S. Salarkheili, A. Akbari Foroud, R. Keypour,
Volume 7, Issue 4 (12-2011)
Abstract
In this paper capacity withholding in an oligopolistic electricity market that all Generation Companies (GenCos) bid in a Cournot model is analyzed and the capacity withheld index, the capacity distortion index and the price distortion index are obtained and formulated. Then a new index, Distortion-Withheld Index (DWI), is proposed in order to measure the potential ability of market for capacity withholding. In these indices the impact of demand elasticity on capacity withholding is considered and it is shown that demand elasticity plays an important role for capacity withholding and market power mitigation. Due to the significant role of forward contracts for market power mitigation and risk hedging in power markets, the impacts of these contracts on capacity withholding are considered. The effects of GenCos’ strategic forward contracts on capacity withholding are also discussed. Moreover, the relationship between capacity withholding of GenCos and market price distortion is acquired. A two-settlement market including a forward market and a spot market is used to describe GenCos’ strategic forward contracting and spot market competition.
H. Bakhshandeh, A. Akbari Foroud,
Volume 12, Issue 1 (3-2016)
Abstract
This paper addresses the possibility of capacity withholding by energy producers, who seek to increase the market price and their own profits. The energy market is simulated as an iterative game, where each state game corresponds to an hourly energy auction with uniform pricing mechanism. The producers are modeled as agents that interact with their environment through reinforcement learning (RL) algorithm. Each producer submits step-wise offer curves, which include the quantity-price pairs, to independent system operator (ISO) under incomplete information. An experimental change is employed in the producer's profit maximization model that causes the iterative algorithm converge to a withholding bidding value. The producer can withhold the energy of his own generating unit in a continuous range of its available capacity. The RL relation is developed to prevent from becoming invalid in certain situations. The results on a small test system demonstrate the emergence of the capacity withholding by the producers and its effect on the market price.
