电网侧电化学储能经济性分析方法

Economic Analysis of Grid-side Electrochemical Energy Storage

随着可再生能源装机规模的不断提高,储能成为保证风电、光伏等间歇性可再生能源大规模、平稳接入电网的关键技术。利用电化学储能可灵活配置、响应速度快、适合规模化应用等优势,在电网侧不仅可提供调峰、调频、电压调节、旋转备用等辅助服务,还能产生延缓设备投资、降低电网损耗、回收退役电池等间接价值。辅助服务是目前电网侧储能最直接可靠的收益来源,其中调峰收益是单位电量补偿标准与充放电电量的乘积;调频收益由储能系统接受自动发电控制调度指令的响应容量和时间,以及单次调用调频性能指标和补偿标准决定;电压调节与电站容量、投运时间、自动电压控制投运率和调节合格率有关;旋转备用收益是单位补偿标准与备用容量、备用时间的乘积。从全生命周期看,储能成本主要包括设备成本、购电成本和运维成本。结合电网侧储能价值收益和成本计算方法,提出储能经济性的简易判据,即储能系统各项收益总和以及成本总和的年化数值之差。以安徽省为例,基于华东和安徽现有储能政策,分析电网侧电化学储能的经济性,分析思路和方法在其他省区也具备适用性。

With the continuous increase in the installed capacity of renewable energy,energy storage has become the key technology to ensure the large-scale and smooth access of intermittent renewable energy such as wind power and photovoltaic to the grid.Based on the advantages such as flexible configuration,fast response and suitability for large-scale applications,electrochemical energy storage can provide not only auxiliary services such as peak shaving,frequency modulation,voltage regulation and spinning reserve on the power grid side,but also generate indirect value such as delaying equipment investment,reducing power grid losses and recycling retired batteries.Auxiliary service is the most direct and reliable source of income for grid-side energy storage.Peak shaving income is the product of unit power compensation standard and charging and discharging power.Frequency modulation income is determined by the response capacity and time of the energy storage system to receive automatic generation control dispatching instructions,as well as the single call frequency modulation performance indicators and compensation standards.Voltage regulation income is related to power station capacity,operation time,operation rate of automatic voltage control,and regulating qualification rate.Spinning reserve income is the product of unit compensation standard,reserve capacity and backup time.From the perspective of full life cycle,energy storage cost mainly includes equipment cost,electricity purchasing cost and operation and maintenance cost.Combined with the value return and cost calculation methods of grid-side energy storage,a simple criterion for energy storage economy is given,which is the difference between the annualized values of total income and total cost of energy storage system.Finally,taking Anhui Province as an example,the economic analysis of grid-side electrochemical energy storage is presented based on the current energy storage policies in East China and Anhui Province,and the analysis ideas and methods are applicable in other provinces and regions.