Feature 4 | ALTERNATIVE PROPULSION


Overall, the advocates of


the design


claim that it could reduce SOx, NOx and particulate matter (PM) emissions by up to 98%, and cut CO2


by 30%, over the


whole employment cycle in comparison to a conventional harbour tug. The scale of


investigation and


development of fuel cell technology in application to other sectors of industry has provided a spur to work in the marine field, as has the swelling of national and European Union (EU) funding for fuel cell studies. Such financial sponsorship reflects strategic considerations, given the technology’s potential to deliver efficient energy with a much reduced, or eliminated, dependence on fossil fuels, at minimal environmental impact, in tune with today’s much-vaunted, and politically-motivated ‘sustainable economy’ goals. The different forms of fuel cell are


distinguished by the type of electrolyte employed, the oxidant and fuel being oxygen and hydrogen in most cases. When mixed, a reaction takes place in which the two elements combine to form water, releasing energy in the process. This is drawn off across the electrodes of the fuel cell as an electric current, and fed to an electric motor. The only emissions are water vapour and heat. Unlike a battery,


the fuel cell has the potential to deliver power as long as the supply of reactants, the hydrogen and oxygen, is maintained. Freedom from the NOx, SOx and particulate emissions


of


primary fuel in mobile applications such as shipping. Iceland has implemented a strategy


internal


combustion engines, along with high thermal efficiency and quiet, vibration- free running are characteristics of fuel cells that are undoubtedly of interest to whole sectors of the marine market. If carbon-containing fuels such as natural gas are used as fuel, the exhaust will contain carbon dioxide, although reduced by up to 50% compared to diesel engines run on marine bunker fuel.


Hydrogen source One of the key practical issues in a marine application context is the derivation of the hydrogen fuel, in the sense both of whether this is to be derived from hydrocarbon fuel or supplied as pure, liquefied hydrogen, with all the attendant considerations relating to the supply infrastructure and to the processes of electrolysis and reforming. Electrolysis, whereby hydrogen is


obtained from water, requires a large amount of energy in itself, while reformers, which liberate pure hydrogen from gasoline, natural gas, methanol or other fuel, will also need to be fired by


of becoming a hydrogen-based society in future years. A national policy of investigating opportunities for hydrogen fuel and use of fuel cell power has led to a broad-ranging Icelandic involvement in technological research and in the trialling of prototypes and systems to help advance the relevant technologies. Besides the introduction of


fuel


cell-powered buses and the construction of hydrogen filling stations, the strategy foresees the eventual uptake of fuel cells throughout the Icelandic fishing fleet. One of Iceland’s considerable natural resources, geothermal energy, offers a pollutant-free method of producing hydrogen through electrolysis. In addition to the energy resource and


economic implications of hydrocarbon fuel consumption, the country’s considerable fishing fleet is estimated to account for about one-third of all emissions from Iceland, giving added impetus to the rationale for the move to hydrogen usage. Exhaust emissions from transport as a whole represent a very high proportion of all atmospheric pollutants generated in and around Iceland.


SMART-H2 One of the latest initiatives, the SMART-H2 programme, was launched in March 2007 with an anticipated total budget of around US$7-8 million, to demonstrate and test hydrogen-fuelled, fuel cell power plant in marine and road transport, and the associated distribution and supply system for compressed hydrogen. SMART-H2 is scheduled to run until 2010. The centrepiece of the marine work


Fuel cell-powered passenger vessel for Amsterdam developed by Fuel Cell Boat (credit: Fuel Cell Boat N.V.).


42


is a three-year project to design and test an auxiliary based on a hybrid hydrogen engine, installed aboard the 125gt whale watching boat Elding. The unit is intended to cover the vessel’s normal electrical load in regular service conditions, operating off the Icelandic coastline and carrying up to 150 passengers. The silent nature of the auxiliary plant ideally suits the operating profile, whereby the main engine is shut down on encountering surfacing whales, allowing close encounters with the animals, and affording guests the


Ship & Boat International November/December 2008


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