We propose a decision support method in embodiment design, dedicated to embedded autonomous microsystems design. The main objective of our work is to go beyond battery configurations by supporting the design of autonomous microsystems, namely systems able to harvest and use available energy from their environment. The main challenge of our approach consists of supporting the designer’s decisions from qualitative representation to physical models. We have thus developed instruments, both based on flows and effect analysis and behavioral component modeling. The method decreases the number of potential alternatives to obtain the best solution and the associated models. To validate our method, we focus on a marketed wired road sensor.