A large shipping company acknowledges its obligations to drive emission reductions through the development and implementation of practical technologies
A large shipping company acknowledges its obligations to drive emission reductions through the development and implementation of practical technologies
Mitsui OSK Lines (MOL) is one of the world’s largest transport companies, controlling around 860 vessels, with a workforce of over 9,200. Operating on such a scale, MOL’s approach to environmental issues can have major international significance.
In his 2010 new-year message, company president, Akimitsu Ashida, highlighted his company’s efforts to address its environmental burden through the development of a series of next generation vessels. MOL has published concepts for a car carrier (Ishin-I) and a car ferry (Ishin-II), which aim to deliver significant fuel economies and emission reductions. President Ashida says these proposals are not nebulous ideas about ships of the future but are soundly based on progressing and refining existing technologies and, as such, they are eminently feasible.
Ishin-I, the car carrier, is a striking looking vessel because virtually the entire external, horizontal surface is covered with an unbroken array of solar panels. MOL says that solar power can deliver up to 1,000kW on a larger hull, and this energy can be stored in a 15,000kW bank of rechargeable lithium ion batteries. Aside from energy savings achieved at sea, this combination of solar power and significant storage helps to achieve the company’s target of zero emissions when in port.
MOL says that these projections build on experience gained from the use of smaller installations already in use, notably on the 2008 car carrier, Swift Ace, which has a 20kW solar facility. Marine solar power generation arrays must overcome salt damage, vibration and other conditions unique to shipboard operation to work effectively, says MOL.
This use of renewable energy represents 3 per cent of MOL’s overall target of a 50 per cent reduction in CO2 emissions for Ishin-I, while further savings are delivered by a mix of existing and developing technologies. An optimum voyage support system, which reflects the real time operational status of the vessel, will deliver the shortest and most fuel efficient route.
Meanwhile, ongoing refinements to MOL’s Courageous Ace superstructure form will reduce wind pressure from the bow and sides while the teardrop shape of the stern will also smooth the wind flow. Underwater savings will result from the hull design and the use of ultra-low friction paint, and optimising the engine system will control the main engine fuel supply, according to weather conditions. Exhaust gas energy will be recovered and re-used.
MOL says improved propulsion efficiency can deliver significant savings, achieved by employing a contra-rotating propeller system that combines a diesel engine with an electric motor, placing a pair of propellers facing each other at the stern. The company says that the aft propeller absorbs the rotational energy of the forward propeller, greatly increasing efficiency. Ishin-I will also take advantage of the latest in advanced Propeller Boss Cap Fin (PBCF) technology, developed in house and already installed on more than 1,700 ships, according to MOL.
By 2014 it is anticipated that the Panama Canal will be able to accept vessels with a breadth of 48.8m. MOL says if demand exists it will be able to increase the size of car carriers, leading to further gains of up to 15 per cent in propulsion efficiency through the use of twin propeller shafts, achieving the 50 per cent target.
When asked about the additional costs and the anticipated break even point for Ishin-I, Yoshikazu Kawagoe, general manager of MOL’s ship planning and development group (technical division), said he could not answer questions about specific costs because MOL has no immediate intention to construct the ISHIN concept vessels incorporating all the proposed developments.
Instead, he said that, “We believe the construction of Ishin vessels will become a realistic option, once application cost effectiveness of each technical element and its demand become more favourable in the near future. There is an ongoing programme for the incorporation of technical elements into our vessels as they become cost effective.”
He says this is especially true in the case of rechargeable batteries and solar panels, and he notes that in January, MOL announced that its joint research and development project will be incorporated into a government-industry initiative aimed at reducing CO2 emissions; this is sponsored by Japan's Ministry of Land, Infrastructure, Transport & Tourism. MOL will develop a hybrid power supply system by combining solar power generation technology with lithium-ion batteries; it will then construct a car carrier equipped with the system, scheduled for launch in 2012, to assess its CO2 reduction effect in operation.
Technologically, the Ishin-II ferry concept shares a great deal with Ishin-I, although zero emissions in port will be achieved by the use of shore power. MOL says that the use of LNG as fuel will not only reduce CO2 emissions at sea but also cut emissions of NOx, SOx and particulate matters.
It is also proposed, that on Ishin-II, hull friction drag should be reduced by the use of air layer lubrication technology. Minute air bubbles will be released under the hull, creating a ‘friction busting’ air layer that covers the vessel’s bottom. MOL says that collecting and recirculating the air will save even more energy. MEC
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