Summary
The existing solar boat, which concluded in 2012 the first PV-powered round-the-world trip, was adapted with a range extender system based on hydrogen and fuel cell technology. The main objective was to massively increase the energy storage capacity of this zero emissions vessel, thanks to state-of-the-art technologies without significantly increasing its total weight. This project was designed and carried out in close collaboration with the international class society in charge of the complete system certification. This class society’s early involvement greatly facilitated the definition of the safety concept and the final equipment choice.All main components were installed in a hydrogen equipment container located on the solar deck of the vessel. The hydrogen system has been monitored and improved over a period of 3 years during 28’000 nautical miles of open-sea navigation. The system was last upgraded in Hong Kong at the end of 2019. The final certification was accorded at the beginning of 2020 by the DNVGL. This certification, awarded by the world’s largest classification society, represents a prestigious and valuable reference in this sector.
This operational and certified project demonstrates that hydrogen can successfully complement batteries as an energy storage solution for renewable energy systems. Systems such as this one can also be successfully deployed even in relatively low-power systems. Their compactness permits integration even with tight dimensional constraints. Among the valuable lessons learned, each subsystem interface should be carefully optimized. In this way the global system efficiency will be as close as possible to that expected based on the specifications of the individual components and subsystems.The global circumnavigation provided a demanding test environment with a large range of weather conditions, including constant humidity, salty air and significant temperature swings. Operating such a system over months has provided unique and valuable experience, which can be applied in various energy projects for a wide range of applications, not only in the marine sector.