The shipping industry is a major industrial emitter of greenhouse gases — accounting for between 2 to 3% of all global emissions.
Ships emit less CO2 per ton per mile than other means of transportation. However, the growing international discussion around climate change has industry leaders looking for alternatives to traditional fuel options like oil and marine gas. What’s needed is a way to reduce costs and make the industry more sustainable.
Alternative fuel options — like liquified natural gas, biofuels and hydrogen — may help the industry reduce overall greenhouse gas emissions and more easily comply with new global shipping standards.
Here are some new alternative fuel options, how practical they are and what impact they could have on the shipping industry if adopted at scale.
Liquified Natural Gas
Liquified natural gas is created by very high pressures and low temperatures. It is derived from natural gas and is a nonrenewable fuel source. While it produces less greenhouse gas emissions than current fuel sources, it isn’t clean — emitting just around 25% less CO2 than marine gas oil.
However, these fuel options may provide a valuable stopgap for the industry while shippers investigate and test other, more sustainable fuel alternatives. Liquified natural gas is already widely used by the industry, with shipping rates topping $100,000 a day as of December 2020.
They offer significant improvement over heavy fuel oil and marine gas oil, helping to cut down on the industry’s overall emissions without causing major disruptions.
Of all available fuel options, liquid hydrogen — when produced using renewable energy — would likely be the cleanest choice.
Liquified hydrogen has potential as a fuel option for shippers, but it requires significant storage volume and is highly volatile.
Hydrogen fuel cells, better known as an alternative to combustion engines for cars, offer similar advantages and disadvantages. While clean, quiet and highly efficient, the cells are expensive, difficult to store and still mostly experimental.
As with other renewable fuel sources, hydrogen also requires a water-intensive production process. Most manufacturers use either steam-methane reforming or electrolysis, the splitting of water molecules with electricity, to produce hydrogen.
While a few shippers, like Kawasaki, have already begun experimenting with liquid hydrogen transportation, we haven’t seen major adoption of hydrogen-powered ships just yet. Still, the fuel source’s extremely clean nature may make it a valuable option for those wanting long-term sustainability.
Some shippers are also investigating the use of liquid biofuels — various types of diesel and gas produced from biological materials, like dry plant matter and food waste.
Greenhouse gas emissions produced by biofuels vary depending on the method used to create them. Some biofuels are comparable to marine gas oil in terms of carbon dioxide emitted. Others can be very clean — producing almost no CO2 emissions.
Biofuels may provide a valuable in-between option for shippers — cleaner than liquified natural gas and more practical than difficult-to-store liquified hydrogen.
These Alternative Fuel Options May Be the Future of the Shipping Industry
For shipping industry leaders wanting to reduce their CO2 emissions, these fuel options provide one set of options.
Liquified natural gas is already widely used, and while not entirely clean, produces significantly reduced emissions compared to conventional fuel options. Biofuel and hydrogen are also possibilities — though storage difficulties may make hydrogen less practical in the near future.
Jane covers topics in green technology and manufacturing. She also works as the Editor-in-Chief of Environment.co.