This workshop will focus on mathematical modeling and solution techniques for large scale problems in electric power system planning under uncertainty. Because of the uncertainties concerning future costs, demands for electricity, and availabilities of generation and transmission facilities, such planning models must take the form of multiperiod, stochastic mathematical (linear or nonlinear) programs. Various avenues of research being done in various places to tackle this problem is the subject of this workshop. The workshop proceedings will be sent out to the broader research community to stimulate further research in this area.