Are Energy Management Systems Cost Effective?

While the market for energy management systems (EMS) has been exploding, there are many indications that the pendulum of high expectations may have swung too far. A simple seven-day time clock can usually provide 80-95 percent of the potential savings of many EMS features. For several hundred additional dollars, a small microprocessor based time clock with features such as automatic holiday and daylight savings adjustments, optimal start, and four separate load stop/start schedules (ventilation, heating, and air conditioning, indoor lights, and outdoor lights) can be purchased which can increase the savings an additional 5-20 percent on most buildings. Owners of multiple building systems or large commercial and industrial buildings can often justify a complex EMS with increased load scheduling capability. However, EMS features such as duty-cycling and demand limiting are usually overrated in their energy savings capability, not only because slowing down the fans can save more energy than cycling them, but also because duty cycling can cause personnel discomfort and equipment maintenance problems. Moreover, any temperature control modifications which save energy can usually be installed without an EMS for less initial cost and with an equivalent energy savings. Additional expenses for EMS features such as temperature monitoring and remote set point adjustment are not usually of value if a building's heating, ventilating, and air conditioning (HVAC) system is operating properly. EMS features such as metering and report logs can be useful diagnostic tools in the hands of a qualified individual, but often they provide data diarrhea.     

Economic Analysis of Hybrid Battery Energy Storage Systems Applied to Frequency Control in Power System

The battery energy storage system (BESS) is prospective energy storage in the smart grid, and the hybrid energy storage system (HESS), using two different kinds of battery, is also being studied to achieve better performance and the lower cost than the single‐battery‐type BESS. However, the cost issue has not yet been evaluated explicitly. On the other hand, BESS has been studied and offers promise for ancillary service, although HESS has not been applied to frequency control in power systems. This paper focuses on the application of HESS to frequency control and its economic analysis. In this paper, the important battery characteristics in the application to a power system are introduced and two kinds of HESS are evaluated in terms of their cost when applied to frequency control. In addition, the cost HESS is used for peak shift as well as frequency control is analyzed.     

公共楼宇可调负荷资源调控技术研究综述

公共楼宇的大量负荷属于需求侧可调负荷资源,且参与电网互动时的精细化调控潜力尚未得到充分挖掘。文中对公共楼宇的负荷进行分类,对公共楼宇典型可调负荷资源的用能行为特征、用能模型、调控模型与调控策略的关键技术及其研究现状进行归纳总结,给出了公共楼宇可调负荷资源用能行为特征的分析框架与特征指标体系。考虑到公共楼宇可调负荷资源是参与区域综合能源服务(Integrated Energy Services, IES)与虚拟电厂(Virtual Power Plants, VPP)的重要组成部分,因此对多能异构的负荷资源协调管控技术开展了深入研究并进行综述。文中的研究工作将为公共楼宇可调负荷资源参与需求侧响应(Demand Response, DR)与电网互动奠定良好的理论基础,为相关研究提供一些有价值的参考。     

德国能源效率政策措施

提高能源效率是实现降低全球温室气体排放目标最快和最有效的方式之一。德国政府制定了多种政策措施,以减少二氧化碳排放。为提高交通运输业能源效率,德国采用资金奖励和征税并举的措施;为提高建筑物的能源效益,采取复兴信贷银行直接管理项目的方式;德国重视工业能源效率,设立资金激励机制鼓励中小企业提高能源效率。     

考虑可再生能源参与的调峰交易机制设计

长期以来,可再生能源一直被认作系统调峰资源的消费者,不能主动参与电力调峰。针对中国当前电力体制、市场机制和电力调度方式,探讨了调峰概念的定义和内涵,指出其具有普遍性、多样性、经济性、持续性和指向性5个显著特征,分析了各类资源提供调峰的效益与优势,在此基础上指出了可再生能源参与调峰交易的可能性和必要性。从调峰服务5个特征的角度,评述了国内已开展的调峰补偿和交易机制,并针对中国现货市场建立之前的过渡期,以理想调峰曲线作为调峰贡献的参照基准,以单位时段内上下调整功率作为交易标的,设计了考虑可再生能源参与的调峰市场交易机制,以期通过调峰交易激励各类资源提供调峰,促进可再生能源消纳和节能减排。算例分析表明了该交易机制的有效性和可行性。     

基于需求侧响应的分布式冷热电联供系统能量管理策略

分布式冷热电联供系统(distributed combined cooling,heating and power system,DCCHP)因其高效的能源利用率成为区域综合能源系统的有效实现形式,同时随着需求侧响应(demand response,DR)技术的发展,通过管控用户用能行为来提高能源系统性能成为目前研究的热点。基于此,文章建立了区域能量管理系统(regional energy management system,REM S)并提出了一种基于DR的DCCHP能量管理策略。在用户侧,对系统负荷进行分类并建立考虑用户满意度反馈及动态费用补偿的DR控制模型。REMS用能方式管控子系统,针对冷热电负荷各自的特点及组成,以DR补偿费用及负荷峰谷差最小为目标优化初始负荷曲线形态。在供能侧,将优化后的负荷数据输入REMS设备出力调度子系统,以DCCHP综合成本最小为目标经济管控系统设备出力。算例仿真结果证明所提策略可有效提高系统能源利用率、降低成本,实现供需双侧的共同优化。     

面向需求响应业务的灵活弹性传输策略

随着需求响应(demand response,DR)不断深化实践,未来需要依靠高可靠的信息交互支撑精细化的DR控制.然而在DR无线通信场景下,复杂的信道环境极大影响DR高效的信息交互,现有技术难以匹配和满足DR业务的特性.针对DR无线传输中的信道质量问题,设计了面向DR业务的灵活弹性传输策略,该策略通过自适应编码实现....     

考虑天气类型的新型HDP智能楼宇储能优化调度

针对智能楼宇微网系统存在的非线性、时变、分布式发电不确定性等导致的建模困难问题,提出了一种基于启发式动态规划(heuristic dynamic programming,HDP)的储能系统调度算法。在考虑储能系统寿命、用户实时电价(residential real-time price,RRTP)的基础上根据天气分类使用两种神经网络来训练HDP模型,使得它能够适应自身所在环境而进行自我更新。通过与微分进化算法的对比分析,结果表明,所提出的储能优化调度算法能够有效地节约用电成本、避免蓄电池深度充放电,具有良好的经济收益;在与环境的学习过程中逐步寻求最优解的特性使得该算法对模型依赖度低,有效缓解了建模困难问题;在均衡负载、削峰填谷方面也起到了较好的效果。     

Energy saving performance of distributed heating and cooling system

An advanced distributed heating and cooling system utilizing small‐scale high‐performance heat pumps was designed to replace the central heating and cooling system for the AIST laboratory buildings, which have a total floor area of 36,100 m², of which 20,100 m² is occupied by laboratories. In the old system, the total primary energy required for hot water was 44 TJ, and it was 12 TJ for chilled water in FY 2001. The new system is composed of small‐sized high‐performance heat pumps, with an average coefficient of performance (COP) of 3.1. After the reconstruction, the energy consumption was reduced to 37%, and with a total energy saving of 44 TJ for one year. The total CO₂ emission is estimated to be 26%, a reduction of 3000 tons per year. The energy saving is caused by the high‐performance small‐scale heat pumps, the high‐performance total system design that takes laboratory into account, and the suitable operation of the system. © 2010 Wiley Periodicals, Inc. Electr Eng Jpn, 174(2): 46–53, 2011; Published online in Wiley Online Library ( wileyonlinelibrary.com ). DOI 10.1002/eej.20977     

Optimal Energy Management for Smart Grid System Considering Battery Characteristics

This paper discusses optimal energy management considering battery characteristics for smart grid and microgrid systems. Energy storage systems are very important for energy peak shifting and peak load cutting in microgrid and smart grid systems, but optimal battery formulation and energy management in the use of expensive energy storage system and methods of taking account of battery characteristics are still in the developmental stage. First, the optimal battery placement for a smart grid system with lithium‐ion batteries is considered as a means of lifetime extension. The battery choice index for this optimal battery utilization problem of optimal energy management is discussed. Second, a smart grid system with a distributed battery system for grid frequency control with consideration of distributed control and battery characteristics is discussed. Optimal controllers for distributed battery systems to reduce the battery load and to expend the battery lifetime are designed. Simulations are used to demonstrate the effectiveness of the proposed method in comparison with conventional methods.     

A Service Business Model for Saving Energy and Reduction of CO2 Emissions Using Inverters

This paper considers the effectiveness of the service business approach for reducing CO₂ emissions. “HDRIVE” is a service business using inverters to reduce the energy consumption of motor drive. The business model of this service is changed to find new opportunities of CO₂ emission reduction by combining various factors such as financial services or long‐term service contracts. Risk analysis of this business model is very important for providing stable services to users over the long term. The HDRIVE business model is found to be suitable for this objective. This service can be applied effectively to industries such as chemicals or steel, where CO₂ emissions are very large, and has the possibility of creating new business considering CDM or trading CO₂ emission rights. The effectiveness of this approach is demonstrated through several examples in real business. © 2012 Wiley Periodicals, Inc. Electr Eng Jpn, 179(3): 40–48, 2012; Published online in Wiley Online Library ( wileyonlinelibrary.com ). DOI 10.1002/eej.21242     

面向能源互联网的多能流综合能量管理系统:设计与应用

能源互联网是当前国内外学术界和产业界关注的热点和创新方向,其中一个焦点是研制多能流综合能量管理系统(IEMS)。在简要回顾能量管理系统(EMS)发展历程的基础上,设计并研制了面向能源互联网的IEMS,通过多能互补和源网荷储协同,实现安全供能前提下的效益最大化。阐述了所研制的IEMS的主要功能,并通过示例展现了其应用效果,该IEMS系统已经在几个能源互联网的示范项目中得到现场应用。     

国外促进新能源消纳的典型市场机制分析

新能源消纳问题正在困扰着中国电网,由于电源结构、电网输送能力、新能源增速等多重原因导致了中国弃风弃光问题日益突出。首先分析造成中国新能源消纳问题的主要原因,在总结新能源保障性消纳和参与市场2种消纳方式的基础上,介绍5种国外促进新能源消纳的典型市场机制,包括新能源发电预测、电量偏差处理机制、调峰机制、跨区跨国消纳机制、可再生能源配额制。结合上述国外市场机制,分析中国新能源消纳市场机制现状,最后从提升预测水平、建立市场机制、偏差电量处理、调峰辅助服务、扩大消纳范围等方面为中国新能源消纳给出具体建议。     

Determination of the optimal DR capacity for a commercial building with chiller system and energy storage system

Demand response (DR ), which is used to shave the peak demand for securing supply reliability in a power system, is one of the promising constitutions for the end users. In a commercial building (COB ), the most popular adjustable DR resource (DRR ) is the chiller system. More specifically, its power consumption can be reduced by thermal mass control (precooling) in a specified DR duration. On the other hand, installation of energy storage systems (ESSs ) is going on at an accelerated pace because of its high economic efficiency. ESSs have been used for peak‐shift operation under the time‐of‐use (TOU ) tariff. However, ESS can be also used as an attractive DRR because it can reduce the net load by discharging the ESS for a specified DR duration. Based on this background, this paper presents a method for determining the optimal DR capacity in a COB with a chiller system and ESS . In the proposed scheme, the optimal DR capacity (kW ) can be determined so that the total expected cost of a COB becomes minimum by using the chiller system and ESS while avoiding the DR penalty threat adopted in the Korean DR market. Uncertainty in the ambient temperature, the amount of reduction, and DR durations are considered as the scenarios. The estimation and economic evaluation of the proposed scheme is ascertained through case studies. © 2017 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc.     

考虑用户效用评价的园区多能供给服务能量管理及定价策略

随着我国能源市场的逐步开放,综合能源服务得到广泛关注,而园区多能供给服务是其重要的发展趋势之一。在此背景下,以多能供给服务商管理园区综合能源系统为应用场景、服务商和用户为博弈参与者、服务商净收益和用户综合效用为目标函数, 建立考虑用户效用评价的服务商能量管理及定价策略的主从博弈模型。通过组合赋权法得到用户综合效用函数,构建含电、热、冷、气4类负荷的用户模型,并结合服务商收益优化模型,提出服务商和用户主从博弈定价机制,通过双方的互动博弈, 动态改变双方策略,得到博弈均衡结果。最后通过算例分析证明了所提能量管理及定价策略具有合理性和有效性。     

能源大数据信息服务定价及其在电力市场中的应用

随着能源技术发展和能源网络的复杂化,能源大数据信息化成为趋势。在市场经济条件下,能源市场化的形成,使数据信息成为一种极其重要的商品。鉴于此,该文紧密联系能源互联网与信息服务,研究能源大数据的信息服务定价,梳理了能源大数据信息服务定价流程,提出了信息服务产品内容和应用模式,并给出了在电力市场中的应用,为将来能源互联网中信息服务应用体系的规划和建立,实现数据流的价值创造提供有益的参考。     

一种新型的电力监测和能量管理系统

针对我国电力系统自动化的现状 ,提出了一种新型高效的系统管理模式———电力监测和能量管理相结合的系统。分析了该系统的功能 ,并对部分模块的算法和功能实现进行了深入探讨 ,根据用户的不同实际需求 ,结合计算机软件系统的发展现状 ,在实时监测、网络拓扑结构和数据整合方面提出了一些新的系统模式。     

Energy storage system utilizing large‐capacity electric double‐layer capacitors for peak‐cut of power demand

Recently, due to a rapid increase of demand for air conditioning in summer, peak power demand is becoming increasingly acute. Therefore, the load factor has a tendency to drop every year. The drop of the load factor is leading to a drop in the utilization factor of the power facilities and an increase in the cost of installation. In this paper, we propose an energy storage system for peak‐cut of power demand, in which we use large‐capacity electric double‐layer capacitors. This energy storage system has some distinctive characteristics, including long life span, maintenance‐free operation, preservation of environment, high efficiency at charge/discharge, and so on. This paper deals with the circuit arrangement of the proposed energy storage system, the charge equalization method of the capacitors, and the control method of the converter at charge/discharge. Finally, the operating characteristics of this system are evaluated by simulation analysis. © 2000 Scripta Technica, Electr Eng Jpn, 133(3): 83‐92, 2000     

参与辅助服务的用户侧储能优化配置及经济分析

为使用户侧储能收益最大化,提出了一种参与辅助服务市场的用户侧储能优化配置方法。首先,建立了用户侧储能的全生命周期成本和考虑辅助服务的收益模型;其次,在两部制电价下,基于对储能电池运行特性和用户负荷特性的考虑,建立了一种参与辅助服务的用户侧储能优化配置模型,以储能容量和辅助服务参数为优化变量,对工业用户全寿命周期的净收益进行优化计算;然后,以广西储能辅助服务市场为例,实现了用户侧储能最优容量下的配置优化,确定了参与辅助服务的变量值;最后,通过改变政策敏感度对比分析了不同辅助服务的经济效益,给后续储能投资提供了指导性意见。     

Energy Conservation in the Bell System

The nation and telecommunications systems are confronted with a continuing energy problem resulting from limited resources to meet an ever increasing demand. The Bell System provides numerous examples of ways in which demand for energy may be reduced, resulting in conservation of resources and preservation of the environment. The Beli System provides a telecommunications network linking nearly 185 million telephones and handling in excess of 765 million calls a day. In providing telecommunications services, the Bell System employs over one million people, utilizes almost 29 000 buildings, and operates over 194 000 motor vehicles (the world's largest owned and operated private fleet). However, the Bell System is not energy intensive. It uses only about one-tenth of 1 percent of the nation's energy, while contributing over 2 percent of the gross national product.