On 31st March 2022, Maersk Minder docked at Fitjar Mekanisk Verksted in Norway, ready to install a battery: a container-based hybrid power system built by Wärtsila. Now fully fitted and functioning, the Wärtsila HY system is expected to reduce the anchor handler’s fuel consumption – and thus carbon emissions – by 15%, reducing the vessel’s maintenance needs and improving its operational performance.
The battery system is comprised of an energy storage system (ESS), comprised of 132 smaller batteries, and a transformer, which is controlled and monitored via an energy management system (EMS). 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.
Vessel upgrades with sustainability in focus
The battery system was not the only upgrade fitted on Maersk Minder while she was in Fitjar, but one of three retrofits aimed at improving ocean health through decarbonization, air pollution reduction, and protecting biodiversity.
Reducing NOx emissions
Nitrogen oxides (NOx) produced by the ship’s combustion engine contribute to greenhouse gases – but by fitting a Selective Catalyst Reduction (SCR) system to the exhaust, Minder’s NOx emissions will now 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.
Moreover, this brings Maersk Minder in line with the International Maritime Organisation’s (IMO) recent Tier III emissions standards, even though they are only recommended for vessels built after 2021.
Testing Maersk Minder’s Dynamic Positioning. Video: Maersk Supply Service / YouTube
Protecting Marine Wildlife
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 BWTS uses a two-step process, first filtering the ballast water through a minuscule 20µ filter (i.e. twenty-hundredths of a millimetre), 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.
Testing the battery system: sea trials and safety
Maersk Minder took to the sea on 11th June 2022, on completion of the installations, to undergo six days of sea trials offshore Bergen, Norway. The testing period covered Wärtsila’s tuning of the battery system, Kongsberg Maritime’s DP tuning and CAT (Customer Acceptance Test), full FMEA (Failure Modes and Effects Analysis) proving trials, shore power trials, and state of health trials.
This rigorous testing process is standard after an upgrade. Still, it is safety-critical since it involves a systematic run down of every possible security scenario to ensure the vessel is fit for operations – and that our seafarers will be safe at sea. Our Employees are one of the core Maersk Values, which underlines the importance of creating the right environment for our people. Safety is integral to our culture and at the forefront of all our operations.
Decarbonizing the OSV Industry
Maersk Supply Service has set ambitious targets to halve its carbon intensity by 2030 and reach net-zero operations by 2040. It has steadily been reducing its emissions since 2018 through a combination of initiatives, such as energy-efficient operations and technical upgrades.
Reference: Maersk Supply Service