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Technologies for clean sailing. Part 5 of alternatives to marine fuels.

October 29, 2019

There are several ways to meet the IMO's goals of reducing total greenhouse gas emissions by at least 50% by 2050 compared to 2008. In the previous blogs we mainly discussed the use of alternative fuels, but there are also technologies that make clean(er) sailing possible. Scrubbers have been discussed in an earlier blog, and fuel cells have also been mentioned, but there are more possibilities. Part 5 of the series on alternatives to marine fuels.

Wind power

The idea of using wind to power ships is as old as shipping itself. In this day and age, it's called innovative.

The Dutch company Dykstra Naval Architects has designed the Ecoliner, a ship with both a diesel-electric drive and four large sails. In optimal conditions, the sails can provide fuel savings of up to 40%. It has not yet progressed beyond a design, and construction has not yet got off the ground.

The German company SkySails pioneered wind propulsion before. In 2007, the Beluga SkySails was equipped with a kind of kitesurfer, a giant kite. Then an existing ship, the Michael A, was also equipped with this kite. A ship equipped with SkySails would need to burn 10 to 35% less oil. The maximum speed could also be increased by 10%.

Flettner rotors are more likely: large vertical cylinders that rotate continuously and on which the wind exerts a perpendicular force. The shipping company Maersk is going to equip a tanker with these. It will be a ship permanently sailing for Shell Shipping & Maritime. Expectations are that this will lead to fuel savings of 7 to 10%. The design is being made by the Dutch company C-Job Naval Architects. The Energy Technologies Institute from England is also involved in the project. This research institute is also contributing to the financing.

The rotor sails were designed by the Finnish company Norsepower. Norsepower has used Flettner rotors before: on the ro-ro ship Estraden and the ferry Viking Grace.

Photo: Norsepower


Running on batteries is a very plausible clean solution for smaller ships, which (as yet) sail shorter distances. For larger ships, the big problem is that it is not (yet) possible to store enough energy.

DNV GL does expect battery-powered ships to make up a significant proportion of the fleet operating regionally.

Ferries are a good place to start with batteries. In Denmark, the ferries Tycho Brahe and the Aurora of the HH Ferries Group, are equipped with a battery (only). The ferries sail a 4 km route between Helsingborg (Sweden) and Helsingör (Denmark), requiring a battery pack of over 4 megawatt hours.

Norway has already operated an all-electric ferry, the Ampere, since May 2015. Compared to similar ferries running on fossil fuel, the CO2 reduction is 95 percent and the reduction in operational costs is 80 percent. The electric ferry was launched in May 2015, with the aim of reducing both pollution and noise. The ferry is an initiative of Norled AS, Fjellstrand Shipyard, Siemens AS and Corvus Energy. Fifty-three orders have now been placed for it.

The port of Antwerp is also taking the plunge into electric shipping: eleven electric barges will soon be in operation. The barges were supplied by the Dutch company Port-Liner. The electric barges are part of an initiative to reduce the number of truck journeys to and from the port. Antwerp Port Authority is investing € 1.4 million in seven projects, which together should result in a reduction of 250,000 truck journeys. The ships will be equipped with large batteries that can be recharged or replaced when empty. The batteries must ensure that the ships can sail for fifteen hours.

And the GVB, Amsterdam's public transport authority, recently announced that it was putting five fully electric ferries into operation. By 2025, all operational ferries should be emission-free. The ferries are designed to charge when passengers and vehicles leave the ferry. The charging process will take no more than four minutes, which should be enough to operate 24 hours a day without having to plug the ferry in at night. The ferries will have a loading capacity of twenty cars, four trucks or four hundred passengers.

In 2017, the world's first all-electric cargo ship was launched in the Chinese city of Guangzhou. The ship was developed by Guangzhou Shipyard International Company and is fully powered by lithium-ion batteries. The emission-free ship has a range of 80 kilometers, after a 2-hour charge time.

Finally, Damen is building the first fully electrically powered tugboat for the Port of Auckland. The batteries are charged by a 1.5 MW battery charger. That would take just two hours to charge the vessel. The cost of construction is estimated at $8-$9 million, but the lifetime savings will be about $12 million: on diesel purchases and through lower operating costs.


What will the future bring? In the sixth and final blog, the crystal ball is taken out of the closet....