The ever-growing interest toward energy efficiency imposes the optimization of mechanism design under an energetic point of view. Even if the benefit of using spring balancing systems to reduce energy consumption is intuitive, the relation between spring design and electrical energy consumption has never been systematically addressed in the literature, which is mainly focused on static compensation of gravity forces. This paper tackles this novel and important issue and proposes an analytical method for model-based design of springs minimizing the energy required in rest-to-rest motion. The method relies on the model of energy dissipation that accounts for the characteristics of the mechanical, electrical, and power electronic components of a servo-actuated mechanism. The theory is developed with reference to a single rotating beam. The proposed solution ensures significant energy saving compared with the traditional static balancing design of springs and is particularly suitable for repetitive (cyclic) motion tasks.