It is the most important mode of transporting goods. As a key component of globalization, maritime transport handles 90% of trade by volume, but on the other hand is responsible for 3% of global greenhouse gas (GHG) emissions. The low cost of maritime transport and its excellent returns are due to the increase in vessel size and the use of heavy fuel oil, a cheap, low taxed, but highly emitting fuel.
The International Maritime Organization estimates that the industry will experience strong growth over the coming decades, with a 130% increase in Co2 emissions. Where does the sector stand in terms of transition, and what technical solutions can improve its environmental performance?
Let’s take a closer look at the challenges of decarbonizing maritime transport.
An ever-growing sector
Mainly used for intercontinental trade, maritime transport has accompanied globalization. In 2019, some 11 billion tons of goods crossed the oceans, a five-fold increase since 1970. Projections suggest that this volume could continue to increase by 35% to 40% by 2050, driven by global population growth.
In terms of emissions per ton of cargo transported, shipping proves to be the least polluting mode of transportation in terms of greenhouse gases. However, its carbon footprint remains significant, and continues to grow due to the increase in international trade. For 2022, this footprint was estimated at 1.1 billion tons of CO2 equivalent, which is 3% of global GHG emissions.
As a result, the International Maritime Organization (IMO) and its 175 member countries have made a number of commitments:
- 1- Reduce greenhouse gas emissions by at least 20% to 30%, by 2030.
- 2- Reduce emissions by at least 70% to 80% by 2040.
While these commitments are more ambitious than those made in 2018, they are still insufficient to align with the Paris Agreement and the 1.5°C target. For its part, the European Union adopted a more ambitious regulation in March 2023. The greenhouse gas intensity of ships transiting within the EU will have to fall by 2% per year from 2025 onwards. To achieve this, the EU is counting on the use of cleaner fuels and energies.
N.B.: One should not overlook the consequences on marine biodiversity, environmental impacts related to port infrastructure, as well as various types of pollution associated with this mode of transport.
Ways to reduce emissions in this sector
While maritime transport has facilitated globalization, it has also greatly contributed to the deindustrialization of certain regions. Relocating industrial facilities closer to consumers could significantly reduce the size of logistics chains, and consequently transport-related emissions. Although difficult to implement, this approach should not be ignored, especially as it serves other interests beside climate concerns, such as governance and strategic independence. In the meantime, it is crucial to replace the 300 million tons of fossil fuels used annually with low-carbon energy options.
Here are the current strategies pursued to propel the fleet of ships:
- 1- Synthetic fuels or biofuels
This is the preferred approach for most of the players in the sector: replacing heavy fuel with synthetic fuels or biofuels. While hydrogen and electric batteries appear to be unsuitable for long-distance transport, due to storage problems, biofuels seem more promising. However, there are several barriers limiting their democratization in maritime transport:
- Competition with other needs
European biofuel production capacity is expected to be only 1.7 million tons by 2030. Yet these biofuels are expected to be used for other purposes, in particular to meet the needs of aviation.
- High production costs
According to a report by ADEME, these new fuels would cost 2 to 8 times more than heavy fuel oil. This additional cost would be difficult to absorb for shipowners, as fuel already accounts for 35% of their expenses.
- Shifting of emissions
When alternative fuels are used, there is a risk of shifting emissions from consumption to fuel production. Therefore, the overall carbon footprint from "well to propeller" may be higher, if fuel production has involved substantial GHG emissions. Even though research in this area is ongoing, there is a compelling interest in rapidly reducing ships’ energy needs.
- 2- Reduce speed to decrease consumption
By reducing ship speed by 10-15%, fuel consumption could be cut by 20-30%. This method, known as "Slow Steaming", has already proven effective during previous crises, such as oil shocks or the 2008 financial crisis. If major shipowners or member states of the International Maritime Organization could reach a consensus on maximum ship speed, this would lead to a significant reduction in fuel consumption and CO2 emissions worldwide. However, a rebound effect could be observed: shipowners might increase their fleet to maintain an equivalent level of service.
- 3- Harnessing wind power for propulsion
According to an exhaustive report published by ADEME in 2022, wind propulsion is gaining credibility as a viable mode of propulsion. The industry has seen various technological advancements in sail design and shape, making it easier to "retrofit" existing vessels. Since wind is a free resource, the use of sails could generate operational cost savings of 5-20% for existing vessels.
For new ships designed with sail propulsion right from the start, around 80% of operational costs could be saved.
The ADEME report also argues that wind can be used as the main engine for a medium-sized vessel on specific shipping routes, such as transatlantic routes. Wind can also act as an additional source of power, for a variety of ship types and sizes, thus stabilizing transport costs. Some 15 large cargo ships, including the TOWT sailing vessel, are already in the test phase, with more expected to join them in the near future.
Focus on sailing and its players
In a 2017 report, the European Commission estimated that there would be between 3 700 and 10 000 sail-equipped vessels by 2030, compared with just a few dozen today. For 2050, the British government estimated a fleet of 35 000 to 40 000 sail-powered vessels. What will these future sailboats look like, based on the latest technologies developed for offshore racing and yachting?
- 1- Classic boats with a sailing option
The goal is to allow the use of wind power as an addition to traditional propulsion or as a new main propulsion source. Here is an overview of the main technologies:
- Kites or towed sails
A large, kite-like sail is deployed in the air to capture the wind. This additional force helps propel the vessel, reducing the need for traditional engines. It's an ecological and cost-effective option for ship operators. Some French companies are at the forefront here, including Airseas & Beyond the sea.
- Rotors
A little more complex, this technology uses a rotating cylinder mounted on the ship to exploit the Magnus effect. When the cylinder rotates, it creates a pressure difference around itself, producing a propulsive force. This method has the advantage of taking up little space on the ship's deck.
- Complete sails
Here, masts and sails are added directly to the ship's deck. This is what Ayro, the French company behind OceanWings, offers. The semi-rigid sails can be seen on hybrid ships like the Canopée.
- 2- Real sailboats
The challenge for the future is also to design new vessels, optimized so that sails are the main mode of propulsion. This is the choice made by TOWT, WindCoop and Neoline. These 3 companies have projects for sail cargo ships that have recently materialized and offer decarbonization rates close to 90%, compared to conventional ships.
LITA.co's opinion:
At LITA, we study all technologies that can reduce fuel consumption and emissions in the maritime freight transport. To meet the challenge of decarbonizing maritime transport, TOWT's approach seems particularly impactful.
Other technologies, including those applying sails to existing cargo ships, offer less appealing decarbonization rates than ships designed for sail propulsion. They often prove capital-intensive and require more significant investments.
However, the sector’s transition will need multiple technologies, including those applied to the existing fleet, with decarbonization performance depending on ship size and business expectations (sailing speed, transport frequency, cargo tracking). TOWT is already considering larger cargo ships to meet customer expectations. In addition to these solutions, the sector must also shrink, and as many goods as possible need to be produced closer to the point of consumption. Some commodities, like those transported by TOWT, cannot be produced in Europe, making their value proposition highly relevant.
Read also our behind-the-scenes article on TOWT's entrepreneurial adventure!
Sources :
https://www.h2-mobile.fr/actus/maritime-hydrogene-exclu-transport-longue-distance/
https://librairie.ademe.fr/cadic/6680/propulsion-navires-par-vent-rapport.pdf