The need for seaborne transportation will increase significantly in the years to come. At the same time, the fuel oil price is increasing, stricter emission requirements are coming into force, and the public is becoming more concerned about the environmental footprint of shipping. As a result, the industry is investigating alternative fuels for shipping. Liquefied natural gas (LNG) is an attractive option since it reduces the emissions, and is expected to be cheaper than fuel oil in the future because of the large world reserves of natural gas.
The use of liquefied natural gas (LNG) as ship fuel is not a new idea. LNG has been used for many years on gas carriers with boilers (in the case of steam turbine propulsion), four-stroke diesel mechanical propulsion or diesel electric propulsion installed. All these solutions are based on consumption of the readily available LNG as the fuel, and/or boil-off gas from the LNG tanks. In recent years, the LNG infrastructure, particularly in Norway, has developed to the extent that other ship types, like Ro-Ro and smaller ferryboats, use LNG as the fuel, and it is now established as a clean and reliable fuel for propulsion and auxiliary power generation.