RealHyFC gathers key actors of the whole PEMFC value chain to overcome crucial hurdles towards industrial empowerment on heavy-duty (HD) applications, mainly for land transport while expecting benefits for ships, trains or aircrafts. The technical issues precluding a rapid and wide adoption of PEMFC on HD applications are linked with reliability and versatility of the stacks. RealHyFC will bring knowledge and experimental feedback on two key levels: stack design and stack operation. Regarding stack design, carbon and metallic technologies will be investigated on efficiency and lifetime issues, local degradation and mechanical properties. Unpreceded direct comparison will be possible thanks to the adaption of an open-design made for metal to carbon-composite case, with developments on bipolar plates and balance of stack. RealHyFC will eventually deliver a public open-design platform with demonstrated high efficiency and durability under HD application conditions. For long-lasting operation, the diagnostics and monitoring of stacks are crucial to preclude damages on performance or components: RealHyFC will bring new solutions based on improved physical degradation models allowing to develop virtual sensors algorithms to optimize fuel cell operating conditions and hybridization strategy. Final validation, by demonstration of lifetime improvements thanks to an adjusted control chain, will be done following system-representative simulation and experimental approaches towards durability-oriented operation in HD environment. The outcomes of the project are strongly linked with the industrial world and settings carrying relevant PEMFC use. RealHyFC will enable the development of cost-competitive, reliable and durable fuel cell technology. To this extend, an exploitation strategy will foster industrial empowerment, alongside dissemination and communication towards technical audience and large public.