Maersk Supply Service reported the anchor handling tug supply (AHTS) vessel Maersk Minder has completed sea trials off the west coast of Norway, following its refit with a new hybrid-electric propulsion system
Maersk Minder is believed to be the world’s first hybrid-electric anchor handler, said the Danish offshore support vessel (OSV) owner on social media.
“The installation of this battery system is a significant step for Maersk Supply Service and demonstrates our commitment to decarbonising our fleet,” said Maersk Supply Service chief operating officer Mark Handin. “As we continue to follow an “every step matters” approach, this represents an important milestone in our long-term journey towards carbon neutral operations,” he added.
The retrofit is one of the investments being made by Maersk Supply Service to advance its ambitious goals to halve its carbon intensity by 2030 and reach net-zero operations by 2040.
Mr Handin highlighted the company’s efforts on decarbonisation at the Annual Offshore Support Journal Conference, Awards & Exhibition in London in June.
A major OSV player, Maersk Supply Service took home OSJ’s Shipowner of the Year Award and ESG Award for 2022 for its safety, technical excellence and implementing environmental projects.
The battery refit
On 31 March 2022, Maersk Minder docked at the Norwegian shipyard Fitjar Mekanisk Verksted, where the container-based Wärtsila HY hybrid power system was installed. Expectations are that the battery-hybrid system will reduce the anchor handler’s fuel consumption – and associated carbon emissions – by 15%, as well as reducing the vessel’s maintenance needs and improving its operational performance.
The battery system is comprised of an energy storage system incorporating 132 smaller batteries and a transformer, which is controlled and monitored via an energy management system.
Maersk Supply Service said one of the emissions-reducing advantages of the hybrid system is the facilitation of peak shaving, meaning the batteries can deliver extra power quickly to avoid spikes in power consumption. This ultimately leads to a significant efficiency improvement, since the motors can run with optimal load and use the batteries to absorb a large part of the load fluctuations.
BWTS and SCR installed
While at the shipyard, Maersk Minder underwent additional retrofits to improve its emissions profile and comply with ballast water treatment requirements. A selective catalytic reduction (SCR) system was fitted to capture nitrogen oxides (NOx) produced by the ship’s diesel engines. As a result of the SCR refit, Maersk Minder’s NOx emissions will be reduced by an average of 80%. The SCR works by mixing a urea solution with the exhaust fumes, creating a reaction that removes the NOx from the flue gas stream.
What’s more, this brings Maersk Minder in line with IMO Tier III emissions standards, even though they are only recommended for vessels built after 2021.
The final major upgrade was the installation of a ballast water treatment system (BWTS), designed to remove biological organisms from ballast water and prevent accidentally carrying and introducing aquatic invasive species into new waters. This particular BWTS uses a two-step process, first filtering the ballast water through a miniscule 20µ filter, then using UV light to eradicate any remaining hitchhiking aquatic lifeforms including bacteria, microbes, small invertebrates, eggs, cysts and larvae of various species. This cleansing process fulfils yet another IMO requirement and is critical to protecting marine ecosystems, by preventing the spread of invasive species that can out-compete their native counterparts.
The trials covered tuning Wärtsila’s battery system and Kongsberg Maritime’s dynamic positioning system, customer acceptance test, full failure modes and effects analysis proving trials, shore power trials, and state of health trials.
