In this paper we propose the optimization of the programming operation scheme of Silicon nanocrystal (Si-nc) memories in order to reduce the energy consumption for low power applications. Using the program kinetic characteristics and a dynamic current measurement method, the programming window and the energy consumption during Channel Hot Electrons programming are deeply analyzed; evaluating ramp and box pulse with various gate and drain voltage biases. Finally the critical role of the tunnel oxide is evaluated to satisfy both retention and consumption requirements.