边际电价结算和发电方报价价格结算竞价机制的经济分析

在电力交易的现货和实时市场中，世界上大多数国家及我国6个电力市场试点省市均采用按照系统的边际电价(SMP)结算的竞价机制。SMP竞价机制的不完善性导致了诸如发电方投机报价和电价上升等问题。为此，美国加州和英国采用了按照发电方报价价格(PAB)结算的竞价机制。文章根据卖方市场的不同结构进行分类，买方市场依据不同的分类标准分为：需求旺和需求弱市场：需求不确定性强和需求不确定性弱市场。接着分别从市场交易量、市场效率、消费者剩余、社会福利和市场支配力几个方面对两种竞价机制进行分析比较，提出了应根据市场特点及改革的不同阶段，选择适合的竞价机制；并指出综合SMP和PAB的竞价机制具有光明的前景。

AN ECONOMIC ANALYSIS OF COMPETITION MECHANISMS FOR SYSTEM-MARGIN-PRICING AND PAY-AS-BID

At present the competition mechanism based on system-margin-pricing (SMP) is widely applied to the day- ahead and real-time electricity market in most countries of the world and to the experimental electricity markets of six provinces in China. However, some issues, such as speculative biddings from vendors, climbing price, etc., are raised due to the incompleteness of SMP mechanism. In order to solve the problems, reforms are made first in California, USA and in United Kingdom. The competition mechanism PAB is put into use. In this paper, at first the seller market and the buyer market are categorized according to their different conditions, the seller market is classified according to the different structure, while the seller market is classified as the high demand market and low demand market or the high uncertainty and low uncertainty market in the light of the different classification standards. Secondly, through the comparison of the two competition mechanisms the detailed analysis of the two mechanisms is performed with respect to the volume of transactions, the efficiency of the market, the consumer surplus, the social warfare and the market power. Then the conclusion is obtained, that is, a proper competition mechanism should be chosen according to the features of electricity market and the emphases which should be specially laid at different stage. Finally, it is pointed out that there will be good prospects for the integration of the two competition mechanisms.