DNV GL has released a paper on the future alternative fuel mix for global shipping. The report explains that while liquefied natural gas (LNG) is expected to be an early success, over time the fuel mix could become increasingly diversified, as over 20% of shipping could adopt hybrid propulsion solutions, using batteries or other energy storage technologies.
The use of alternative fuels has predominantly been driven by the desire to reduce greenhouse gas emissions and the need to meet new air pollution requirements.
DNV GL senior researcher and project manager on the paper, Christos Chryssakis, explains: “The global merchant fleet currently consumes around 330 million t of fuel annually, 80 - 85% of which is residual fuel with high sulphur content. Shipping must change, and we must contribute technical measures, operational measures and alternative fuels to meet the challenges we are tackling.”
Local vs. global fuels
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. Deep-sea shipping needs globally available fuels and so will lean towards using LNG and biodiesel, if it becomes more widely available. Despite public perception issues, nuclear energy may come to be used more frequently in the future, if it can be perceived as a safe alternative.
“While renewable energy, particularly solar and wind, may have some potential to mitigate carbon emissions, this is not seen as a viable large-scale alternative for commercial shipping,” Chryssakis adds.
An evaluation of total greenhouse emissions, from the well to propeller, instead of solely potential to reduce emissions onboard, highlights some major drawbacks for some of the fuel mix options, as does an evaluation of potential availability. 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 t of biodiesel.
The paper features a discussion on ways to overcome the challenges ahead during the transition towards a more sustainable future for shipping. “There is no doubt that adopting new technologies are likely to be a challenge for ship owners. DNV GL is leading the way through our technology qualification processes which are designed to ensure that new technologies work as expected,” Chryssakis concludes.
Adapted from press release by Katie Woodward