Research On The Electricity Price Mechanism And Operation Modes Of The Photovoltaic-Battery Energy Storage System Based Power Plants

The photovoltaic-battery energy storage system(PV-BES)based power plant refers to the photovoltaic power plant equipped with battery energy storage system.The BESS can suppress the fluctuation of photovoltaic power generation,improve power quality,which is conducive to the improvement of the capacity of the power grid to accept large-scale photovoltaic power generation and promote photovoltaic energy consumption.While the PV-BESS power plant in China is still in the initial stage of development,and the investment cost of battery energy storage system is high.Under the existing PV grid tariff mechanism and operation mode,a PV-BESS power plant is difficult to get reasonable economic benefits to make up for the investment cost of BESS.Therefore,it is of important theoretical and practical value for promoting the promotion and construction of the PV-BESS power plant to establish a reasonable on-grid electricity price mechanism and operation modes considering the characteristics of construction and operation.Based on the seasonal characteristics and timing characteristics of photovoltaic power generation,the Self Organizing Maps(SOM)clustering method is applied to analyze the generating curves of the PV-BESS power plant,and establish the typical operation scenarios.Then the operation mode based on the typical scenarios is established considering the power generation revenue,assessing rewards/penalties as well as peak shaving/valley filling revenue.And the revenue of the PV-BESS power plant under this operation mode is compared with that under the existing operation mode.The case studies show that,compared with the existing operation mode,the operation mode based on the typical scenarios can make the PV-BESS power plant get better economic benefits,and provide guidance for the operation of the PV-BESS power plant under the existing PV tariff.A three-part electricity price mechanism is proposed based on a deep analysis of the construction and operation costs and economic income.The on-grid electricity price is divided into three parts: the capacity price,graded electricity price,and ancillary service price.To ensure that the investment of the PV-BESS power plant would achieve the industry benchmark income,the capacity price and benchmark electricity price are calculated using the discounted cash flow method.The graded electricity price is calculated according to the grade of the quality of grid-connected power.The ancillary service price is calculated based on the graded electricity price and ancillary service compensation.The case studies show that compared with the existing PV benchmark electricity price,the three-part electricity price mechanism can make the PV-BESS power plant obtain reasonable economic benefits,shorten the investment recovery period and increase the internal rate of return of investment.Combine the three-part electricity price considering the power quality and ancillary services with the typical operation scenarios of the PV-BESS power plant,the operation mode based on three-part electricity price and typical scenarios is established.The revenue of the PV-BESS power plant under this mode is compared with that under the operation mode based on the typical scene and under the existing operation mode.The case studies show that the operation mode based on the three-part electricity price and typical scenario can further improve the economic benefits of the PV-BESS power plant,which can promote the promotion of the PV-BESS power plant.