The Blue Sky Maritime Coalition (BSMC) released a new report focusing on further supporting the North American shipping industry’s journey toward achieving net-zero GHG emissions by 2050.
The report, a second in a series identifying the pathways and approaches to accelerate the transition to net-zero emissions, looks at the roles of vessel types, inventories and GHG accounting approaches.
Developing recommendations to standardize accounting for GHG emissions within the North American shipping industry is essential in paving the way to net-zero emissions. Distributing this data and making it easily accessible is an important step in expanding the drive to adopt these new technologies and ideas
said David Cummins, BSMC President and CEO.
The report specifically highlights how decarbonizing shipping will require the utilization of multiple fuels and propulsion systems, even within a single vessel category.
In fact, it revealed that emissions associated with North American shipping are not required to be reported under a standardized structure, so different approaches are emerging as voluntary reporting has continued to increase.
Furthermore, it establishes a more detailed assessment of the currently operating vessel categories, their operational constraints and emissions profiles, and the implications for decarbonizing the marine value chain by 2050.
Although there is no “one-size-fits-all” approach to future low- and zero-carbon marine fuels, flexibility and a range of fuels and propulsion systems could be appropriately adopted through advances in technology and regulatory incentives
Mr. Cummins continued.
Refueling needs and infrastructure availability
The length of time a vessel needs to travel between refueling, and its proximity to potential refueling supply infrastructure, directly impacts the type of alternative fuel or propulsion system that are the ideal candidates to support that vessel’s operations.
Some vessels, such as harbor assist vessels, operate for very short durations and remain in close proximity to port infrastructure when they are not working.
Thus, these vessels may be candidates for electrification because they are frequently waiting at port where they could charge between assisting ocean-vessels into port.
However, one of the key roles of harbor assist vessels is to assist ships during emergencies, such as extreme weather events, groundings, and other navigational issues. Thus, these vessels must have multi-day power capabilities even if such capabilities are only used periodically.
In addition, electrification always will require consideration of whether the port infrastructure has the required capacity to support the needed electrification demand.
By contrast to harbor assist vessels, vessels that traverse the ocean must remain under power for many hundreds or thousands of miles before they can refuel.
The amount of battery power and storage required to fully support the power needs for that kind of voyage is currently not practical, so fuels such as ammonia, hydrogen, or bio-fuels (including methanol) may be more feasible solutions for these types of voyages.
Thus, the specific operational bunkering conditions that are currently supported by marine diesel must be considered in determining the most appropriate and cost-effective low- and no-carbon fuels.
Vessel power requirements
A central challenge to adoption of alternative fuels and propulsion systems is the lower energy density of nearly all alternative fuels. Ships are designed so that they are economically viable to operate.
Lower energy density of the alternative fuels as compared to marine diesel means that to achieve the vessel’s need for speed, engine power, idling capacity, etc., the vessel will have to carry a substantially higher fuel volume, in addition to the new tanks, fuel systems, and safety equipment, that certain fuels will require.
Extra weight means additional power required to move the vessel. Batteries must also be considered within this context and offer high power (energy density) and efficiency to provide performance for an adequate duration between charging.
Recharging time represents an unavailable (non-operating) vessel, and must be considered as compared to current refueling times, with the potential for battery exchanges to reduce such charging time.
For some vessel categories and alternative fuel combinations, the volume of fuel that would be necessary to achieve the desired speed and range may not be achievable without reducing cargo carrying capacity, making commercial viability difficult. But other combinations may now, or with expected technological improvements, have the capacity to meet vessel speed and power needs.
Navigation conditions
Navigational considerations are also central to power and range needs of a vessel, and the viability of alternative fuels and propulsion systems. For example, inland river vessels in the U.S. and harbor assist vessels in many ports must navigate shallow waters and confined operating areas.
Inland waterway vessels additionally must contend with challenging river bends and a system of locks and dams. Even new-build vessels for harbor assist and inland-river operations are size, weight and balance constrained given this environment, and may not be able to accommodate certain new fuels or propulsion systems.
This constraint is magnified when onboard fuel infrastructure must be positioned in certain locations on the vessel if that positioning does not align with the vessel’s buoyancy and trim needs.
In contrast to the inland sector, ocean-going vessels may have fewer space constraints, but must have long ranges and power reserves to navigate long distances, open ocean weather, and waves.
Some vessels, such as harbor assist boats, or ferries that traverse a single river or lake from shore to shore, have much lower range and power needs. Vessels that typically operate for short durations may be required to operate for longer durations during emergencies, during transit to other ports or harbors for routine maintenance, or when reassigned to a new geography.
These vessels may require more than one fuel/power approach. Additionally, it can be easier in some cases to assure alternative fuel access for vessels that only serve a particular route.