2010年抽水蓄能电站在华东电网合理规模探讨

根据华东电网电源现状与负荷特性预测,在比较电力系统调峰措施方案的基础上,通过电力电量平衡及调峰容量盈亏分析,论述了华东电网加快建设抽水蓄能电站的必要性;运用电源优化规划模型,对华东电网所需抽水蓄能电站的合理规模进行了分析,提出了2010年华东电网新增抽水蓄能电站装机容量占华东统调电网的合理比例,为华东地区电力系统电力规划提供了参考.     

基于电锅炉的火电机组灵活性改造技术研究

为有效解决东北电力产能过剩,促进风电、核电等清洁能源消纳问题,提升燃煤供热机组的灵活性,针对东北地区某热电厂,通过对热电解耦时间、电锅炉型式以及不同电锅炉容量配置对机组实际发电负荷的影响等灵活性改造关键技术进行研究,确定了最佳电锅炉容量,提出了电锅炉装设方案,并对改造前后机组的调峰能力和性能指标进行对比分析。研究表明:随着电锅炉容量增长,抵减电锅炉用电后机组实际发电负荷率显著降低,提升火电机组灵活性改造后,电厂调峰能力显著提升,考虑以全厂172 MW发电负荷运行,电厂调峰能力在采暖初末期增加了368 MW,采暖中期增加了528 MW;全厂供热标煤耗由39.7 kg/GJ降低至34.3 kg/GJ,降低了5.4 kg/GJ;经济效益显著,扣除电锅炉用电成本后1个采暖季的调峰辅助服务补贴收益为1.47亿元;同时,电锅炉投运后可实现电厂的上网电量接近零,为清洁能源就地消纳做出贡献。     

仙居抽水蓄能电站建设必要性和经济性分析

华东电网(江苏、浙江、安徽、上海)是我国最大的跨省市电网，地区经济发展处于我国的先进水平，电力需求增长迅猛，而区内能源资源缺乏，可开发水电资源已经不多，系统将重点发展大容量、高参数煤电机组．积极发展天然气、LNG和核电，还将接受大量区外来电。区内供需矛盾较为突出，调峰压力将进一步增大。为缓解系统调峰压力、优化电源结构、改善系统安全、经济、稳定运行条件，建设一定规模的抽水蓄能电站是必要的。仙居抽水蓄能电站地理位置适中，建设条件优越，经济指标优良，接入系统方便，通过经济分析，仙居抽水蓄能电站是一个经济的调峰备用电源。电站建成后可服务于华东电网和浙江电网。     

天然气联合循环电厂燃烧后CO2捕集一体化技术经济评价

  目的  近年来,天然气发电在我国构建清洁能源体系中扮演着重要角色,预计到2025年“十四五”规划期结束时,中国气电装机容量将会突破150 GW。二氧化碳捕集利用是气电实现“双碳”目标的关键路径之一。  方法  为此,设立1个600 MW等级天然气联合循环发电（NGCC）、1个CO₂捕集和压缩（PCC）的综合工厂作为模拟对象。  结果  模拟研究表明:设计CO₂全烟气量捕集、90%效率、CO₂压缩提纯率为99.5%,燃气发电总出力输出下降了约16.05%,厂用电率增加5.55%,循环冷却水需求增加了约50.52%。  结论  通过经济分析显示,综合工厂的静态投资成本比单一发电厂的成本高54.28%,电力均等化运营成本（LCOE）增加了15.96%,给二氧化碳捕集的部署和发展带来了非常大的困难。但其中天然气价格仍然是影响电厂运营成本的最主要因素。     

筹建小型抽水蓄能电站提高电网供电质量

西北电网虽然水电装机比重较大，调峰矛盾比其它电网较为缓和，但仍需筹建小型抽水蓄能电站，以提高电网供电质量。翠华山天池是条件较好的蓄能电站坝址，可为系统提供３２０ＭＷ调峰容量。     

Shaping the future of global energy delivery

Globally, the increasing power demand is coupled with environmental constraints and strong competition that require advanced solutions for global power transmission. System reliability and congestion relief are imperative under dynamic market conditions to ensure that transmission systems provide a steady return on investment and cash flow as well as operate with the flexibility and security that will be required to serve future demand and load growth. Given all of the factors that must be balanced, the one certainty is that new technology will be a key enabler to move transmission investment forward and increase capacity. A few of the innovations that have the potential to shape the future of the global power system are already available or will soon be commercially available. Some, but definitely not all, of these new technologies are briefly discussed in this article including flexible AC transmission system (FACTS), HVDC transmission, short current limiters, overhead lines, gas insulated transmission lines, gas insulated switchgear, and grid connected wind generation.     

Time-averaging period for regulation service

Because electricity is a real-time product, power system operators must adjust generation to match load on a moment-to-moment basis, providing the ancillary service called regulation. But what is meant by moment-to-moment? This article addresses that question by providing background information on the regulation ancillary service and by analyzing short-interval changes in system-level generation and load for four electrical systems. Three systems are large, with peak demands between 10,000 and 20,000 MW, while the fourth system has a peak demand of under 5,000 MW. One of the large systems relies primarily on hydro units for regulation, while the other three systems use fossil units. For each system, the authors obtained 30-second data for 1 or more days on total generation and load. They analyzed these data to see how quickly and with how much lag generation follows load     

Large-scale hydrogen energy storage in salt caverns

Large-scale energy storage methods can be used to meet energy demand fluctuations and to integrate electricity generation from intermittent renewable wind and solar energy farms into power grids. Pumped hydropower energy storage method is significantly used for grid electricity storage requirements. Alternatives are underground storage of compressed air and hydrogen gas in suitable geological formations. Underground storage of natural gas is widely used to meet both base and peak load demands of gas grids. Salt caverns for natural gas storage can also be suitable for underground compressed hydrogen gas energy storage. In this paper, large quantities underground gas storage methods and design aspects of salt caverns are investigated. A pre-evaluation is made for a salt cavern gas storage field in Turkey. It is concluded that a system of solar-hydrogen and natural gas can be utilised to meet future large-scale energy storage requirements.     

Statistical analysis of negative prices in European balancing markets

The presence of renewable power generation technologies increases the need for system flexibility due to their variable nature. The increasing share of variable renewables in European power systems create a downward adequacy problem, which deals with the ability of power systems to cope with periods of excess generation. The occurrence of negative prices on Central Western European electricity markets confirms the relevance of this issue, which is referred to as “incompressibility of power systems” and is assessed as a barrier for further renewable power integration. The objective of this article is to identify the main drivers of negative price periods in European balancing markets, by means of both an empirical and regression analysis. Results confirm a positive relation with the scheduled generation of renewables and inflexible base load, as well as a negative relation with the scheduled system load. Furthermore, the occurrence of negative prices is related to the positive and negative forecast error of renewable generation and demand, respectively. It is concluded that negative balancing market prices provide a market signal for investments in flexibility sources such as flexible generation, demand response, electricity storage, and interconnector capacity.     

Economics of compressed air energy storage to integrate wind power: A case study in ERCOT

Compressed air energy storage (CAES) could be paired with a wind farm to provide firm, dispatchable baseload power, or serve as a peaking plant and capture upswings in electricity prices. We present a firm-level engineering-economic analysis of a wind/CAES system with a wind farm in central Texas, load in either Dallas or Houston, and a CAES plant whose location is profit-optimized. With 2008 hourly prices and load in Houston, the economically optimal CAES expander capacity is unrealistically large – 24 GW – and dispatches for only a few hours per week when prices are highest; a price cap and capacity payment likewise results in a large (17 GW) profit-maximizing CAES expander. Under all other scenarios considered the CAES plant is unprofitable. Using 2008 data, a baseload wind/CAES system is less profitable than a natural gas combined cycle (NGCC) plant at carbon prices less than $56/tCO₂ ($15/MMBTU gas) to $230/tCO₂ ($5/MMBTU gas). Entering regulation markets raises profit only slightly. Social benefits of CAES paired with wind include avoided construction of new generation capacity, improved air quality during peak times, and increased economic surplus, but may not outweigh the private cost of the CAES system nor justify a subsidy.     

海南省天然气发电竞争力分析

天然气发电有利于优化我国能源结构,对我国天然气市场发展具有重要的支撑作用,对改善电力供应结构和提高电网的安全性具有重要意义。本文分析了海南省发展天然气发电与天然气分布式能源的环境的支撑关系,并剖析天然气发电对海南省建立低碳经济、改善能源供应结构和用电调峰等方面的积极作用。     

Dynamic modeling,design and simulation of a wind/fuel cell/ultra-capacitor-based hybrid power generation system

Recent research and development of alternative energy sources have shown excellent potential as a form of contribution to conventional power generation systems. In order to meet sustained load demands during varying natural conditions, different energy sources and converters need to be integrated with each other for extended usage of alternative energy. The paper focuses on the combination of wind, fuel cell (FC) and ultra-capacitor (UC) systems for sustained power generation. As the wind turbine output power varies with the wind speed: an FC system with a UC bank can be integrated with the wind turbine to ensure that the system performs under all conditions. We propose herein a dynamic model, design and simulation of a wind/FC/UC hybrid power generation system with power flow controllers. In the proposed system, when the wind speed is sufficient, the wind turbine can meet the load demand while feeding the electrolyzer. If the available power from the wind turbine cannot satisfy the load demand, the FC system can meet the excess power demand, while the UC can meet the load demand above the maximum power available from the FC system for short durations. Furthermore, this system can tolerate the rapid changes in wind speed and suppress the effects of these fluctuations on the equipment side voltage in a novel topology.     

A novel method to investigate voltage stability of IEEE-14 bus wind integrated system using PSAT

The maximum demand of power utilization is increasing exponentially from base load to peak load in day to day life. This power demand may be either industrial usage or household applications. To meet this high maximum power demand by the consumer, one of the options is the integration of renewable energy resources with conventional power generation methods. In the present scenario, wind energy system is one of the methods to generate power in connection with the conventional power systems. When the load on the conventional grid system increases, various bus voltages of the system tend to decrease, causing serious voltage drop or voltage instability within the system. In view of this, identification of weak buses within the system has become necessary. This paper presents the line indices method to identify these weak buses, so that some corrective action may be taken to compensate for this drop in voltage. An attempt has been made to compensate these drops in voltages by integration of renewable energy systems. The wind energy system at one of the bus in the test system is integrated and the performance of the system is verified by calculating the power flow (PF) using the power system analysis tool box (PSAT) and line indices of the integrated test system. The PF and load flow results are used to calculate line indices for the IEEE-14 bus test system which is simulated on PSAT.     

A Monte Carlo approach to generator portfolio planning and carbon emissions assessments of systems with large penetrations of variable renewables

A new generator portfolio planning model is described that is capable of quantifying the carbon emissions associated with systems that include very high penetrations of variable renewables. The model combines a deterministic renewable portfolio planning module with a Monte Carlo simulation of system operation that determines the expected least-cost dispatch from each technology, the necessary reserve capacity, and the expected carbon emissions at each hour. Each system is designed to meet a maximum loss of load expectation requirement of 1 day in 10 years. The present study includes wind, centralized solar thermal, and rooftop photovoltaics, as well as hydroelectric, geothermal, and natural gas plants. The portfolios produced by the model take advantage of the aggregation of variable generators at multiple geographically disperse sites and the incorporation of meteorological and load forecasts. Results are presented from a model run of the continuous two-year period, 2005–2006 in the California ISO operating area. A low-carbon portfolio is produced for this system that is capable of achieving an 80% reduction in electric power sector carbon emissions from 2005 levels and supplying over 99% of the annual delivered load with non-carbon sources. A portfolio is also built for a projected 2050 system, which is capable of providing 96% of the delivered electricity from non-carbon sources, despite a projected doubling of the 2005 system peak load. The results suggest that further reductions in carbon emissions may be achieved with emerging technologies that can reliably provide large capacities without necessarily providing positive net annual energy generation. These technologies may include demand response, vehicle-to-grid systems, and large-scale energy storage.     

Analysis of impacts of wind integration in the Tamil Nadu grid

As the share of wind in power systems increases, it is important to assess the impact on the grid. This paper combines analysis of load and generation characteristics, generation adequacy and base and peak load variations to assess the future role of wind generation. A simulation of Tamil Nadu in India, with a high penetration of wind power (27% by installed capacity), shows a capacity credit of 22% of the installed wind capacity. For seasonal wind regimes like India, neither the capacity factor, nor the capacity credit reflects the monthly variation in the wind generation. A new approach based on the annual load duration curve has been proposed for generation expansion planning with higher penetration of wind. The potential savings in base and peak capacity required with increasing wind power have been quantified. A future scenario for Tamil Nadu for 2021 has been illustrated. It was found that 5500 MW of wind power can save 3200 MU of peak energy required or an average peak capacity of 2400 and 1100 MW of base capacity. This analysis would be useful to assess the future impacts of increasing wind capacity in grids.     

A scenario analysis of investment options for the Cuban power sector using the MARKAL model

The Cuban power sector faces a need for extensive investment in new generating capacity, under a large number of uncertainties regarding future conditions, including: rate of demand growth, fluctuations in fuel prices, access to imported fuel, and access to investment capital for construction of new power plants and development of fuel import infrastructure. To identify cost effective investment strategies under these uncertainties, a supply and power sector MARKAL model was assembled, following an extensive review of available data on the Cuban power system and resource potentials. Two scenarios were assessed, a business-as-usual (BAU) scenario assuming continued moderate electricity load growth and domestic fuel production growth, and a high growth (HI) scenario assuming rapid electricity demand growth, rapid increase in domestic fuel production, and a transition to market pricing of electricity. Within these two scenarios sets, sensitivity analyses were conducted on a number of variables. The implications of least-cost investment strategies for new capacity builds, investment spending requirements, electricity prices, fuel expenditures, and carbon dioxide emissions for each scenario were assessed. Natural gas was found to be the cost effective fuel for new generation across both scenarios and most sensitivity cases, suggesting that access to natural gas, through increased domestic production and LNG import, is a clear priority for further analysis in the Cuban context.     

Analysis of imperfect competition in natural gas supply contracts for electric power generation: A closed-loop approach

The supply of natural gas is generally based on contracts that are signed prior to the use of this fuel for power generation. Scarcity of natural gas in systems where a share of electricity demand is supplied with gas turbines does not necessarily imply demand rationing, because most gas turbines can still operate with diesel when natural gas is not available. However, scarcity conditions can lead to electricity price spikes, with welfare effects for consumers and generation firms. We develop a closed-loop equilibrium model to evaluate if generation firms have incentives to contract or import the socially-optimal volumes of natural gas to generate electricity. We consider a perfectly-competitive electricity market, where all firms act as price-takers in the short term, but assume that only a small number of firms own gas turbines and procure natural gas from, for instance, foreign suppliers in liquefied form. We illustrate an application of our model using a network reduction of the electric power system in Chile, considering two strategic firms that make annual decisions about natural gas imports in discrete quantities. We also assume that strategic firms compete in the electricity market with a set of competitive firms do not make strategic decisions about natural gas imports (i.e., a competitive fringe). Our results indicate that strategic firms could have incentives to sign natural gas contracts for volumes that are much lower than the socially-optimal ones, which leads to supernormal profits for these firms in the electricity market. Yet, this effect is rather sensitive to the price of natural gas. A high price of natural gas eliminates the incentives of generation firms to exercise market power through natural gas contracts.     

Building air conditioning system using fuel cell: Case study for Kuwait

Air conditioning machines in Kuwait consume more than 75% of electric energy generated at peak load time. It is in the national interest of Kuwait to decelerate the continuous increase of peak electric power demand. One way to do this is to install for new complexes or high-rise apartments buildings distributed utilities (isolated small power plants), mainly for air conditioning A/C systems. Fuel cells are among the alternatives considered for distributed utilities.This paper discusses the use of commercially available phosphoric acid fuel cell PAFC, known as ONSI P25 to operate air conditioning systems for big buildings in Kuwait.The proposed fuel cell, which is usually delivered with built-in heat exchanger for hot water, is operated by natural gas and uses a propylene glycol-water loop to recover thermal energy. The PAFC has 200 kW nominal electric power capacity, and produces thermal energy of 105 kW thermal energy at 120 °C, and 100 kW at 60 °C.The performance characteristics for the proposed fuel cell are very well documented. In the present study, it is suggested that the fuel cell operates combined mechanical vapor compression and absorption water chillers to utilize the fuel cell full output of electric power and waste heat. Also, to meet the required A/C cooling capacity system by the limited fuel cell power output, it is proposed to use cold storage technique. This allows fuel cell power output to supply the needed energy for average as well as peak A/C system capacity.     

Greenhouse gas emission intensity factors for marginal electricity generation in Canada

In Canada, each province has its own electric utility system, and each system is responsible for meeting the demand of its customer base. Electricity demand in all provinces is highly variable throughout the day, as well as during the year. In order to achieve a good match between electricity demand and generation, a mix of base, intermediate and peaking load power plants is used, which uses different fuel sources. When a renewable energy technology or an energy efficiency measure that results in electricity savings is implemented on a regional, provincial and national scale, the electricity savings reflect in the peak (marginal) electricity generation. Thus, the greenhouse gas (GHG) emission reduction due to the reduction in electricity generation corresponds to the fuel used to generate the electricity at the margin. In Canada, the fuel used for marginal electricity generation varies from province to province and from hour to hour. To estimate the reduction in GHG emissions due to reducing electricity generation at the margin, it is necessary to have information on the fuel mix used to generate the marginal electricity for each province on a suitable time scale. With such information, it is possible to estimate a marginal GHG emission intensity factor for each province, which would provide the amount of GHG emissions produced as result of producing 1 kWh of electricity on the margin. However, such information is regarded confidential by most electric utilities and is not made public. In this paper, methodologies are presented to estimate the GHG intensity factors (GHGIFs) for marginal electricity generation for each province of Canada based on the information available in the public domain. The GHGIFs developed for each province are also presented, which are expected to be valid within the next 5‐year horizon. Copyright © 2010 John Wiley & Sons, Ltd.     

Representation of variable renewable energy sources in TIMER,an aggregated energy system simulation model

The power system is expected to play an important role in climate change mitigation. Variable renewable energy (VRE) sources, such as wind and solar power, are currently showing rapid growth rates in power systems worldwide, and could also be important in future mitigation strategies. It is therefore important that the electricity sector and the integration of VRE are correctly represented in energy models. This paper presents an improved methodology for representing the electricity sector in the long-term energy simulation model TIMER using a heuristic approach to find cost optimal paths given system requirements and scenario assumptions. Regional residual load duration curves have been included to simulate curtailments, storage use, backup requirements and system load factor decline as the VRE share increases. The results show that for the USA and Western Europe at lower VRE penetration levels, backup costs form the major VRE cost markup. When solar power supplies more than 30% of the electricity demand, the costs of storage and energy curtailments become increasingly important. Storage and curtailments have less influence on wind power cost markups in these regions, as wind power supply is better correlated with electricity demand. Mitigation scenarios show an increasing VRE share in the electricity mix implying also increasing contribution of VRE for peak and mid load capacity. In the current scenarios, this can be achieved by at the same time installing less capital intensive gas fired power plants. Sensitivity analysis showed that greenhouse gas emissions from the electricity sector in the updated model are particularly sensitive to the availability of carbon capture and storage (CCS) and nuclear power and the costs of VRE.