An anchor handling tug supply vessel (AHTS) operated by Danish offshore support company Maersk Supply Service has returned to service following the installation of a hybrid electric propulsion system.
The refit on the 2018-built Maersk Minder was carried out at the facilities of Norwegian shipbuilder Fitjar Mekaniske Verksted (FMV). The upgrade works included the installation of a container-based hybrid power system. Maersk expects this system to reduce the vessel's fuel consumption – and carbon emissions – by 15 per cent as well as reduce the vessel's maintenance requirements and improve its operational performance.
The AHTS' battery system consists of an energy storage system (ESS) made up 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 quickly deliver additional power to prevent spikes in power-consumption. Maersk said 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.
FMV also fitted Maersk Minder's exhaust with a selective catalytic reduction (SCR) system, thereby ensuring a reduction in NOx emissions. The SCR system works by mixing a urea solution with the exhaust fumes, creating a reaction that removes the NOx from the flue gas stream.
Maersk said this feature enables the vessel to comply with the IMO's recent Tier III emissions standards, even though such standards are only recommended for vessels built after 2021.
Another major upgrade was the installation of a ballast water treatment system (BWTS) designed to remove biological organisms from ballast water and prevent the accidental carrying and discharge of aquatic invasive species into new waters.
The BWTS on Maersk Minder uses a two-step process, first filtering the ballast water through a miniscule 20µ (i.e. twenty hundredths of a millimetre) filter, then using UV light to eradicate any remaining aquatic lifeforms including bacteria, microbes, small invertebrates, eggs, cysts, and larvae of various species. Maersk said this cleansing process fulfills yet another IMO requirement and is critical to protecting marine ecosystems by preventing the spread of invasive species.
Maersk said the installation of the hybrid propulsion on Maersk Minder is in line with the company's aim of reducing its carbon intensity by half by 2030 and achieving "net zero" operations by 2040.
| Maersk Minder | |
| SPECIFICATIONS | |
| Type of vessel: | Anchor handling tug supply vessel |
| Flag: | Norway |
| Owner: | Maersk Supply Service, Denmark |
| Builder: | Fitjar Mekaniske Verksted, Norway |
| Length overall: | 95 metres |
| Length bp: | 81.5 metres |
| Beam: | 25 metres |
| Depth: | 11 metres |
| Deadweight tonnage: | 4,500 |
| Gross tonnage: | 10,181 |
| Maximum speed: | 16 knots |
| Bollard pull: | 230 tonnes |
| Batteries: | 132 |
| Other electronics: | Energy management system |
| Other equipment installed: | Selective catalytic reduction system |
| Crew: | 52 |
