Do we need a power exchange if there are enough power marketers

Decentralization in electricity restructuring is a growing trend that Power Marketers are ex- pected to take advantage of. We consider a market composed of Power Marketers, an Indepen- dent System Operator, generators and retailers. Power Marketers behave a` la Cournot-Nash and the ISO implements a Transmission Capacity Reservation market a` la FERC. Retailers are price taker. Generators’ behavior is only reflected in the purchase costs of the Power Marketers. Their behavior is thus not really modeled. We define equilibrium of this market and show that it is efficient when the number of the Power Marketers is large enough.