Achieving European climate neutrality by 2050 requires further efforts not only from the industry and society, but also from policymakers. The use of high-efficiency cogeneration facilities will help to reduce both primary energy consumption and CO₂ emissions because of the increase in overall efficiency. Fuel cell-based cogeneration technologies are relevant solutions to these points for small- and microscale units. In this research, an innovative and new fuel cell-based cogeneration plant is studied, and its performance is compared with other cogeneration technologies to evaluate the potential reduction degree in energy consumption and CO₂ emissions. Four energy consumption profile datasets have been generated from real consumption data of different dwellings located in the Mediterranean coast of Spain to perform numerical simulations in different energy scenarios according to the fuel used in the cogeneration. Results show that the fuel cell-based cogeneration systems reduce primary energy consumption and CO₂ emissions in buildings, to a degree that depends on the heat-to-power ratio of the consumer. Primary energy consumption varies from 40% to 90% of the original primary energy consumption, when hydrogen is produced from natural gas reforming process, and from 5% to 40% of the original primary energy consumption if the cogeneration is fueled with hydrogen obtained from renewable energy sources. Similar reduction degrees are achieved in CO₂ emissions.

This article presents the design and manufacturing of a hydrogen-powered unmanned aquatic surface vehicle (USV) hull. The design process comprised three stages: (1) defining the requirements for a preliminary geometry, (2) verifying the hydrodynamic hull performance using computational fluid dynamics (CFD) simulations, and (3) experimentally validating the hydrodynamic hull performance and CFD analysis results through experimental fluid dynamics in a calm water towing tank. The manufacturing process utilized additive manufacturing technologies, such as fused granular fabrication and selective laser sintering, to produce the hull and other components, including the propeller and the rudder; thermoplastic materials with carbon fiber reinforcement were employed. The experimental results demonstrate that the optimized trimaran hull exhibited low hydrodynamic resistance (7.5 N), high stability, and a smooth flow around the hull (up to 2 m/s). The design and manufacturing of the USV hull met expectations from both hydrodynamic and structural perspectives, and future work was outlined to integrate a power plant, navigation system, and scientific equipment.