The iconic maritime consultancy and classification firm Lloyd’s Register is old enough to see wind power come, go, and come back again. The firm has just put its seal of approval on a new type of sail that will help cargo ships meet the goals of EEDI, a key index energy efficiency and carbon emissions index established by the International Maritime Organization.
EEDI & Wind Power For Cargo Ships
Wind power is free, but the shipping industry gave up sails generations ago, after fossil energy entered the picture. Despite some recent movement in a more sustainable direction, heavy “bunker” type diesel is the current fuel of choice.
“Many vessels still burn heavy bunker fuel, a viscous, carbon-intensive petroleum product that’s left from the crude oil refining process,” our friends over at the technical engineering organization IEEE explain.
With thousands of cargo ships at sea, that’s a lot of bunker fuel. As IEEE notes, cargo ships are the out-of-sight, out-of-mind linchpin of the global economy (except for port communities, which have both ground and maritime pollution right up in their grills). The amount of cargo ferried by water quadrupled to 10.3 billion metric tons from 1970 to 2016, and the number of ships at work today is closing in on 100,000.
Decarbonizing the shipping industry won’t be easy. Consumers could help by consuming less stuff, but consumering is just part of a complicated web of interests keeping boats afloat.
The ultimate responsibility lies with the industry, which has revved up several industry-lead carbon cutting initiatives in recent years. Over and above those efforts is the EEDI, the Energy Efficiency Design Index. Described as the “first legally binding climate change international to be adopted since the Kyoto Protocol,” EEDI launched in 2011 under the United Nations International Maritime Organization.
“The EEDI for new ships is the most important technical measure and aims at promoting the use of more energy efficient (less polluting) equipment and engines,” IMO explains. “The EEDI requires a minimum energy efficiency level per capacity mile (eg tonne mile) for different ship type and size segments.”
Here Come The Rotor Sails
The EEDI is designed to tighten up energy efficiency goals incrementally. Progress has been slow, but electrification and alternative fuels are coming in to play. Tweaks like route optimization can also chip away at emissions, but the most exciting news from a clean tech standpoint is the re-introduction of wind power, including retrofits for older ships as well as new builds (retrofits come under IMO’s EEXI energy efficiency platform) .
Wind power harvesting devices that vaguely resemble conventional sails are part of the mix. The shipping industry is also venturing farther afield, into sails that look nothing like sails at all.
The sail approved by Lloyd’s is a rotor sail. These are vertical, spinning cylinders that look like oversized smokestacks. Though new on the shipping scene today, the basic technology dates back to the 20th century. The initial concept is credited to the Finnish engineer Sigurd Savonius, and they were first tested on a cross-Atlantic voyage in 1926 by the German inventor Anton Flettner, who attached his name to the technology.
That us to Lloyd’s Register and the new Approval in Principal for the Newcastlemax bulk carrier, a new 210,000 DWT (deadweight tonnage) cargo ship designed by the Shanghai Merchant Ship Design and Research Institute and outfitted with rotor sails by the firm Anemoi Marine.
“The Newcastlemax AIP is part of a pioneering joint development project (JDP), signed in 2020, with Anemoi Marine Technologies, Lloyd’s Register, and SDARI and brings together the OEM, classification society, ship designer, and ship owner to develop a series of energy-efficient vessel designs equipped with Rotor Sails,” Anomie explains, adding that the firm Oldendorff Carriers is the shipowner partner.
“The fitting of Rotor Sails on this bulk carrier, as part of our JDP with Anemoi, SDARI and Oldendorff Carriers, will significantly improve the vessel’s efficiency and is a clear example of how energy saving devices can support the maritime industry with impending EEXI and CII regulations,” Lloyd’s adds.
The Power Of Wind Power
Digging into the weeds of the EEDI is a whole ‘nother kettle of fish, so let’s just take Lloyd’s word on that double-digit improvement. As cited by Anomie, Lloyd’s has “validated that the newbuild Newcastlemax would have its EEDI score reduced from 1.92 to 1.37 (29% reduction) by installing six 5x30m Rail Rotor Sails and 1.47 (23% reduction) by installing four 5x35m Folding Rotor Sails. ”
As for how it works, that’s easy. “The Rotor Sails are driven to rotate by a motor,” Anemoi explains. “When a wind flow meets the spinning Rotor Sails, a pressure differential is created. This causes a thrust force which provides auxiliary propulsion to the vessel and can be used to increase the vessel speed or reduce the consumption of the main power unit.”
If you’re wondering how rotor sails deal with bridges, that’s easy, too. They can be designed to tilt into a horizontal position on the ship’s deck in order to accommodate low clearance.
Anomie has added an additional twist. To ensure the sails don’t interfere with cargo loading, their rotor sail system is both tilt-able and movable.
“For vessels with complex cargo operations, such as Bulk Carriers, Anemoi has developed a patented Rail Deployment System. This allows our Rotor Sails to be moved along the deck of the ship so cranes can effectively load and unload without obstruction,” the company explains. “Dependent on deck layout, the Rotor Sails can either be moved from side to side (transversely) or along the length of the ship (longitudinally).”
Next Steps For Rotor Sails
The 23-29% improvement in EEDI could be just the beginning. Last month the Dutch maritime research organization MARIN launched a new European Union-funded initiative called Optiwise, aimed at squeezing more action out of high tech sails by optimizing ship systems around wind power, rather than treating wind power as an add-on.
“Our overall ambition is to develop and employ holistic design and control methods for ground-breaking new ship concepts utilizing wind propulsion while considering realistic operational scenarios. With these methods we expect to realise average energy savings between 30% and 50% when compared to equivalent conventional ships while ensuring operational feasibility in a realistic wind climate,” MARIN explains.
It’s full steam ahead for the effort. Partners in Optiwise include Core IC, SSPA, AYRO, Chantiers de l’Atlantique, Flikkema Innovation Management & Consultancy, Wärtsilä Netherlands, Università degli Studi di Genova, Euronav, and Anemoi Marine as an associate funded through the UK.
In addition, last month MARIN also partnered with the American Bureau of Shipping classification services organization to launch phase two of an initiative called WiSP, for Wind assisted Ship Propulsion.
“WiSP2 will focus on making evaluations within EEDI and EEXI, but also from real operational conditions. The aim is to prove the level of fuel savings ship owners can expect, enabling them to make informed investment decisions, whilst also keeping the upcoming CII requirements in mind, they explain.
Like MARIN and Lloyd’s, ABS is another organization with roots in the era of sailing ships. If US fossil energy interests took cheer from the court-ordered death of the Clean Power Plan, they may want to tuck those pom-poms away and check out ABS’ take on decarbonization. Based partly on the snail-paced uptake of liquid natural gas as an alternative fuel, ABS is steering a course that has more to do with new clean technology and less to do with fossil energy business as usual.
Follow me on Twitter @TinaMCasey.
Image: Rotor Sails courtesy of Anemoi Marine.
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