Photovoltaic (PV) generation is emerging as an important part of the electric energy system. Various interconnection and operation technologies are needed to accommodate the PV systems into power grid operation and control. Due to the volatility of PV power outputs, it is a challenging task to enhance the overall operational efficiency of grid interconnected PV systems. This paper presents a cross-entropy (CE) based technique to optimize the generation schedule of the grid interconnected PV systems incorporating the volatility of the PV power outputs. Numerical simulation results are presented to demonstrate the effectiveness of the proposed technique. (C) 2010 Elsevier B.V. All rights reserved.