As competition is introduced into the electric power industry, access and pricing policy for transmission will play a pivotal role in shaping future market structure and performance. The externalities associated with the loop flow phenomenon in an electric power network constitute a significant barrier to the formation of efficient markets for electricity and transmission services. In this paper, we present a new approach to the design of an efficient market mechanism for transmission access that resolves these externalities. Under a trading rule that combines the Coasian and the Pigouvian principles to resolution of externalities, property rights are defined so that a competitive market could be established for transmission services and electricity to achieve a social optimum within a power pool. We characterize a dynamic trading process which is Lyapunov stable and always converges to a competitive equilibrium. Finally, we discuss some practical applicability and long-term investment issues.
