While liquefied natural gas (LNG) will be an early success, the future alternative fuel mix for global shipping becomes more diversified with time, as more than 20 percent of shipping could adopt hybrid propulsion solutions, featuring batteries or other energy storage technologies, according to a position paper by DNV GL.
The global merchant fleet consumes about 330 million metric tons of fuel annually, and between 80 and 85 percent of that is residual fuel with high sulfur content, says Christos Chryssakis, DNV GL senior researcher and position paper project manager. The industry must employ green technology, more efficient operations and alternative fuels to reduce greenhouse gas emissions and meet upcoming air pollution requirements, Chryssakis says.
The International Maritime Organization (IMO) regulations will require ships operating within 200 miles of the US to reduce their sulfur emissions beginning in 2015. Additional regulations that take effect a year later will require new vessels to cut their nitrogen oxide emissions.
Some commercial maritime firms including Harvey Gulf International Marine and Sea Star Line are already powering their fleets using LNG.
In the long term, short sea shipping is expected to take advantage of locally produced fuels such as biogas, biodiesel, methanol, shoreside electricity and hydrogen, the report says. Deep-sea shipping needs globally available fuels and so will tend towards LNG and biodiesel, if it becomes available. Nuclear energy suffers from public perception problems but may come to the fore sometimes in the future if it will be perceived as a safe alternative.
An evaluation of well to propeller greenhouse emissions, rather than just shipboard potential to reduce emissions, demonstrates some major drawbacks for some of the options, as does an evaluation of potential availability, according to DNV GL. For example, the availability of land to grow biofuels is a significant barrier to its widespread use, with an area the size of Greece required to produce 50 million metric tons of biodiesel.
Photo Credit: LNG Arctic Discovered via DNV GL