不确定需求、垂直协调与电力市场结构

Demand Uncertainty, Vertical Coordination and Electricity Market Structure

本文考虑一个在发电和零售环节均为完全竞争的电力市场。电力以事先确定的线性价格销售给用户,而电力总需求不确定。模型表明,如果企业的发电量与边际发电成本之间的协方差为正,即两个随机变量之间有正的线性关联度,那么在短期均衡中,垂直分离导致较高的电力价格和发电企业利润。在长期均衡中,垂直分离导致发电企业的过度进入,形成较高的电价和较低的社会福利水平。本文的结论对我国正在进行的电力体制改革有一定参考意义。

This paper considers a perfectly competitive electricity market. Electricity is sold to consumers via predetermined linear prices. The aggregate demand is uncertain. The case where generators directly sell to consumers （vertical integration） and the case where generators sell through independent retailers （vertical separation） are discussed. It is found that when the covariance between the electricity output and the marginal generation cost is positive, vertical separation leads to higher price to consumers and higher profits to generators in the short run. In the long run, vertical separation induces excess entry to the generation sector. It leads to higher electricity price and lower social surplus. The paper thus suggests that governments should encourage vertical integration between generation and retailing in electricity markets.