The Pa‑X‑ell2 project investigated the integration of methanol fuel cells and battery storage into the power systems of large passenger ships, with a particular focus on the AIDAnova. The technical work centred on developing an energy‑management framework that can monitor and control the ship’s electrical load, optimise generator utilisation, and reduce peak demand through the use of a 360 kWh battery with a 1 h⁻¹ C‑rate. Load‑profile analysis of the ship’s three 540 kW (675 kVA) generators showed that, without storage, only 7 % of the operating time could be served by a single generator, with an average generator utilisation of 59 %. When the battery was added, the share of single‑generator operation rose to 36 % and the average utilisation increased to 86 %. The need for simultaneous operation of all three generators disappeared, and the overall generator runtime dropped from 58 h to 39 h. Similar optimisation potentials were found for other load profiles, confirming the viability of a hybrid power‑train concept.
The energy‑management system relies on “out‑of‑band” communication with consumer controls. For devices that already possess intelligent controllers, the system can request reduced power draw or delayed start‑up, thereby avoiding the need for detailed process knowledge. For devices lacking such controllers, the system applies pulse‑width modulation for resistive loads or frequency‑converter control for inductive loads. This approach keeps the detailed process logic within the device’s own controller while allowing the ship‑wide system to shape overall demand. The integration of methanol fuel cells, which exhibit slower dynamic response than combustion engines, is supported by the battery, which smooths the supply and allows generators to operate closer to their optimal load points.
Risk assessment was performed through structured Failure Modes and Effects Analyses (FMEAs) conducted in expert workshops. The analyses covered the fuel‑cell rack, individual modules, and the media used in operation, ensuring that safety requirements were met before any on‑board testing. Practical safety tests were carried out during ship visits, and the results were incorporated into the design revisions.
Collaboration involved several industry and certification partners. Meyer Werft supplied shipbuilding expertise and facilitated the installation of the test system on the AIDAnova. Carnival represented the cruise operator and provided operational data. DNV contributed regulatory and certification support, while the Italian Coast Guard reviewed the safety aspects of the fuel‑cell integration. The project was coordinated under the European Union Horizon 2020 framework, with a project duration spanning from 2018 to 2020. The consortium’s objectives included delivering a comprehensive overview of the Pa‑X‑ell2 project, presenting the planned installation on the AIDAnova, summarising the development of the maritime fuel‑cell unit, addressing regulatory and approval issues, and reporting on a risk analysis performed outside the project scope. The project’s outcomes demonstrate that combining methanol fuel cells with battery storage can significantly improve generator utilisation, reduce peak demand, and enhance the overall energy efficiency of large passenger vessels.