Integrating renewable propulsion systems in sailing yachts: An interdisciplinary life-cycle assessment and sustainable energy model

Sailing yachts can achieve operationally zero-emission propulsion by integrating solar photovoltaic (PV), wind and hydrokinetic generation with battery-electric drive systems. This study applies a systems engineering modeling framework to quantify the environmental, operational-energy and techno-economic performance of a renewable-electric retrofit for a 12 m cruising monohull, evaluated against diesel and battery-electric alternatives. An ISO 14040/14044-consistent life-cycle assessment (LCA) implemented in an Excel toolchain is coupled with time-resolved energy-balance simulations and a retrofit-oriented cost model (baseline year 2025). Over the functional unit (20 years or 20,000 nautical miles), the diesel baseline produces ∼65 t CO2-eq, while the battery-electric case yields ∼28 t CO2-eq under a moderately clean grid and the renewable-electric configuration achieves ∼10–12 t CO2-eq (∼80%–85% reduction versus diesel). In both electric cases, onboard operational CO2 emissions are eliminated, while life-cycle impacts persist due to manufacturing, replacement and end-of-life processes. Energy simulations show that integrated PV, wind and hydro generation can supply >80% of combined hotel and propulsion demand under representative cruising profiles, with storage buffering variability and an energy management strategy prioritizing real-time renewable utilization. The principal constraint is prolonged motoring in low-renewable conditions: a 30 kWh usable battery provides approximately 4 h at 5–6 kn (∼2.6–3.1 m/s). Sensitivity results emphasize that life-cycle outcomes are strongly influenced by electricity carbon intensity, battery production impacts, recycling rates and renewable availability. Overall, the study provides a transparent, replicable framework for designing and evaluating renewable-electric propulsion in recreational and small-scale marine craft within the broader scope of green technologies and sustainability.