The global shipping industry is responsible for 3% of our total emissions of CO2. Green hydrogen fuel, while not yet ready to replace oil or gas bunker fuels industry-wide, does not cause any emissions in use and may be the best possible solution to this problem. However, heavy regulation such as an international carbon tax is required to make sustainable energy alternatives a reality in this industry.
Image Credit: Avigator Fortuner/Shutterstock.com
What are the Problems in the Shipping Industry?
Over nine billion tons of cargo are shipped around the world’s oceans each year. Global trade relies on marine transportation to move containers and solid and liquid bulk cargo between ports, but the shipping industry relies on huge amounts of fossil fuel energy stored in bunkers on board the vessel to make these journeys.
Burning bunker fuel to drive cargo ships currently leads to approximately 3% of all greenhouse gas emissions. Around 18% of some pollutants found in the atmosphere is directly caused by the shipping industry.
As worldwide trade is expected to increase with a growing population, economic development, and more globalization in coming years, so will the shipping industry’s demand for energy.
As well as a heavy reliance on dirty bunker fuels, shipping also has wide-ranging, negative effects on aquatic ecosystems. Ships releasing ballast water have introduced invasive species into new habitats. The industry is responsible for oil and chemical spills worldwide, as well as accidental and intentional deposits of garbage and dry bulk cargo.
Ship-strikes injure and kill rare megafauna in the oceans, and underwater noise pollution from their large engines disturbs many species of sea life. Around ports, the industry causes severe contamination of sediments in ship breaking and transshipment.
Despite this negative reputation, the shipping industry has traditionally been reluctant to adopt measures to limit its environmental impact. These problems have been widely acknowledged by authorities, conservation organizations, and shipping industry leaders themselves – but little is being done. This shows that the shipping industry may require external pressure – such as better global regulation – to change its act and minimize environmental harm.
Hydrogen in the Shipping Industry
There are some pilot projects underway that aim to show that hydrogen – which emits no greenhouse gases when burned, only water – is a viable replacement for fossil fuels in shipping. However, these are currently limited to a small scale on routes that take in visits to refueling facilities.
This is due to a lower energy density in hydrogen fuels now, compared with heavier petroleum. Liquid hydrogen fuel must also be stored at temperatures lower than -253 ℃ in cryogenic tanks. These heavy containers take up valuable space and weight on a cargo ship.
Some researchers are optimistic that hydrogen fuel can overcome these challenges to become a more viable alternative to fossil fuels. However, hydrogen must be green or at least blue if it will have a positive net impact on the environment compared to oil or gas.
Hydrogen is a product of water electrolysis, a highly energy-intensive process. Hydrogen is an unsustainable fuel unless the energy used for this process itself has no negative impact on the environment.
Blue hydrogen achieves this by capturing carbon released by natural gas used to power electrolysis. Green hydrogen is produced using renewable energy sources such as solar or wind.
When Will the Shipping Industry Embrace Hydrogen?
Although other, cleaner fuel types such as methanol and biofuels have been proposed by some in the shipping industry, hydrogen is the only fuel technology we have today that emits zero CO2. It should, therefore, be at the center of planning and decision-making for the industry’s long-term future.
Technical challenges could be overcome in a matter of years, according to some researchers. However, fossil fuels will remain cheaper to extract than hydrogen fuel is to produce – at least in the short-term future. To counteract this, worldwide regulatory measures such as a global carbon tax could provide the economic justification necessary for the shipping industry to fully back hydrogen in the future.
References and Further Reading
Dempsey, Harry (2021) Shipping Looks to Hydrogen as it Seeks to Ditch Bunker Fuel. Financial Times. [Online] https://www.ft.com/content/b3cd9b09-584e-4205-8c98-2185466c9f81
Schrooten, Liesbeth et al. (2009) Emissions of Maritime Transport: A European Reference System. [Online] Science of the Total Environment https://doi.org/10.1016/j.scitotenv.2009.07.037
Walker, Tony R. et al. (2019) Environmental Effects of Marine Transportation. World Seas: An Environmental Evaluation. Academic Press. [Online] https://doi.org/10.1016/B978-0-12-805052-1.00030-9