Optimizing Port Arrivals Could Cut Ship Emissions by Up to 25%

A recent study conducted by UCL and UMAS analyzed ship movements from 2018-2022 and revealed that optimizing port arrivals to account for port congestion or waiting times could potentially reduce voyage emissions by up to 25% for certain types of vessels. The study found that container ships and dry bulkers could see an average emissions saving of around 10%, while gas carriers and oil tankers could see savings of 16%, and chemical tankers could see savings of nearly 25%. These vessels spend between 4-6% of their operational time waiting at anchor outside ports before being granted a berth.

Chemical tankers, gas tankers, and bulk carriers experienced increasing waiting times at anchor before berthing, reaching 5.5-6% of their time per year by 2022. On the other hand, waiting times for oil tankers and container ships remained relatively constant at around 4.5% and 5.5%, respectively. The study also noted that smaller vessels generally experience longer waiting times, with operational inefficiency cited as a key factor contributing to increased emissions during this period.

The study highlighted common operational practices such as “first-come, first-served” scheduling and the “sail-fast-then-wait” approach as contributing to waiting times, along with systemic issues like port congestion, data standardization challenges, inflexible charterparties, and limited coordination among stakeholders. The Carbon Intensity Indicator (CII) regulation was also discussed, emphasizing the need to consider all aspects of the voyage to incentivize stakeholders to collaborate on reducing GHG emissions across the value chain.

Dr. Haydn Francis, a Consultant at UMAS, emphasized the importance of addressing emissions associated with port waiting times as part of broader efforts to improve operational efficiency in the shipping sector. The study also touched on the impact of port congestion on system-wide inefficiencies and its implications for low-income member states striving to decarbonize. These findings suggest potential links between enhancing system efficiencies at the ship-port interface and promoting a just and equitable transition, key considerations for mid-term measures in emissions reduction efforts.

Source