Power Procurement And Sale Strategies For Electricity Retailers Under The Guarantee Mechanism Of Renewable Energy Power Absorption

At present,China is in a critical period of green energy transformation,facing the double opportunities of rapid development of clean energy represented by renewable energy and in-depth promotion of power market reform.On May 10,2019,the national development and Reform Commission and the National Energy Administration jointly issued the "notice on establishing and improving the guarantee mechanism of renewable energy power absorption",which puts forward clear requirements for renewable energy power absorption for the main bodies participating in the power market.It marks the formal implementation of absorption the guarantee mechanism centered on the weight of renewable energy absorption responsibility in China.As the focus of China’s electricity market reform,the electricity retailer is also the subject of the obligation to bear the responsibility of renewable energy power absorption.In the process of electricity trading,the electricity retailer obtains profits through the price difference between the wholesale market and the retail market,but also faces the double risk of price fluctuation and user demand fluctuation.Therefore,it is of great practical significance to study the power procurement and sale strategies of electricity retaielrs under the dual background of the renewable energy power absorption guarantee mechanism and the electricity market reform.This paper mainly focuses on the power procurement and sale strategies of electricity retailer under the guarantee mechanism of renewable energy power absorption.Starting from the theoretical basis of the renewable energy price policy,this paper introduces the internationally universal renewable portfolio standards and the supporting green certificate transaction mechanism.It compares the characteristics and development of renewable portfolio standard in typical countries,and expounds the basic framework of China’s implementation of the mechanism of renewable energy power absorption guarantee mechanism and the status quo of green certificate transactions.Then it introduces the transaction subject and transaction mode under the framework of electricity market transaction,and analyzes the risk sources of electricity retailers in the market transaction.Based on the modern portfolio theory,this paper constructs the price fluctuation model of the electricity retailer in the medium and long term contract market,photovoltaic market,spot market,option market,hydropower market,wind power market,green certificate trading market and ancillary service market,and takes the conditional value at risk(CVaR)as the risk measurement method,constructs the minimum power purchase objective optimization model of the electricity retailer under a certain risk constraint level,and solves the optimal power purchase decision of the electricity retailer.Finally,we obtained the optimization of the electricity purchase ratio of electricity retailer in the wholesale market under different confidence levels,under different market conditions and the mature period of the green certificate market,which provides the electricity retailer’s purchasing portfolio strategy in different market situations.Established an optimization model of power procurement and sale strategy with the goal of maximizing profit and minimizing risk of electricity retailer that considers user participation in demand response projects,and takes into account the load supply and demand balance constraints and the renewable energy power absorption weight constraints.It also analyzes the profit and risk loss of electricity retailer under different schemes.At last,an example is used to prove the effectiveness of the model.The conclusion shows that a reasonable electricity sales plan can help electricity retailers obtain more income and reduce their risk of power procurement and sale.