Stochastic generation-expansion planning and diversification of energy transmission paths

The paper addresses a stochastic generation-expansion planning model in the interdependent operation of an electric power system (EPS) and a natural gas system (NGS). The objective of the proposed optimization model is to provide consumers with a reliable electric energy supply by proper generation-expansion planning and diversification of energy transmission paths with minimal investment and operating costs. The proposed method takes into account constraints in the EPS and NGS. The Monte Carlo simulation method is applied to consider random outages of EPS and NGS elements and inaccuracies in the long-term electric load forecasting. A scenario reduction technique is used for reducing the computational burden of a large number of planning scenarios. The EPS and NGS are presented by a direct current (DC) model and a transportation model. The optimization problem is decoupled into a master problem and a subproblem using the Benders decomposition to cope with large-scale problems. The master problem deals with the optimization of investment in new generation units and energy transmission paths. The subproblem comprises a two-level optimization with a decomposed EPS reliability check as the master problem of the subproblem, and a NGS reliability check as the final subproblem. The case studies illustrate the applications of the proposed stochastic method in a coordinated generation-expansion planning problem when considering uncertainties. (C) 2013 Elsevier B.V. All rights reserved.