Anchoring and emissions are analyzed

A large part of ships' carbon dioxide emissions occur when spending time waiting at anchor outside ports. How can these emissions be reduced? A pre-study within the industry program Sustainable Shipping, which is run by Lighthouse, is looking for answers.

They are lying there waiting with the engines running, produceing electricity for lighting, fans, heating and cooling systems and everything else that needs to be running when a ship is at anchor.

“There are many things that play a role in how large the emissions will be. Size and type of vessel, type of cargo, season, different weather conditions. In severe weather you may need to have the main machine stand-by”, says Fredrik Rauer, a project manager at the Port of Gothenburg who leads the study BRAVE ECO - Benchmark for Reduction of Anchoring Vessels' Emissions - Enabling Change of Operations.

The Port of Gothenburg shall reduce its carbon dioxide emissions by 70 percent by 2030. To do this, it will not only be enough to look at ship movements and quay stays – the anchoring time for ships calling at a port accounts for a significant part of a port's carbon dioxide emissions, in some parts of the world up to 50 percent. In the Port of Gothenburg, it is estimated to account for 15 percent.

The project, which also involves the School of Business at the University of Gothenburg, has two main purposes. One is to, through interviews on board ships calling at Gothenburg, find out the reasons behind the anchoring times. With the help of these and AIS data, a calculation model will then be created that shows which vessel types emit the least carbon dioxide per anchored hour. The idea is that the model with minor adjustments can be used in other ports and anchorage areas.

“What we have seen so far clearly shows that there are two reasons for waiting at anchor: you are awaiting a free berth or laycan (the time frame within which the carrier according to a freight agreement has the right to dispose of the ship for loading and unloading)."

The second purpose of the project is to develop proposals for measures that can reduce emissions.

“There are two aspects to work with. You can achieve emission reductions through technical solutions on board and through minimizing the anchoring time. For the latter, both a dialogue is needed with the terminal and with the shipping company. The tanker segment dominates the anchoring times, so we have discussed with them and other stakeholders how we could get a "just in time" thinking. Overall, the parties believe that it is absolutely possible to resolve”, says Fredrik Rauer.

The work with the pre-study will be completed this autumn and the results will be presented here on the Lighthouse website.