This paper presents a new method for optimizing the layout position of an Industrial Robot (IR) in order to execute a specified task with the minimum energy consumption. First, using the Modelica language, an IR mechatronic model is developed, focusing on computational efficiency: addressing the power flow from the electrical network, the sub-system components are modeled with the level of detail strictly necessary for an accurate prediction of the power consumption, while assuring efficient computational efforts. Once a robot task is assigned, the optimal layout IR position is calculated using optimization techniques that retrieve the robot base position corresponding to the minimum energy consumption. Additionally, the designer can optimize the overall robotic work cell with the aid of a set of colour/contour maps that depict the energy demand along with the time required for the task completion. Development, simulation and optimization phases are performed in Dymola environment.