Green Ship Technology – Fuel CellsDue to the ever increasing levels of greenhouse gases, the world is now heading in for greater energy efficiency measures than it had ever before. Statistics have indicated that transportation accounts for nearly 28% of the global emissions, out of which ships emit only about 7 % of the emissions. The IMO has come out with newer strategies to limit the impact of shipping on the environment and the basic condition is to demonstrate a technology for reduction of emissions within one of the four focus areas-Machinery, Propulsion, Operations and Logistics.

Although shipping consumes only 5 % of total world oil consumption(for transporting 90% of world trade).Responding to the need of shipping industry, significant development has been made in the field of Dual Fuel Engines, Diesel-Electric Propulsion, Solar Panels and Fuel cells etc. Success of on land as prompted it on board. Fuel Cell is essentially, an electrochemical device that combines hydrogen and oxygen to produce electricity, with water and heat as by product. A given set of fuel cells have the tendency of generating power in the range of 330KW up to 5MW. Various types of fuel cells:-Photon Electric Membrane(PEM), Solid Oxide fuel cells(SOFC), Direct methanol fuel cells, Alkaline fuel cells, Urine fuel cells(UFC), Molten carbonate fuel cells(MCFC) etc. Each fuel cell has an electrical efficiency of 50-70% with various operating temperature.

Mainly, SOFC,UFC ,MCFC are used in marine application. All the three have a good efficiency of 50-65%. These fuel cells are being used as an APU on various ships. An offshore vessel named ‘VIKING LADY’ uses this fuel cell technology plant, produces 330kw of power and contributes in main propulsion. The commonly known limitation is the carriage of Hydrogen as a fuel in bulk. An external hydrogen generator would be required, as refilling of the Hydrogen bottle would not be an economically feasible solution.

Inspite of the above mentioned drawbacks, fuel cells if employed onboard would definitely bring about a revolutionary change on the impact created by shipping on the world environment. Studies have indicated saving of about 20% on fuel and significant reduction in the SOX and NOX

emissions by as much as 30-35%, upon employing fuel cells onboard for means of alternate propulsion. Thus, this paper provides a review of the advancement in this area of technology that may lead to reduction in environment problems and promote green ships.