Computational Aspects of Market-Clearing Mechanisms in Deregulated Power Industry

We consider combinatorial problems associated with contract satisfaction and market clearing arising in deregulated electrical power industry. A prototypical problem in this context can be stated as follows: Given a network and a (multi-)set of pairs of vertices in it denoting bilateral contracts, find the maximum number of simultaneously satisfiable contracts. The extension of the above problem to Poolco-type contract satisfaction problems is considered. Such problems also arise in real-time Internet services (e.g., telephone, fax, video). We show that these problems come in a few variants, some efficiently solvable and many NP-hard; we also present approximation algorithms for many of the NP-hard variants presented. Some of our approximation algorithms benefit from certain improved tail estimates that we derive; the latter also yield improved approximations for a family of packing integer programs.