Decarbonizing Marine Fuels: Key Strategies and Innovations for a Sustainable Future

As per International Maritime Organization (IMO), the shipping industry’s annual Greenhouse Gas (GHG) emissions total more than one billion tonnes – more than any single country’s emissions outside the world’s top five emitters – highlighting just how important the need for decarbonization is. As per IMO regulations, the shipping industry has set a course for decarbonization to reduce at least 50% of total annual greenhouse gas (GHG) emissions from international shipping by 2050, compared to 2008 levels. At the same time, considering the demand surge in the shipping sector, there is a dire need to meet increasing fuel demand sustainably. Decarbonizing marine fuels is a critical part of this effort, as the CO2 intensity, i.e., emissions per transport work, must also be reduced by at least 70% within the same time frame, while a 40% reduction in CO2 intensity by 2030 has been agreed upon. This poses a twofold energy challenge for the shipping industry, which ultimately requires systemic sustainable energy transition pathways. These pathways will radically transform its reliance on heavy fuel oil by replacing it with more sustainable and cleaner energies that take carbon out of this transport mode. To reach these ambitions, technical and operational energy efficiency measures will be essential, but not sufficient by themselves. Therefore, low-carbon or carbon-neutral fuels, such as new, advanced biofuels and green hydrogen-based fuels (including e-methane, e-methanol, e-ammonia, e-hydrogen, etc.), must be introduced into the fuel mix to achieve the ambitious reductions agreed upon by the IMO.”

Need for decarbonizing bunkering fuel

The main emphasis in mitigating emissions in the shipping industry is on replacing current fossil fuel sources with alternative cleaner fuels. Current fuels used in the sector consist of Marine Gas oil (MGO), Liquified Natural Gas (LNG), and Low Sulphur Fuel Oil (LSFO), which have low sulphur content in line with regulations dictated by IMO’s amendment to MARPOL Annex VI (IMO, 2020b). However, as with all fossil fuels, these fuels produce vast amounts of CO₂ emissions and are the main source of emissions in the shipping sector. To achieve IMO’s goal of reducing CO₂ emissions by 50% by 2050, the shipping sector needs to switch to renewable fuels (IRENA, 2019a). The renewable fuels considered for the shipping industry include biofuel, biogas, methanol, ammonia, H2, and Fuel cells. These options each have their benefits and challenges, which are covered in the sections below.

Alternative Bunkering fuels

In terms of the alternative fuel solutions available today, LNG is the cleanest marine fuel solution available at scale, delivering a range of benefits in helping to drive down GHG emissions whilst improving ports’ air quality with assurance that the fuel does not release any black carbon. Crucially, LNG also provides the gateway to the development of next-generation solutions, including lower carbon bio LNG, which is believed to serve as an important pathway to enable the shipping sector in reaching its decarbonization goals. But overall, the choice of fuel is highly dependent on factors such as supply, engine technology, net environmental performance, and economic viability. Regarding the latter factor, the production costs of renewable fuels and their availability will likely be the decisive factors in the choice of fuel/ propulsion technology (Renewable Capacity Statistics 2019 – IRENA 2019a). This section analyses further the technology readiness and associated production costs of the various renewable fuels considered for the shipping sector.

Apart from commercial aspects, other important aspects to consider about renewable fuels are energy density, volumetric density, and the temperature of the fuel, because these factors impact each fuel’s economic feasibility (IRENA, 2019a). The energy density of the various fuels and the implications in terms of onboard storage are elements that require further analysis. Depending on the fuel of choice and the type and size of a given vessel, cargo capacity and thus cargo revenue could be affected.

Exhibit 1 depicts the differences between the fuels. Liquid ammonia has one-third of the volumetric energy density compared to MGO and two-thirds compared to LNG and therefore requires more storage to attain the same energy output (IRENA, 2019a). Methanol, for example, can be stored as a liquid at ambient temperatures, whereas LNG has to be stored at -162°C, creating difficulties in terms of infrastructure and transport. Each alternative fuel has advantages and disadvantages in terms of physical characteristics, and therefore it is important to consider logistical, infrastructural, and safety aspects when choosing an alternative fuel. The alternative fuels considered for the shipping industry include biofuel, biogas, methanol, ammonia, H2, and Fuel Cells (FC) which are discussed in detail as follows:

Bio LNG: Bio-LNG is a biofuel made by processing organic waste flows, such as organic household and industrial waste, manure, and sewage sludge. When anaerobic digestion of organic waste occurs, biogas is emitted in the process. The main components in this biogas are methane (CH4) and carbon dioxide. To make bio-LNG, the methane is separated from the carbon dioxide and other critical components, and then liquefied. This very complex process increases the energy density 600 times and makes biofuel ideal for heavy-duty and maritime transport.

As the next step in its evolution, biomethane together with LNG can provide a viable pathway to achieve shipping’s decarbonization goal. The biomethane market is growing and has huge opportunities to become a global industry. A study conducted independently by research and consultancy organization CE Delft concludes that BioLNG (liquefied biomethane) is a scalable solution for the maritime sector. It also showed that BioLNG will likely be commercially competitive relative to other low- and zero-carbon fuels. Furthermore, expanding the LNG-fuelled fleet could utilize BioLNG without needing to undertake any modifications, and the existing supply infrastructure will still be fit for bunkering purposes with either fuel. This benefit alone will help in reducing the capital outlay for brand new alternative fuels infrastructure, which it is estimated, could run into trillions of dollars.

Methanol: Methanol, widely known as an alternative fuel for shipping, has seen rising interest in recent years. This alcohol has one of the lowest carbon and highest H2 contents compared to other fuels. Furthermore, methanol reduces emissions of sulphur oxide (SOx), and NOx by up to 60% in comparison to HFO (ITF, 2018), including reductions in particulate matter emissions of 95% (Methanex, 2020). Methanol can be used in both forms, in an IC engine (ICE) or as an H2 carrier for Fuel cells. Methanol’s storage temperature varies between -93°C to 65°C, making it significantly cheaper to store and transport than other fuels such as H2, ammonia, and LNG. The volumetric energy density of methanol is 15.8 GJ/m3 which is the main concern with methanol. In comparison, LNG has a density value of 23.4 GJ/m3 and MGO has more than double the energy density of methanol at 36.6 GJ/m3 (Ming Liu, 2019). Due to this, storage options and fuel tanks for methanol are about 2.5 times larger than MGO (DNV GL, 2019c). Therefore, when using methanol as a fuel, ships are required to double their fuel storage volume, which limits the space that can be used for cargo (Ming Liu, 2019). However, in comparison to fuels that require onboard cryogenic storage, methanol provides more flexibility because it requires a single storage tank.

Utilising methanol as a maritime fuel source benefits from an existing infrastructure for transport and storage (Methanex, 2020). In comparison to HFO, methanol produced from Natural Gas (NG) is estimated to emit 25% less CO₂. However, when considering the life cycle of both HFO and methanol from NG, methanol is estimated to have 10% higher GHG emissions than HFO (Balcombe et al., 2019). Therefore, it is imperative to introduce green methanol production to produce e-methanol and bio-methanol, which are fully renewable and the most sustainable options.

Green/ E- methanol: Green methanol is produced by sourcing H2 from electrolysis powered by renewables and utilising renewably sourced CO₂ from Bioenergy Carbon Capture and Storage (BECCS) or direct air capture (DAC) (Renewable energy statistics 2021 – IRENA, 2021a). Bio-methanol is produced using biomass gasification and reformation. The feedstock for this method is usually forestry and agricultural waste and by-products, biogas from landfill, sewage, municipal solid waste, and black liquor from the pulp and paper industry (IRENA, 2021a). As per IRENA’s Decarbonise the Shipping sector by 2050 the falling costs of green H2 coupled with the cost reduction of CO₂ capture technologies should enable 2050 production costs to reach around USD 107-145/ MWh for renewable e-methanol.

As discussed before, utilising methanol as a shipping fuel benefits from a well-established transportation and distribution infrastructure. Furthermore, methanol bunkering does not require special storage, as the fuel is compatible with fossil liquid fuels, and methanol is liquid at ambient pressure and temperature. However, one of the main issues with methanol scalability is the acquisition of cheap and renewable carbon sources for the production of e-methanol. From a technical standpoint, e-methanol is a feasible fuel for the shipping sector due to the limited engine modifications required. From an operating expense perspective, the feedstock of renewable electricity is the main challenge, and from a capital expenditure perspective, the investment linked to the electrolysis itself is a challenge. Yet these latter factors represent a challenge for all renewable e-fuels. Particularly in the case of e-methanol, the key challenge is acquiring sustainable carbon capture, which is costly and adds to the final costs of e-methanol. Despite these challenges, it is important to mention that key players in the shipping industry including Maersk are devoting important resources to and testing the potential of renewable methanol via a pilot project with one of the first renewable methanol vessels, expected to be ready in 2023.

Green/ E- Ammonia: Green/ E- ammonia is made with hydrogen that comes from water electrolysis powered by alternative energy. E-ammonia looks set to be the backbone for decarbonising international shipping in the medium and long term. By 2050, the production costs of e-ammonia are expected to be between USD 67-114/MWh. The validation of ammonia engine designs by 2023 will be a key milestone in unlocking the use of renewable ammonia. While ammonia is corrosive and highly toxic if inhaled in high concentrations, ammonia has been handled safely for over a century. Hence, ammonia’s toxicity and its safe handling should not be considered major barriers. The upcoming development of the ammonia engine by renowned engine manufacturers like Wartsila, and MAN Energy Solutions will positively impact the sector and unlock an attractive market for renewable ammonia producers. The scale-up in production would also result in falling costs for renewable ammonia. Ammonia is indeed the preferred alternative for the shipping sector as it has more similarity to conventional fossil fuel sources in terms of physical characteristics, is simple to store and transport, and as opposed to e-methanol, the production cost of e-ammonia does not depend on the costs associated with carbon capture and removal technology.

Currently, there are no commercial applications for ammonia as a fuel in the shipping sector. There is however great interest in its potential as an alternative fuel, with large investments from South Korea totaling USD 870 million going toward developing greener shipping solutions with a focus on ammonia (The Maritime Executive, 2020a). Ammonia has existing infrastructure in terms of transport and handling, lending it an advantage over other alternative fuels such as H2 (Lewis, 2018). Furthermore, there are established ammonia terminals across the world, with infrastructure in Japan, the United States, Europe, and along the predominant maritime routes.

Each of these fuel options has benefits and challenges summarised in Exhibit 2 as follows:

From an economic perspective, if compared to LNG, this latter fossil fuel is subjected to high market price volatility. A clear example is how the very high price of natural gas is currently troubling many countries across the world, particularly in Europe. While renewable fuel production costs are currently high, in the next decade renewable fuels will become competitive and can shield the shipping sector from the volatility that characterises the fossil fuel market.

Policies Overview

To mitigate the impact of GHG emissions from international shipping, the International Maritime Organization (IMO), has set various measures throughout the years, which culminated in the Initial IMO Strategy established in 2018. The shipping industry has acknowledged its role in climate change and is striving to reduce its environmental impact. The IMO adopted an Initial Strategy in 2018 to reduce GHG emissions from ships, with a vision to phase them out as soon as possible within this century. The initial GHG strategy envisages, in particular:

• A reduction in the carbon intensity of international shipping by at least 40% by 2030, pursuing efforts towards 70% by 2050, compared to 2008.
• Total annual GHG emissions from international shipping should be reduced by at least 50% by 2050 compared to 2008.

There are short-term, operational enhancements available to the industry – such as slow steaming, shore power, and vessel load and route optimization strategies – to improve the efficiencies of the current global fleet. However, reaching the mandated IMO decarbonization targets, ultimately, will require longer-term solutions such as alternative fuels and associated new ship designs, both of which require significant investment in research and development (R&D) before they are ready to be used at scale. While operational enhancements available to the industry will improve the energy efficiencies of the current global fleet, longer-term solutions, such as alternative fuels and associated new ship designs, are necessary if the shipping industry is to achieve the IMO 2050 target. These solutions require significant investment in research and development (R&D) before they are ready to be used at scale.

While the establishment of targets for reducing GHG emissions in the shipping sector is relatively recent, since 1960, and particularly with the adoption of Annex VI – Prevention of Air Pollution from Ships in 1997, the IMO has been working on regulating the airborne emission of SOx, NOx, ozone-depleting substances (ODS), volatile organic compounds (VOC) and shipboard incineration. The underlying objective of this has been to tackle the detrimental impact of these pollutants on human health and the environment.

More recently, the IMO has taken significant steps in limiting SOx emissions. As indicated in MARPOL i.e. Maritime pollutants Annex VI regulation 14, by 31 December 2019, all fuel-oil shipping operating outside Emission Control Areas must be limited to 3.50% mass by mass (m/m). Starting in January 2020, this requirement will be further tightened to 0.50% of the “fuel oil used on board”, a term that includes the emissions from main and auxiliary engines, as well as from boilers.

To achieve these ambitious targets, the IMO suggests the following paths:

• Use a compliant fuel oil with low sulphur content (<0.50% m/m).
• If exceeding 0.50% sulphur content, use an equivalent cleaning means, e.g. exhaust sulphur scrubber.
• Replace the use of high sulphur fuels with alternative fuels, e.g. LNG, methanol, and others.
• Use onshore power supply during docking periods.

From the perspective of a ship owner, considering the emissions reduction timescales for sulphur and CO₂, the key driver that could result in a reduction of GHG emissions for the shipping sector is the MARPOL Annex VI regulation and not necessarily the IMO strategy on reduction of GHG (IMO, 2018). Furthermore, given that the regulatory framework for controlling, supervising, and enforcing low sulphur content in fuel is more thorough, GHG emission reductions are likely to depend greatly on the method for reducing sulphur emissions applied by the ship owners. In this regard, the responsible party for controlling the sulphur limit depends on the flag state of the ship. Hence, developing countries such as Panama, Marshall Islands, and Liberia must have the necessary means and skills to control compliance with the sulphur limit and issuance of the International Air Pollution Prevention (IAPP) certificate.

Similarly, sanctions need to be set by the flag state and/or port state, depending on the situation. In contrast to the methods of sulphur content control, the IMO has proposed a non-punitive method for reducing GHG emissions through ten market-based measures. These serve two purposes: to provide an economic incentive for the maritime industry to reduce its fuel consumption by investing in more fuel-efficient ships and technologies and to operate ships in a more energy efficient-manner” and to enable the offsetting in other sectors of growing ship emissions (out of- sector reductions)” (IMO, 2019).

While the IMO Strategy for the reduction of GHGs is recent, in July 2011, the IMO took more practical action to reduce CO2 emissions by making it mandatory for ships to comply with the EEDI. This indicator focuses on enhancing the energy efficiency (EE) of engines, as well as of auxiliary equipment. It uses the individual ship design, expressed in grams of CO₂ per ship’s capacity mile. Thus, a small EEDI indicates lower specific fuel consumption and lower CO₂ emissions. The mandatory nature of the EEDI has resulted in the identification of specific activities for improving energy efficiency across the various shipping components. The Global Maritime Energy Efficiency Partnership (GloMEEP, 2019a) has also proposed specific actions for fostering renewable energy and improving EEDI, including fixing sails, adding wings or a kite to support propulsion, including Flettner rotors to generate wind power, and installing solar PV panels for power generation.

Sector Development

• Lloyd’s Register to Investigate Pilbara Potential for Ammonia Bunkering: Lloyd’s Register (LR), the global professional services organisation specialising in maritime engineering and technology solutions, has been selected to undertake key feasibility studies into using clean ammonia to refuel ships at the world-scale ports in the Pilbara region of Western Australia. The announcement follows the signing of a collaboration agreement in August between Yara Clean Ammonia and the Pilbara Ports Authority (PPA).
• TotalEnergies Marine Fuels Successfully Bunkers CMA CGM Containership with Sustainable Marine Biofuel in Singapore: TotalEnergies Marine Fuels has completed the refueling of a CMA CGM containership in Singapore with sustainable marine biofuel. This operation marks another milestone in TotalEnergies Marine Fuels’ ambition to become a key biofuel bunker supplier across strategic bunker hubs by 2030. On 29^thJuly 2022, the 4,294 TEU CMA CGM MONTOIR container vessel was bunkered via ship-to-ship transfer with TotalEnergies-supplied biofuel. The biofuel is made of VLSFO (Very Low Sulphur Fuel Oil) blended with 24% second-generation, waste-based, and ISCC-certified UCOME (Used Cooking Oil Methyl Ester).
• Maersk aims for the first carbon-neutral container ship by 2023: As the world’s largest container shipping company, Maersk has a goal of being carbon-neutral by 2050. A key project in development is the production of three carbon-neutral container vessels that will be powered by zero-carbon methanol. These vessels are estimated to be completed by 2023, seven years ahead of schedule (Milne, 2021). These vessels will be capable of carrying two thousand 20-foot containers and will be able to run on most carbon-neutral fuels, particularly e-methanol and bio-methanol. The push for carbon-neutral fuels and vessels capable of utilising these fuels comes from pressure on the shipping industry to cut emissions by 2050 (Milne, 2021). According to Maersk Chief Executive Soren Skou, this goal requires that the first carbon-free vessels be operational by 2030 (Milne, 2021).
• Japan pushes ahead with ammonia as a shipping fuel of the future: Japan plans to use ammonia commercially as a fuel for shipping to achieve its decarbonisation goals by 2050 (Ovcina, 2020). This is in addition to the country’s use of ammonia as a fuel mix for thermal power generation. Ryo Minami, director-general of oil, gas, and mineral resources at the Ministry of Economy, Trade, and Industry expects ammonia to be used as a commercial fuel for the shipping and thermal power generation sectors in the late 2020s and to be in widespread use by 2030 (Ovcina, 2020). Japan’s plans involve collaboration with resource-rich countries such as Australia as producers of H₂ and the use of this H₂ in ammonia production (Harding, 2020).
• Wärtsilä and Grieg to build ground-breaking green ammonia tanker: In the framework of the Zero Emission Energy Distribution at Sea (ZEEDS) initiative, Wärtsilä and Grieg Edge are running a joint project aimed at developing the first green ammonia tanker to produce no GHG emissions by 2024. This project has support from the Norwegian government in the form of USD 5.34 million. The ammonia is expected to be supplied by a planned green ammonia plant in Berlevåg, Norway (Wärtsilä, 2020a, 2020b). Norway has the largest number of vessels capable of using alternative fuels and high volumes of renewable energy sources, providing the perfect conditions to produce the world’s first green ammonia market, according to Vidar Lundberg, chief business development officer at Grieg Star Group (Wärtsilä, 2020a, 2020b).
• NYK presents its efforts for the introduction of ammonia as a marine fuel: Toshi Nakamura, NYK executive officer, spoke at the “Session 3: Industry Session” and introduced the below points under the theme of “Decarbonization of Shipping with Ammonia as Marine Fuel.”
  • The expectation is that demand for ammonia as a marine fuel will increase significantly in the future.
  • The development of an ammonia-fuelled tugboat and an ammonia-fuelled ammonia gas carrier (AFAGC) by NYK and its consortium partners using the Green Innovation Fund.
  • In particular, Nakamura introduced the receipt of a world-first AiP (approval in principle) for each vessel.
• HyAxiom signs agreement with Shell to decarbonise shipping industry with solid oxide fuel cells: Global fuel cell and hydrogen solutions provider HyAxiomhas signed an agreement with Shell Plc and other parties to power a deep-sea liquefied natural gas carrier with a HyAxiom-developed solid oxide fuel cell to test the technology’s ability to cut carbon emissions from maritime transport.
• Virgin Voyages forms Partnerships with Trio of Sustainable Marine Fuel Providers: Virgin Voyages,a new cruise line with an efficient fleet of ships amongst the youngest in the industry, today announced that it has partnered with independent sustainability experts, the Roundtable on Sustainable Biomaterials (RSB), along with three leading waste-based sustainable fuel providers to deliver low carbon fuels to the marine industry. Argent Energy, GoodFuels, and Twelve are collaborating with the cruise line to further advance Virgin Voyages’ commitment to reaching net zero by 2050.

Future Outlook

In this decade (2021-2030), the shipping industry will witness the practical development and deployment of a range of hydrogen-based and bioenergy fuels, including e-Methanol, e-Methane (synthetic LNG), e-Ammonia and e-Hydrogen. The application of these fuel solutions will center on sector innovation, enabling environment, technology readiness, front-runner initiatives, and pilot trials, which are designed to demonstrate the capability of new vessels in using these fuels on a commercial scale. The scaling up of hydrogen-based fuels is likely to materialize between 2030-2040 as per market projections and in line with the ramp-up of electrolysis to commercial levels.

As per IRENA:

By 2050, shipping will require a total of 46 million tonnes of green hydrogen for e-fuels production.

• 73% will be needed for the production of e-ammonia
• 17% for e-methanol and;
• 10% will be used directly as liquid hydrogen

E-ammonia will be pivotal for decarbonising shipping by 2050.

• 183 million tonnes of renewable ammonia for international shipping alone in 2050 will be needed: a comparable amount to today’s ammonia global production

In the next decades green e-fuels will become more cost competitive, thus allowing for a diversified–decarbonised energy mix.

Hydrogen will most likely remain a favourable option as a future bunker fuel because it produces more energy per unit mass when compared to conventional maritime fuel and generates less GHG emissions. However, certain factors such as the cost of production and the special requirements for storage and transportation impede the widespread adoption of hydrogen fuel. Ammonia, which is considered to be a good storage medium for hydrogen, has a higher volumetric hydrogen density than that liquid hydrogen. However, the amount of GHG emissions associated with the existing ammonia production process (i.e., Haber–Bosch technology) is considerably high. With minor modifications, Ammonia is also compatible with engines, turbines, and burners making it an even more desirable fuel.

While the use of LNG presents a readily available transition fuel for the maritime industry, it is anticipated that the initial stage of the transition to a hydrogen-based economy will involve hydrogen produced from natural gas, which would serve as a bridge between the current fossil fuel economy and the future hydrogen-based economy. Emissions generated by this process can be minimized using carbon capture and storage technology. Many governments worldwide have heavily invested in the development of hydrogen and ammonia fuel production and utilization technologies. Many of the main LNG importers are intensifying their efforts toward the transition to a hydrogen-based economy. Currently, Asia is considered to be the world’s largest consumer of LNG, and gas demand in the next five years will certainly be driven by demand from the Asian market. As more LNG suppliers enter the market, shorter and more flexible LNG contracts have emerged causing a significant impact on the price structure. The current and projected shift in the LNG market justifies the use of natural gas as feedstock for the hydrogen and ammonia production process.

Since the demand for many of alternative clean fuels will increase in the coming years, the demand for shipping companies and ports operators to modify their vessels to operate with cleaner fuels will not only increase with time, but this would yield great commercial benefits for those willing to make an early transition. It is also necessary for strategic decision-making that the future expansion of product offerings from LNG exporters is diversified in line with the global demand trends for cleaner fuels. Future work should involve the application of an interdisciplinary approach to address the multi-dimensional issues related to the transition towards supply chains that are comprised of clean fuels. Moving from nearly zero CO emissions to net zero requires a 100% renewable energy mix by 2050. To achieve this more ambitious goal, taking early action is critical. Some key actions to be taken to facilitate shipping fuel decarbonisation by 2050 is as discussed below:

A. Multi-stakeholder synergies

• Stakeholders associated with the shipping sector such as ship operators, port authorities, shipowners, policymakers, renewable energy developers, and utilities should work in close collaboration to strengthen the consensus to achieve a common decarbonisation goal.
• Enhanced global collaboration must be encouraged amongst the stakeholders involved in the field of exploring sustainable options for replacing power fuels (e.g., shipping, aviation, and energy-intensive industries (e.g., cement, iron, and steel), power suppliers, and the petrochemical sector) to draw synergies and work towards common goals.

B. Policy-driven actions

• Introducing carbon levy: Carbon price can be introduced on conventional fuels which can be changed at later stages as the market for sustainable fuels mature. This will not only aid the deployment of renewable fuels on large scale but will also help in preventing investments in fossil fuel infrastructure that are at risk of becoming stranded.
• A mandate can be established laying out a roadmap for increasing bunkering fuel blends with advanced liquid biofuels and biomethane, followed by launching incentive mechanisms to encourage vessel fleets to shift to green H2-based fuels and other sustainable fuels.
• Sustainability certifications and suitable schemes such as guarantees of origin (GO) can be launched to guarantee ship operators of the renewability index of a given fuel and its sustainable origin. Similar schemes have worked well to promote Solar and wind deployment in the past.

C. Research, development, and innovation

• Research and development (R&D) institutions must engage in analysis of the upstream dynamics of sustainable marine fuels including a GHG lifecycle analysis of the different fuels.
• Efforts should be taken to ensure adequate levels of resources are focused on the development of engine technology capable of harnessing new generation marine fuels thereby ensuring that technology is well advanced and ready to be deployed and scaled up soon.

D. Invest in Renewables and Energy efficiency

• Affordable financing mechanisms can be introduced to foster the development of carbon-zero new vessels and retrofits in existing vessels. Subsequently, ship owners can be encouraged to complete retrofits that enable the usage of renewable fuels, as well as retrofits centered on enhancing performance in existing vessels.
• Investment should be focussed on ensuring an efficient, safe, and reliable supply of renewable fuels for the shipping sector via sector coupling mechanisms among bunkering service companies, port authorities, utilities, and the renewable energy sector.

References

1. IMO regulations
2. CE Delft, study on a scalable solution for the maritime sector
3. Renewable Capacity Statistics 2019 – IRENA 2019a
4. Renewable energy statistics 2021 – IRENA, 2021a
5. Lloyd’s Register to Investigate Pilbara Potential for Ammonia Bunkering
6. Total Energies Marine Fuels Successfully Bunkers CMA CGM Containership with Sustainable Marine Biofuel in Singapore
7. Maersk aims for the first carbon-neutral container ship by 2023
8. Japan pushes ahead with ammonia as a shipping fuel of the future
9. Wärtsilä and Grieg to build ground-breaking green ammonia tanker
10. NYK presents Its Efforts for the Introduction of Ammonia as Marine Fuel at Two International Conferences
11. HyAxiom signs agreement with Shell to decarbonise shipping industry with solid oxide fuel cells
12. Virgin Voyages forms Partnerships with Trio of Sustainable Marine Fuel Providers