Life Cycle Assessment (LCA) of a polyethylene recreational electric boat

Small recreational and pedal boats have been made of Glass Reinforced Plastic (GRP) for many years, reflecting the commercial advantages of this material in terms of ease of production and cost. However, the impossibility of economically recycling this material has increasingly become a problem in recent years, when the interest in a more circular vision of the industrial products is becoming more widespread among European countries. In this study, the environmental impact was evaluated over the life cycle of a small electric boat (GOGO6) with hull and covers made of High Density Polyethylene (HDPE) , designed and manufactured by the company GardaSolar S.r.l with the aim of producing an almost fully recyclable boat. At first, a comparison was made between the results of a Life Cycle Assessment of one GardaSolar boat and the model of a similar boat made of GRP, considering the same end-of-life scenario for both of them in order to highlight the environmental advantages of the polyethylene solution even in the production and utilization phases of the boat. Then, two future scenarios featuring different recycled HDPE shares (50% and 80%) were analyzed to compare their life cycle environmental impact against each other and against the current baseline. The Life Cycle Impact Assessment reveals that the electrical propulsion system represents the dominant environmental hotspot for all the scenarios, contributing between 77.8% and 99.7% of the total lifecycle impacts across every impact category and scenario, and flattening the differences resulting from hull material selection. However, when isolating the production and end of life stages of the hull and covers, the scenario with the highest share of recycled HDPE (80%) emerges as the best-performing one, whereas the GRP boat presents the highest overall environmental impacts, dominating by a wide margin in four out of the six impact categories considered (Ecotoxicity – freshwater, Eutrophication – freshwater, Human toxicity – non carcinogenic, Resource use – minerals and metals). Regarding the other two categories, the 50% recycled HDPE scenario generates the highest impact in Climate change, while the 100% virgin HDPE baseline has the highest footprint in Resource use – fossils. In conclusion, this study highlights that, although the overall impact is dominated by the electric propulsion system, HDPE emerges as a far more environmentally sustainable hull material than GRP.