High on the list of factors that may influence an operator’s choice of LNG as fuel is compliance with the requirements of Marpol Annex VI after 1st January 2020. Factors considered in these investments will have included the size of the fuel tanks, a cost benefit evaluation of dual-fuel capability on auxiliary engines and boilers and whether to use low pressure or high-pressure engines and supply systems.
As a general rule, the cost of building a new dual-fuelled vessel is approximately 20% higher than building a conventionally-fuelled vessel.
A large and growing number of OSVs operate under environmental class notations, like DNV GL’s “Clean Design”. “Clean Design” is a voluntary environmental class notation that requires owners and operators to design and operate their ships in an environmentally sustainable manner. The aim is to reduce the emissions from each vessel, so that the overall environmental burden from shipping is reduced.
One of the requirements of this notation is that emissions to air are controlled within strict limits. The emission levels in DNV-GL’s rules are lower than those in Marpol Annex VI.1
1Reprinted from Offshore Support Journal. The entire article can be read at https://www.osjonline.com/news/view,the-commercial-case-for-lng_53808.htm