一种新的基于需求侧响应下光储微电网运行策略

为了能达到光储微电网经济效益最大化,以及在经济效益最大化的同时,保证光储微电网的稳定性。从而提出一种新的基于需求侧响应下光储微电网运行策略即通过调整可转移负荷的工作时间,对可转移负荷进行重置安排,减少配电容量,以及利用不同用电时段制定不同的电价制度即分时电价,人为调控电力需求量,实现削峰填谷的效果,从而提高微网的稳定性。为了使得微电网有最大的经济收益,利用博弈论的方法,继而找到转移负荷用户、分时电价用户、储能方的Nash均衡点。     

Efficient Switched Thermoelectric Refrigerators for Cold Storage Applications

We present switching methods that make thermoelectric refrigerators efficient and optimal for all cold storage applications. These temporal methods double the coefficient of performance (COPs) of the refrigerators during cooling transients and allow highly energy-efficient operation in the steady state by turning off the thermoelectric devices both electrically and thermally so as to avoid back-conduction of heat through the devices. We describe thermoelectric refrigerator cooling engines that attain these enhancements without using any unreliable mechanically moving switching components such as pumps. These switching techniques can provide a fivefold reduction in energy consumption of cold storage refrigerators.     

Solar based large scale power plants: what is the best option?

There are very few published data comparing performance and cost of thermal and photovoltaic (PV) based solar power generations. With recent intense technology and business developments there is a need to establish a comparison between these two solar energy options. We have developed a simple model to compare electricity cost using these two options without any additional fuel source of hybridization. Capital along with operation and maintenance (O&M) costs and other parameters from existing large scale solar farms are used to reflect actual project costs. To compete with traditional sources of power generation, solar technologies need to provide dispatchable electric power to respond to demand during peak hours. Different solutions for energy storage are available. In spite of their high capital cost, adding energy storage is considered a better long term solution than hybrid solar systems for large scale power plants. For this reason, a comparison between the two solar options is also provided that include energy storage. Although electricity storage is more expensive than thermal storage, PV power remains a competitive option. Expenses related to O&M in solar thermal plant are about ten times higher than PV, an important factor resulting in higher energy cost. Based on data from proven commercial technologies, this study showed that PV holds a slight advantage even when energy storage is included. Copyright © 2010 Crown in the right of Canada. Published by John Wiley & Sons, Ltd.     

Battery energy storage technologies

Battery energy storage systems, comprising lead-acid batteries, power conversion systems, and control systems, are discussed. They are used by power generating utilities power distributing utilities, and major power consumers (such as electric furnace foundries). The principal advantages that battery energy storage systems offer generating utilities are described, including load leveling, frequency control, spinning reserve, modular construction, convenient siting, absence of emissions, and investment deferral for new generation and transmission equipment. Power distributing utilities and major power consumers can avoid costly demand changes by discharging their batteries at peak periods and then recharging with lower cost off-peak power (say, at night). Battery energy storage systems are most cost-effective when designed for discharge periods of less than 5 h; other systems (for example, pumped water storage) are better suited for longer discharges. It is estimated that by the year 2000 there will be a potential need for 4000 MW of battery energy storage     

Renewable and Storage Energy Integration for Smart Grid Housing

This paper presents the design,implementation and testing of an embedded system that integrates solar and storage energy resources to smart homes within the smart microgrid.The proposed system provides the required home energy by installing renewable energy and storage devices.It also manages and schedules the power flow during peak and off-peak periods.In addition,a two-way communication protocol is developed to enable the home owners and the utility service provider to improve the energy flow and the consumption efficiency.The system can be an integral part for homes in a smart grid or smart microgrid power networks.A prototype for the proposed system was designed,implemented and tested by using a controlled load bank to simulate a scaled random real house consumption behavior.Three different scenarios were tested and the results and findings are reported.Moreover,data flow security among the home,home owners and utility server is developed to minimize cyber-attacks.     

Minimizing Energy Cost of Air Conditioner in a Residential House under Demand Side Response Model

This research is aimed to develop a consumer demanding side response model to assist electricity consumers to mitigate peak demands during the peak season. The main contribution of this research is showing that consumers can mitigate peak demands by optimizing energy costs of an air conditioner (AC) when a spike happens. It may only occur in a one and a half hours spike during the peak season. This model also investigates how AC applies the pre-cooling method when there is a substantial risk of a price spike. The results indicate that the potential benefit of the model is achieving energy savings for consumers and aggregators, also reducing electricity bills for the consumers. The model is tested with selected characteristics of the room, and based on the standard room in a residential house in Makassar, a city of Indonesia.     

Demand Side Management for Thermally Activated Building Systems Based on Multiple Linear Regression

The building sector and its heating and cooling represent one of the major consumer of energy worldwide. Simultaneously, the share of fluctuating generation of renewable energies in the energy mix increases. Therefore storage and demand side management technologies are required. The new adaptive and predictive control algorithm for thermally activated building systems (TABS) based on multiple linear regression (AMLR) presented in this paper enables the application of demand side management (DSM) strategies. Based on simulations, different strategies have been compared with each other. By applying the AMLR algorithm, electricity energy cost savings of 38% could be achieved compared to the conventional control strategy for TABS, while increasing the thermal comfort. At the same time, thermal energy demand can be reduced in the range between 4% to 8%, and pump operation time from 86% to 89%.     

Using Restructured Electricity Markets in the Hydrogen Transition: The PJM Case

We examine a hydrogen transition strategy of using excess electric generation capacity in the U.S. midatlantic states during off-peak hours to produce hydrogen via electrolysis. Four different generation technologies are evaluated: combined-cycle natural gas, nuclear power, clean coal, and pulverized coal. We construct hydrogen-electricity price curves for each technology and evaluate the resulting air emissions of key pollutants. Substantial capital investments may be avoided by leveraging off generation assets that would otherwise be built to produce electricity. We also account for the interaction between the production of hydrogen and wholesale electricity prices and demand. Results show that off-peak electrolysis is a plausible but not dominant strategy for hydrogen production; however, there may be a substantial real option value in using the electric power system to transition to a hydrogen economy that may exceed the direct cost savings of producing hydrogen by less expensive methods     

Energy-efficient networking for content distribution over telecom network infrastructure

The use of content-based services over telecom network infrastructures is growing rapidly as user-generated content, over-the-top videos, on-demand videos, personalized TV with CatchUp/PauseLive features, etc. are becoming increasingly popular. To meet the demands of such services, content-delivery networks (or content-distribution networks (CDN)) are being deployed over these telecom network infrastructures in a similar fashion as traditional CDNs. However, with the increasing energy consumption and carbon footprint of the information and communication technology (ICT) industry, these CDNs must be designed to include energy-efficiency measures. Our study presents energy-consumption models, analysis, and content-placement techniques for different types of CDNs over telecom networks to reduce energy usage. Our suggested content-placement strategies exploit variations between storage power consumption and transmission power consumption to achieve energy efficiency. Also, in dynamic traffic scenarios, our content-placement strategies utilize the time-varying traffic irregularities of content-based services. By creating more content replicas during peak load and less replicas during off-peak load, dynamic approaches can save substantial amount of energy. Illustrative numerical examples show a significant improvement in the CDN energy efficiency using these approaches.     

电力系统中储能技术的应用

伴随着社会中的能源应用日益紧张,实现能源节约与储能技术应用,是新能源发展的关键.在电力系统中,更加需要储能技术,在人们的用电需求量逐渐增加的基础上,将储能技术与电力系统发展相互结合,能够有效的避免电力系统中能源浪费,并且推动新能源社会的发展.基于此,在本文中对电力系统储能技术应用进行研究.     

Cold Thermal Storage and Peak Load Reduction for Office Buildings in Saudi Arabia

This paper involves the investigations of the chilled water and ice cold thermal storage technologies along with the associated operating strategies for the air conditioning(AC) systems of the typical office buildings in Saudi Arabia, so as to reduce the electricity energy consumption during the peak load periods. In Saudi Arabia, the extensive use of AC for indoor cooling in offices composes a large proportion of the annual peak electricity demand. The very high temperatures over long summer periods, extending from May to October, and the low cost of energy are the key factors in the wide and extensive use of air conditioners in the kingdom. This intense cooling load adds up to the requirement increase in the capacity of power plants, which makes them under utilized during the off-peak periods. Thermal energy storage techniques are one of the effective demand-side energy management methods. Systems with cold storage shifts all or part of the electricity requirement from peak hours to off-peak hours to reduce demand charges and/or take advantage of off-peak rates. The investigations reveal that the cold thermal energy storage techniques are effective from both technical and economic perspectives in the reduction of energy consumption in the buildings during peak periods.     

Solare Gebäudeklimatisierung — ein Überblick

The narrowness of fossil resources is in contrast to the further rising energy demand for the climatization of buildings. This report gives a short overview of solar cooling and climatization methods which mainly need solar energy to work. These methods considerably contribute to a sustainable resource utilization in an ecological and economic way and to a solution of the problem of the rising demand for electricity.     

基于回归分析的迎峰度夏用电量分析

利用回归分析算法,提出了一种迎峰度夏期间最高气温与日用电量关系分析方法,首先利用皮尔森相关系数对度夏期间的最高气温和日用电量相关程度进行定量分析,然后利用回归分析算法建立最高气温和日用电量的拟合函数,并利用最小二乘法进行求解,得到最高气温和日用电量相关关系的定量分析结果。研究结果表明,提出的度夏期间用电量分析方法能够定量地给出气温变化导致的用电量变化情况,并能根据分析结果对未来几天的日用电量进行准确预测。     

Die Bedeutung kurzfristiger und langfristiger Speichertechnologien in der Energiewende

The energy turnaround in Europe results in a rapid development of renewable energy, especially of wind energy and photovoltaic. Because of the short full load hours it is necessary to install large power capacities. However, these capacities can exceed the peak demand and the storage capacities available, and thus cannot be used adequately. The development of centralized and decentralized storage capacities is necessary on the road to predominant renewable energy supply.     

Wirtschaftliche und energetische Aspekte von Langzeitspeichern

In recent years in Europe electricity production from intermittent renewable energy sources has increased remarkably. This has led to a demand for additional electricity storages to balance the annual fluctuations of electricity generation especially from wind and photovoltaic power plants. In this contribution we analyze which long-term storage technologies are feasible from a technical, energetic and economic point of view. The following technologies are analyzed: pump storages, compressed air storages, hydrogen from electrolysis and the production of methane from electrolysis and reaction with CO₂. The major findings from these investigations are following: pump storage power plants are currently the most favorable long-term storage technology for electricity for energetic and economic reasons. With respect to power-to-gas technologies the efficiencies in the whole conversion chain have further to be improved. From an economic viewpoint it can be stated that there is still potential for technological learning. Compressed air storage power plants could be economically attractive, however, the core problem for Austria is the technical realization because of a lack of proper underground storages, e.g. salt caverns.     

北京某工程水蓄能设计及技术经济分析

在北京某开发区多层厂房工程空调系统设计中,采用了水蓄能的冷热源系统型式,针对该工程的具体情况对水蓄能系统与常规空调系统作了技术经济分析,对水蓄能在实际工程中应用方面进行了探讨。     

夏热冬冷地区既有公共建筑节能方案的设计

根据夏热冬冷地区的气候特征与公共建筑的能耗特点,为减少空调和照明系统能耗进行了相关的节能方案设计.由于空调系统能耗是建筑总能耗中最重要的一个部分,重点分析了与空调系统能耗密切相关的围护结构的节能方案,包括外墙设计、窗体设计和外遮阳设计;简述了新风系统的热回收技术;提出了用LED技术代替现有节能灯的方案.改造后的能耗分析结果显示,提出的节能设计方案针对性强,对夏热冬冷地区公共建筑节能有着巨大的推动作用,并进一步强调了节能理念的重要性.     

When downtime is a disaster [CHP for Internet service providers]

As Internet traffic grows and more business is done on-line, many service providers and large companies are turning to third parties who can house their mission-critical servers in specialised facilities with secure power supplies, computer grade air conditioning and adequate protection against fire and intruders. One company, 186k Ltd, has opted for packaged combined cooling and power (CCP) plant at two of its telehouses. It has signed contract with Lattice Energy Services (LES), which will finance, own and operate the plant under the 20-year agreement, and provide electricity and cooling to 186k with suitable guarantees of performance and reliability. The primary energy source at both sites is the CCP system, sized to meet peak demand even with one engine on standby. This n+1 configuration means that planned maintenance and minor breakdowns can be accommodated without resorting to the back-up supply. This combined heat and power technology provides secure, cost-effective electricity and air conditioning for the telehouses     

新型全新风"免疫"空调系统的初步研究

提出了一种新型的,基于高效换热和间接蒸发冷却的全新风免疫空调系统,从理论和热力计算等方面对全新风系统和回风系统做了比较。初步研究结果表明,该新型全新风系统不但可以从根本上改善室内空气品质,而且其能量消耗水平与现有回风空调系统相接近,具有良好的研究开发前景。     

直流电机励磁与风机优化控制的研究与应用

由于非调速系统的直流电机背包风机及直流电机励磁控制在设计上存在缺陷,在轧机换辊及处理断带故障期间,背包冷却风机及直流电机励磁回路仍然正常运行,造成了大量的电能浪费,增加了吨钢电耗,制约了冷轧效益的提高。