LNG fuel in itself may be inexpensive, but the costs in money and time needed to retrofit or new-build a ship with a dedicated LNG propulsion system are very high. By comparison, SOx scrubbers require a smaller initial investment and take less time to install.

Once installed, an LNG-burning system is complex, requiring additional measures to ensure safe operation, maintenance and refuelling. The lack of a consistent regulatory framework for safety and security protocols poses an additional problem. SOx scrubbers need relatively little attention and maintenance.

The clear lack of adequate distribution infrastructure for LNG raises doubts about its availability in the future. Despite the attractive potential of LNG, its availability—or lack—puts it at a major disadvantage. By contrast, SOx scrubbers allow the ongoing use of abundant, inexpensive HFO while meeting IMO and other regulations.

LNG loses the vital race for space. In 2011, a joint study conducted by Germanischer Lloyd (currently DNV GL) and MAN Diesel and Turbo estimated that LNG tank storage can consume as much as 3% of a container ship’s TEU slots, directly impacting profitability. SOx scrubbers only take up at most 0.3% of available TEU slots. Thus, by far, SOx scrubbers are the more compact solution, allowing for greater profitability.

*Costs and benefits of LNG as ship fuel for container vessels: Key results from a GL and MAN joint study