电力相关市场及其集中度指标评定

RELEVANT MARKETS AND CONCENTRATION MEASURES IN ELECTRICITY WHOLESALE MARKETS

市场份额和集中度指标 HHI常用来衡量卖方的横向市场势力。然而 ,在输电容量有限的电力市场中 ,发电厂商还可能具有“位置性市场势力”,它与厂商出力的份额没有直接联系。为此 ,首先发展和引入经济学中“相关地理市场”的概念 ,在负荷侧定义“电力相关市场”;同时 ,将潮流 /交易解耦作为输电定价的一部分计入寡头市场建模和仿真 ,求解发电厂商在电力相关市场中均衡的电力销售量 ;进而 ,对各电力相关市场评定厂商销售量的占有率及其集中度指标 HHI,用这些量的加权平均作为新的市场势力指标。最后给出了一个双寡头电力库市场算例 ,结果表明新指标能综合发电厂商的横向市场势力和位置性市场势力。

Market shares and the concentration index of HHI are commonly used for measuring the horizontal market power of sellers. In power markets with constrained transmission capacities, however, generators may also have locational market power, which has no direct relation with their output shares. In this view, the paper first develops the economic concept of relevant geographic market, and defines relevant electricity markets (REMs) from the perspective of load nodes. Meanwhile, flow tracing and transaction decomposition are included as components of transmission pricing in oligopoly modeling to evaluate equilibrium sales of the generators in each REM. Sales shares and sales HHIs of the generators in the REMs are then calculated and averaged as new market power indices. A duopoly pool market is examined at the end as a numerical example. The calculation results show that the new indices can reflect both the horizontal and the locational market power of the generators.