In the shipping Industry, fuel consumption is becoming a critical issue with the increase in fuel prices and the pressure to reduce overall carbon emissions. Reduction in fuel consumption could be achieved by either recovering the heat from the engine exhaust or by using green technology to assist propulsion using direct wind power. The work presented is a comparative assessment of the three main types of ships, namely oil tankers, container carrier ships and LNG Carriers. Results of the study illustrate that, the CO2 emission from a 3,60,000 m3 cargo capacity oil tanker using 10% heat recovery can achieve 11.07 % Energy Efficiency on the Design Index improvement and reduction of 16,358 tones of CO2 emission per year. Using 32ton capacity Sail-kite (sky sail) can achieve 10.6 % EEDI improvement and 15,664 tons of CO2 emission reduction per year. It is believed that the savings result from these add-on systems are both economical and attractive and will hopefully stimulate the shipping industry into selecting such solutions well into the foreseeable future.
Shipping contributes to around 3.3% of the global CO2 emissions (IMO basis 1,046 million tonnes of CO2 in 2007). Due to the absence of stringent policies, it is predicted that by 2050, the increase in ship emissions may grow by 150% or 250% from present levels according to mid-range emissions scenarios - compared to the emissions estimates in 2007 [ IMO, 2009]. According to the International Chamber of Shipping which is, the association representing the global shipping industry at IMO, 90% of the world trade is through international shipping [ICS, 2010]. If this is taken into account together with the UN population forecast for the world population being projected to reach 7 billion in 2011 (from the present 6.8 billion) and surpass 9 billion [UN, 2008] by 2050, this trend in population increase will significantly impact maritime transport, which in turn will increase the CO2 emission contribution from shipping.