Decarbonization Potential by Combining Slow Steaming and Wind-Assisted Propulsion Systems: A Case Study of a 6,500 DWT Tanker Operating in Indonesian Waters

This study addresses the growing environmental concerns of climate change, which is exacerbated by rising greenhouse gas emissions, particularly in the transportation sector. Maritime shipping, responsible for approximately 2.89% of global CO₂ emissions, is a key contributor to this issue. The International Maritime Organization (IMO) has set ambitious targets to reduce CO₂ emissions from this sector by 40% by 2030 and 100% by 2050, relative to 2008 levels. In response, this study explores the potential of combining two decarbonization strategies, slow steaming and wind-assisted propulsion systems (WAPS), to reduce emissions from maritime transport. The analysis of a 6500-ton DWT tanker operating around Sumatra Island, Indonesia, from July 21, 2023, to July 20, 2024, shows that slow steaming, reducing speed by up to 1 knot, can lead to up to a 20.1% reduction in fuel consumption and carbon emissions, although this results in increased sailing time. The challenge lies in balancing environmental benefits with operational time efficiency. The integration of WAPS, featuring three 250 m² square wingsails, further reduces emissions by 10.3% by harnessing wind power to assist propulsion, without altering the ship’s schedule. By combining both strategies, the tanker achieves a total emissions reduction of up to 29.7%, while maintaining operational efficiency. This combined approach offers a promising, sustainable solution for decarbonizing maritime transport and significantly reducing emissions without disrupting time-sensitive operations.