An increasing presence of renewable energy forms, due to environmental and socio-economic reasons, in the electric power industry necessitates an assessment of the impact of these sources, on a conventional electric utility. This assessment incorporates stochastic theory to investigate the security and stability of a wind energy conversion system on an electrical utility to quantify the limits of such a system's operation. This paper presents a model that captures the uncertainties in the system load at the wind generator bus, a method that approximates the randomness experienced by the system. Future dynamic models in development will capture noise due to wind effects. A simple model of a grid-connected WECS is presented. An index of reliability is also determined known as the mean first passage time (MFPT), the time taken for the system to leave its stability region.