Published in: Electrical power & Energy systems

Publication year: 2007
Co-Author 1: Anni Huang

Co-Author 2: Kyung-Bin Song

This paper presents an asynchronous decentralized method to solve the optimization problem of interconnected electricity markets. The proposed method decomposes the optimization problem of combined electricity markets into individual optimization problems. The impact of neighboring markets’ information is included in the objective function of the individual market optimization problem by the standard Lagrangian relaxation method. Most decentralized optimization methods use synchronous models of communication to exchange updated market information among markets during the iterative process. In this paper, however, the solutions of the individual optimization problems are coordinated through an asynchronous communication model until they converge to the global optimal solution of combined markets. Numerical examples are presented to demonstrate the advantages of the proposed asynchronous method over the existing synchronous methods.

Published in: The Energy Journal

Publication year: 2007
Co-Author 1: Jeffrey Williams

Do natural gas storage decisions indistant California respond to NYMEX

futures price spreads? Daily data about flows into and out of storage facilities in California over 2002-2006 and daily spreads on NYMEX are used to investigate whether the net injection profile is consistent with the "supply-of-storage" curve first observed by Working for wheat. Storage decisions in California do seem to be influenced by a price signal that combines the intertemporal spread and the location at basis between California and the Henry Hub, in addition to strong seasonal and weekly cycles that determine net injections to a considerable extent. The timing and magnitude of the price response differ across storage facilities. Regulatory requirements and operational constraints also limit the response to short-lived arbitrage opportunities.