点,提出了优化能源消费结构的重点应是大力推动煤炭向电力的转化,提高电力在终端能源的消费比重,以此来促进能源效率的提高,从而减少能源消费总量并减少环境污染.     

中国发展微网的目的方向前景

从中国能源利用和电网建设的背景出发,针对分布式电源接入、可再生能源利用、农村电气化、用户电能质量需求、电力系统抗灾能力以及与智能电网的关系等6个问题阐述了中国发展微网的目的.分析了发展微网应以包容性、灵活性、定制性、经济性、自治性作为基本方向.指出了在建设坚强智能电网的战略框架下,微网在中国具有广阔的技术前景和应用前景.     

考虑EV负荷的微电网多主体联合容量优化配置方法

随着可再生能源(renewable energy,RE)、智能电网、电力运输等环保技术的快速发展,未来的发电和供电展现出新特点。现代电力系统的能耗特性设计要求更灵活,更易于控制,因此促进了灵活可控的分布式电源快速发展。本文介绍了一种包含太阳能光伏(solar photovoltaic,PV),风力涡轮机(wind turbines,WT),柴油发电机(diesel generators,DG)和电池储能系统(battery energy storage system,BESS)的典型独立微电网(microgrid,MG)的联合容量优化方法。MG提供住宅社区负荷,包括典型的住宅负荷和电动汽车(electric vehicles,EV)充电负荷。建立PV、WT、柴油发电系统、BESS和EV充电负荷的实际数学模型以改进容量优化方法,其涉及与可再生电源、柴油发电系统、BESS和EV负荷相关的各种实际约束。研究目标包括：1) 最小化成本;2) 减少温室气体排放;3) 减少弃能。此研究可以为微电网容量优化配置提供有力支撑。     

基于3E能源优化模型的中国电气化进程研判及定量分析

能源生产消费的电气化既能够承载新能源高效转化,又可以推动能效总体水平提升,是全球能源转型的战略选择。在明确电气化推动能源转型的基础上,分析中国持续提升电气化水平的基本条件,通过国际比较研判了未来全球电气化进程趋势,采用能源电力规划模型以及能源消费预测模型,研究提出了中国再电气化发展战略路径,为推动中国能源转型、有效促进电气化发展提供了决策支撑。     

The democratization of electricity in Nigeria

Nigeria’s aspiration towards universal access to electricity has been hindered by a centralized and closed grid system. The country took steps in the right direction by recently unbundling and privatizing the state-owned electric power utility and introducing a renewable energy feed-in tariff and mini-grid regulations. The author advocates a full-scale democratization of the electricity sector to empower local communities and small, stand-alone producers to participate in solving the electricity crisis.     

The legal sustainability of energy substitution in Nigeria’s electric power sector: renewable energy as alternative

Non-renewable fuel sources have been the predominant energy sources and a significant source of foreign exchange income for Nigeria, while at the same time there is a severe problem of electricity inconsistency and persistent power blackouts in Nigeria. The research aims to end the concern for deficient energy use, and to encourage energy efficiency and sustainability. Nigeria has not maximized the advantages of renewable energy after the denationalisation of its electricity industry despite the current transformation in the power industry and the rising demand for renewable energy supply. The research adopts a doctrinal legal approach with a library-based legal research technique with a comparative legal method. It reveals that the absence of a comprehensible legal regime with encouragement for the use of renewable energy is the fundamental element causing the slow utilization of renewable energy as a substitute source of energy in Nigeria. It is suggested that, among other reforms, there is a need for a comprehensible legal regime on renewable energy and the encouragement of strict implementation of energy regulatory strategies and policies with incentives for the application of renewable energy sources in Nigeria.     

计及微电网并离网两种工况的储能容量优化配置

对于并网型微电网的容量配置需同时考虑并离网状态。离网工作时,单靠储能满足微电网长时间内的能量平衡,往往配置容量较大且经济性欠佳。针对离网状态,提出了一种考虑充放电倍率特性的储能与柴油发电机协同配置方案,同时计及了电池的寿命模型。分别给出离网时考虑切负荷率的每个时段储能、柴油机联合出力模型,以及并网时考虑削峰填谷每个时段储能、联络线联合出力模型。以切负荷率和切负荷期望为指标参数,经济性和电网依赖度为优化目标,采用磷酸铁锂电池进行容量配置。最后,采用实际工厂数据进行仿真计算,验证了方法的合理性。     

智能微网运行的低碳综合效益分析

从用电侧的能源条件和负荷需求入手,设计规划了智能微网主要发电单元的装机容量,并从经济性和低碳化两个方面分析了智能微网运行的效益形成机理,进而利用低碳经济要素将两方面效益统一,提出了低碳综合效益的概念.结合智能微网的建设成本,建立了智能微网运行的低碳综合效益分析模型,阐述了以低碳综合成本最低为目标的智能微网日前调度原则,并依据典型的智能微网设计方案所提出的模型对智能微网的投资收益情况进行了分析.结果表明:智能微网的运行方式与传统电网相比,有着很大的低碳综合效益优势;参与到电网互动的智能微网,能够发挥其成本调节作用和灵活运行能力;未来通过降低分布式能源的发电成本,优化电力市场电价系统,加快低碳经济的开展,可达成智能微网运行的经济性与低碳性的高度统一     

含新能源微电网负荷响应的二阶电力模型研究

随着全球性的能源紧张,新能源已成为替代传统化石能源的重要手段,当新能源的随机性给电网调度带来新的挑战。以新能源接入微电网为例,建立一种两阶段的电力市场模型,并提出一种需求侧响应定价策略。模型第一阶段针对新能源预测出力,在预测需求侧响应基础上,确定微电网出清电价。第二阶段在新能源随机处理,各用户提出的需求侧响应基础上,确定微电网调整电价。算例分析的结果表明,所提模型能够利用用户不同的需求侧响应曲线,调整系统的负荷水平,从而有利于新能源接入。     

农村电工现状调查及解决对策探讨

农村电网容量逐步扩大,农村电工作为电力行业的一个特殊群体,是电力企业与广大农村用户的桥梁和纽带,也是农村电气化事业的生力军。通过对农村电工现状的调查分析,得到现阶段农村电工存在的问题,并提出相应的解决对策。     

计及多时间尺度需求响应资源的微电网能量优化调度策略

随着电力体制改革的深入,用户侧微电网逐渐形成多方投资+集中管控的运营模式,研究计及运营商利益的微电网能量优化具有重要的现实意义。文章提出一种以运营商购售电收益最大化和需求响应补偿成本最小化为目标的微电网能量优化调度策略。该策略计及需求响应多时间尺度特性,将集群空调和集群电动汽车2种需求响应资源纳入日前-日内-实时3种时间尺度调度计划中,并根据各阶段可再生能源预测信息以及电价信号,逐级优化储能出力和需求响应供应量,实现运营商的全局利益最大化。负荷聚集商基于集群空调和集群电动汽车的控制模型预测各时段可控负荷容量并实时响应调度指令。最后,通过算例验证本文所提调度策略的有效性。     

用于提升电–气两网调节能力的微网集群协调运行模型

针对单一多能源微网受能源类型、自身容量制约,难以充分实现多种能源高效利用和协调控制的问题,该文基于多能源微网能量交互策略建立可提升电-气两网调节能力的微网集群优化运行模型。首先建立以电热冷、电气氢、电热气氢、电热冷气氢等不同能源类型运行时多能源微网能量供给、转换特性的统一模型;然后在统一模型的基础上,建立满足电-气两网调节需求的多能源微网集群系统运行优化模型;随后以多能源微网集群的总运行成本最小和能源利用效率最大为优化目标,使用改进的区域局部搜索NSGA-Ⅱ算法(NSGA-Ⅱ-RLS)对建立的微网集群优化模型进行求解;最后,基于改进的IEEE14节点系统和天然气网络6节点系统,构建可提升电–气两网运行调节能力的多能源微网集群运行仿真模型。仿真结果表明,所提多能源微网集群系统能够有效提升电-气两网调节能力,实现多能源微网集群系统的多能互补运行。