In this paper, a linear generator for a highly reliable wave energy conversion system is designed and tested. In order to store energy, the system is able to produce hydrogen. The wave energy conversion system consists of an electrical linear generator, a power conversion system, and a sea-water electrolyzer. A small-scale prototype of the system is designed and built. The design is oriented to the enhancement of the system robustness and reliability and a failure mode and effects and criticality analysis are used. In order to guarantee an easy extension of the power capability of the marine plant, a modular architecture of the system is adopted. The design strategy is described. The robustness and reliability of the proposed solution are discussed. Simulation and experimental results on the prototype are shown.