According to ABS, there are three emission-free drivers that are not talked about enough: electrification, nuclear energy, and the role of advanced digital technologies.
As explained in the 2024 Outlook report, these powerful resources can be linked and offer high potential to advance decarbonization of the shipping industry. Alternative fuels can be viewed as an essential stepping-stone to electrification — meaning the replacement of fossil fuel technologies and processes like internal combustion engines. Furthermore, digitalization continues to evolve at a rapid pace and can further support the pathway to zero emission.
Key points to consider
Low-carbon fuels and carbon capture:
- Lower industry emissions while technology develops from diesel electric to hybrid systems and ultimately to fully electric.
- Requires sufficient battery technology and charging hub networks to support longer voyages with larger ships.
Battery technologies:
- Lead acid batteries: Long-standing technology but with low energy density.
- Lithium-ion batteries: Improved technology now widely available.
- Emerging technologies: Includes lithium-polymer, metal halide, and redox flow batteries, driving up energy density.
Fuel cells:
- Electrochemical devices that convert fuel into electricity.
- Example: Hydrogen fuel cells produce electric current with water and excess heat as byproducts.
- Offer better energy density than batteries, do not require recharging from land, but use expensive materials and are subject to transient loads.
Other electrical storage technologies:
- Potential future technologies include photovoltaic panels and super-capacitors.
Nuclear energy:
- Acts as an enabler for clean fuels and a producer of hydrogen.
- Serves as a power source for primary movers.
- Advanced reactors offer advantages in producing e-fuels (e.g., e-ammonia, e-methanol, pink hydrogen, carbon-neutral renewable diesel).
Digitalization:
- Continues to evolve rapidly and can support the pathway to zero emissions.
#1 Electrification
Fuel cells have emerged as a promising solution for decarbonizing marine transportation. Unlike traditional combustion engines, fuel cells generate electricity through an electrochemical process. Hydrogen serves as the primary fuel, producing only water vapor as a byproduct.
In the framework of sustainable maritime transportation, the available fuels for fuel cells — hydrogen, ammonia, renewable methane, and methanol — as well as the pre-processing technologies for them are examined. Based on different types of electrolytes, the fuel cells for maritime applications are categorized.
In summary, each type of fuel cell has its advantages and challenges. The fuel cell evaluation depends on factors such as efficiency, operating temperature, fuel availability, and vessel requirements. So far, PEMFC and SOFC have been successfully adopted and operated on marine vessels. When energy efficiency, power capacity, and sensitivity to fuel impurities are considered, the most promising solutions are found to be the PEMFC, MCFC, and MCFC types of fuel cells. As technology advances and infrastructure improves, fuel cells will play an essential role in achieving zero-emission marine propulsion.
Meanwhile, Bbttery energy storage systems (BESS) and hybrid systems combine energy storage (vessel batteries) with conventional engines. Ships with hybrid propulsion systems can meet their propulsion requirements in various scenarios by combining fuel-burning engines with electric motors and batteries.
These technologies can lower maintenance costs, increase fuel efficiency, and aid regulatory compliance. Hybrid systems are ideal for vessels that have flexible operation profiles and running hours with varying power demands. The marine electric vehicle market is driven by on-water applications, which are being driven by the growing emphasis on environmental sustainability and the reduction of GHG emissions.
Battery/hybrid ship propulsion systems have already been applied to power smaller vessels and port handling equipment, and transitioning to larger ships is underway. The maritime industry segments that have the most interest in battery and hybrid systems include ferries, defense vessels, yachts, tugboats, hybrid boats, recreational boats, and unmanned maritime vessels.
#2 Nuclear power as an alternative energy source
Nuclear energy has received increased attention as a possible source of clean energy for decarbonizing the marine industry. Widespread application of advanced reactors may be a key pathway toward achieving carbon emissions reduction and producing clean alternative fuels. This section examines the nuclear energy value chain, including its wide array of possible implementations.
Currently, the civilian use of marine nuclear technology is limited to several vessels operating in the Russian Arctic, including a fleet of icebreakers and a floating power plant commissioned in 2020. Several projects are currently under various stages of development; however, the planned demonstration of several advanced nuclear reactors for maritime applications is possible in many countries over the next decade. Refer to the current list of ongoing projects in Table 5.8.
In recent years, nuclear technology has taken a new direction with the ongoing development of advanced nuclear reactors. Advanced nuclear reactors include several categories of technology in various stages of development. Most advanced nuclear reactors are small modular reactors which typically produce 300 megawatts (MW). Some are microreactors producing less than 20 MW, which may potentially be contained within a standard shipping container. Advanced nuclear reactors may also be designed to be “nuclear batteries,” which are designed to be removed when spent as opposed to being refueled.
Advanced nuclear reactors have many possible implementations within the maritime value chain due to their potential modularity, offering various arrangements of size and power output, as well as advanced safety systems. Other benefits can include low operating pressures and self-adjusting passive systems, potentially making the technology more applicable for widespread use in a marine setting. Other benefits of advanced reactors include their long fueling cycles, the possibility of factory fabrication, and small footprints.
#3 Digital technologies and AI
