The goals for sustainable development endorsed by the United Nations include responsible management of consumption and production (Sustainable Development Goal 12). In a world relying increasingly on robotics and automation in production environments, the consumption of energy by robotic systems should be given careful consideration and study. In this paper, we examine the potential for increasing the overall efficiency of these systems through integration of passive-dynamic devices, specifically variable-stiffness mechanisms, into commonly executed robotic tasks. The intent is to achieve smoother (and thereby less energy consumptive and wear-inducing) motions during robotic tasks without computationally expensive control approaches. The simulation results presented in this paper support the validity and value of this approach and motivate additional study of the integration of variable-stiffness mechanisms with industrial robots.