The ENGIMMONIA project successfully achieved its objectives, delivering a coherent set of technological, environmental and regulatory results that advance the decarbonisation of long‑distance maritime transport. The project demonstrated that ammonia is a technically feasible and promising alternative marine fuel, validated through extensive laboratory and full‑scale engine testing. Stable combustion was achieved in dual‑fuel configurations, with low ammonia slip, controlled NOx emissions and consistently low nitrous oxide (N2O) levels. These results confirm ammonia’s strong potential to reduce greenhouse gas emissions, particularly with the future availability of green ammonia.
In parallel, ENGIMMONIA developed and validated complementary clean energy technologies, including compact Organic Rankine Cycle (ORC) systems for waste heat recovery, adsorption chillers, lightweight photovoltaic composite panels and advanced onboard energy management systems. These solutions were successfully designed, integrated and demonstrated on different vessel types, showing measurable energy savings and emission reduction potential. The results highlighted that technical effectiveness and economic viability depend strongly on vessel type, size and operational profile, with larger vessels offering higher decarbonisation potential due to greater energy demand and waste heat availability.
The project also delivered advanced modelling tools, life‑cycle cost and environmental assessments, and scale‑up analyses, demonstrating that integrated configurations combining multiple technologies provide the greatest benefits. From a regulatory perspective, ENGIMMONIA generated valuable evidence to support the development of international guidelines for ammonia as a marine fuel, while identifying remaining gaps related to safety standards, bunkering infrastructure and detailed regulatory provisions. From a market perspective, ENGIMMONIA highlighted that technical readiness alone is insufficient to enable uptake. Clear value propositions must be demonstrated to shipowners, linking fuel savings, emission reductions and operational reliability to specific vessel segments. Early involvement of end users proved essential to align technology design with real operational constraints, particularly regarding space, retrofit complexity and maintenance requirements. Market deployment should prioritise vessels and routes where benefits are most tangible, enabling first commercial references. Finally, confidence building through full‑scale demonstrations, transparent performance data and standardised solutions emerged as a key lesson to reduce perceived risk and accelerate the transition from pilot applications to bankable commercial offerings.
