In this research, we investigate how the electric power system generation expansion plans change and improve based on the availability of Smart Grid technologies. The new model specifically considers (i) the availability of Smart Grid technologies improving the performance of the distribution system, and/or (ii) the availability of the technologies shifting the demand from peak hours to off-peak hours. Multi-objective multi-period generation expansion planning problems are solved to determine the electricity generation technology options to be added, and where in the grid they should be constructed to simultaneously minimize multiple objectives such as cost and air emissions, e.g., CO2. Unmet demand is also considered as a cost in the objective function so that the proposed approach considers the reliability of the system. The approach used here explicitly considers availability of the system components and operational dispatching decisions. Monte Carlo simulation is used to generate component availability scenarios, and then, the mixed-integer optimization problem is solved to find optimum expansion solutions considering these scenarios. (C) 2012 Elsevier Ltd. All rights reserved.