It is desirable that robots would be, as much as possible, autonomous and self-sufficient. This requires that they can perform their duties while maintaining enough energy to operate. On this regard this paper presents the design and initial results for the power supply of an autonomous robot. Actually Robot design is divided into four primary areas: energy storage, actuation, power and control. But of course there are many relationships among these phases so as matter of fact they have to be made in parallel to optimize the robot especially energetically. In particular a power supply solution that utilizes solar cells and a microcontroller have been chosen to power and control the robot. Finally, initial tests with a probe-loaded robot prototype have demonstrated the feasibility of the solution.