LNG, Methanol, Biodiesel and beyond: What Are the Best Alternative Propulsions in the Shipping Industry?
As for many other sectors, sustainability has also become an integral part in the shipping industry. Shipping companies are actively working on using alternative propulsions for their vessels such as LNG gas, methanol or biodiesel. While thus far there is no one-size fits all solution, some shipping companies are already using these more sustainable methods of propulsion. But what alternative propulsions do already exist and what can we expect in the future?
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According to the International Energy Agency, global shipping accounted for 706 million tons of CO2 in 2022. Thus, the acceleration of decarbonization is an issue being discussed in detail within the shipping industry. It is an undeniable fact that supply chain emissions are responsible for a significant amount of worldwide emissions. Hence, some carriers are already willing to pay a higher price for sustainable methods of transport and a more sustainable infrastructure. One solution could be more climate-friendly supply-chain coalitions between carriers and other parties involved in providing a seamless supply-chain, o improve the cost factor – as prices for sustainable fuels, for example, remain high due to their limited availability.
Ship Green – our solution to actively avoid emissions
Hapag-Lloyd has begun to tackle this challenge with its solution Ship Green. This solution brings us one step closer to being more climate friendly. The service, available in the Online Business Suite, provides more sustainable ways of shipping goods through emissions avoidance. You are able to choose from three different options and can avoid either 25, 50 or 100 percent of emissions caused on the ocean leg part of your shipment.
While Ship Green is based on the utilization of biodiesel made from waste- or residue-based feedstock, which has a lower carbon footprint than traditional fossil fuels, there are other forms of alternative propulsions:
LNG - liquified natural gas
LNG stands for liquified natural gas. Ships that are being propelled with LNG can, in comparison to conventional diesel fuel carriers, significantly reduce sulfur dioxide and lower nitrogen oxide as well as CO2 emissions, which makes LNG an attractive alternative in the industry. When natural gas is being compressed instead of liquified, it is called compressed natural gas or CNG. Thanks to compression it is more suitable for smaller ships than LNG, which requires a larger storage place.
Hydrogen-powered vessels
Some car manufacturers already use hydrogen as an admission free solution for their vehicles’ engines as an alternative to electric cars. Hydrogen powered fuel cells can also be an option for carriers. Clean hydrogen can be easily produced through water electrolysis. The fun thing is that the emissions of this type of engine are drinkable water.
One of the first hydrogen-powered vessels is the Japanese Suiso Frontier (Suiso is Japanese for hydrgen – so it’s a very fitting name), build by Japan’s Kawasaki Heavy Industries. It was put into service in 2020 and completed its first international voyage to Australia in 2022. The goal is to have a viable commercial routing offer in the 2030s that will feature more hydrogen-powered vessels.
Methanol
Methanol fuel ships are also considered an attractive alternative to vessels propelled with biodiesel. The first dual-fuel methanol-fueled tanker was built in 2016. While methanol, if it is being burned in an engine, does have some direct emissions of carbon dioxide and other pollutants, the amount is noticeably lesser than an engine using biodiesel. Important, regarding the approach of methanol for ship engines, is also its production. This is closely linked to the source of the natural gas out of which methanol is being produced. Thus, grey and brown methanol are made with fossil-fuel feedstocks. Blue and more carbon-neutral methanol is being produced using captured carbon, renewable electricity, or green hydrogen instead of natural gas.
Ammonia
In November 2023 the world’s first container ship powered by clean ammonia set sail: the Yara Eyde. The vessel is supposed to sail emission free between Norway and Germany and will operate between Oslo, Porsgrunn, Hamburg and Bremerhaven. In contrast to biodiesel, ammonia in molecular form does not contain a carbon atom. Therefore, it does not emit CO2 during combustion. At the same time, ammonia has an energy density that is similar to methanol but is more favorable than hydrogen, because it requires less cooling. Ammonia can be synthesized from hydrogen which requires less energy than the synthesis of methanol or e-methane. Because of this, ammonia production is cheaper than the other zero-emission fuel options mentioned before.
Electric vessels
The first fully autonomous eletric vessel also stems from Yara and took the seas in November 2021. Its name is Yara Birkeland. With a length of about 80 meters, the ship can save 40,000 trips by trucks, which equals a reduction of 1,000 tons of CO2 emissions per year. The vessel is meant to transport fertilizers from port to port. However, Yara Birkeland is not the only electric ship that has made its debut in recent years. In August 2023, the largest fully electric ship has taken to the sea in China. According to the shipping company Cosco, which owns this vessel, it is supposed to save 32 tons of CO2 emissions per day. Moreover, it is supposedly able to sail 1,000 kilometers without having to charge its 36 battery containers. These batteries take up 5% of the loading capacity, which leaves room for. The ship is thus able to transport up to 700 cargo containers.
Wind-powered vessels
Back to the roots: Cargo ships have been powered by wind for centuries - and probably will be in the future. In December of 2021 Airbus' subsidiary Airseas began testing a container ship that is partially being propelled by wind power. To do so, the engineers have developed a wind-kite, that is approximately hung 200 meters height, that can be connected to the vessel in situations where the high winds are strong enough to pull the ship forward. The vessel is therefore not entirely propelled by wind power but only when there is a sufficiant amount of wind. The new approach aims at reducing fuel consumption by about 20 percent. Moreover, the vessel's steering mechanism is supposed to be almost entirely automatic, to make it almost autonomous.
Combination of different propulsions
As development progresses, some vessels are also being designed to use different alternative propulsions. Examples include hybrid systems that combine electric motors, diesel and engines and batteries to optimize the use of energy. These various forms of combinations are also a solution for some of the challenges that the industry faces. In fact, most of the vessels on our seas are already using a somewhat hybrid solution using diesel engines that are semi-electric so as to save diesel and emissions.
The pros and cons of alternative propulsions
Thus far, the most prevalent disadvantage of alternative propulsions can be attributed to costs, as mentioned before. However, as global warming accelerates, and especially major companies are expected to provide a report on their environmental, social and governance factor (ESG) ratings – sustainability is a major part of ESG – shipping companies must make the calculations and see what they can invest in alternative propulsions. As explained above, the advantages of many of these alternative propulsions are clear – some decrease carbon dioxide emissions others do not produce any emissions at all.
Many possibilities on the horizon
As it becomes clear by looking at the list of alternative propulsions, there are many possibilities that aim at reducing emissions in the shipping industry. Some can even reduce costs in the long run. While some of them might just be in a testing phase, others are already successfully implemented and have become an important part of the supply chain. Which of these alternative propulsions will play a major role in the future of cargo shipping remains to be seen. Hapag-Lloyd, however, has made the vow to play an important role when it comes to the reduction of CO2 emissions and already set the sail towards these goals with solutions like Ship Green and plans to test further alternative propulsions such as sailing vessels.
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