Power Procurement And Sale Strategies For Electricity Retailers Under Renewable Portfolio Standards

In order to alleviate the shortage of energy supply and the environmental pollution caused by fossil fuels,governments have launched a series of incentive policies to promote the development of renewable energy.Renewable portfolio standards(RPS)can allocate the target of renewable energy consumption to specific obligatory subjects,which is one of the important means to achieve the national total amount target.Moreover,it can use green certificate trading market mechanism to effectively reduce the cost of renewable energy generation and promote the progress of green energy technology.Based on the international advanced experience and actual situation in China,the framework and power market system for the RPS implemented in the power demand side in China are constructed.On this basis,the optimization of power procurement and sale strategy for electricity retailers under RPS requirements is studied.Based on the summary of the existing RPS implemented in the power demand side in developed countries,the necessity and feasibility of implementing this system in China are analyzed,and the basic framework of RPS in demand side is constructed.Four key indices including the obligation subject,the renewable power target form,the qualified renewable energy types and the green certificate market participants are designed innovatively.At the same time,a new power market structure considering renewable energy contract market and green certificate spot market is constructed,and new behavior strategies and trading modes adopted by different market participants under renewable energy quota requirements are studied.Based on the influence of RPS on the structure of power market and decision-making of electricity retailers' power procurement,in order to meet the dual requirements of power and quota,how to match the appropriate purchase proportion in four markets including conventional power contract market,spot power market,renewable energy contract market and green certificate spot market is discussed.CVaR risk measurement index is introduced to establish a decision-making model of power purchasing for retailers considering the expectation of power purchasing cost-CVaR risk under the restriction of RPS.The strategies of power purchasing under different development stages and different confidence levels are obtained through the model,which can provide new ideas,methods and basis for the optimization of long-term electricity purchasing ratio for the retailers.Considering the guiding role of peak and valley time-of-use tariff on users' demand for electricity,an optimization model of marketing strategy for electricity retailers is proposed,which takes account of demand-side response.By introducing peak-valley electricity price selling business,the customer demand response model under peak and valley based on the price elasticity matrix is established.On this basis,an optimization model of marketing strategy for electricity retailers is constructed,which aims at maximizing the comprehensive utility of power purchasing and selling revenue and CVAR risk under the restriction of RPS.The rationality of setting peak and valley time-of-use price and the effectiveness of improving the revenue as well as reducing the risk of power purchase and sale decision are verified by an example.