12
FOGHORN
run into limitations, such as feedstock scarcity and high 
production costs. That’s why attention is also shifting to-
ward non-diesel alternatives. These include options such 
as methanol, ammonia, hydrogen, synthetic methane, 
and other e-fuels. Pure electric vessels are also an option 
in certain cases such as a point-to-point ferry service where 
the charging infrastructure investments can be justified. 
Each brings different challenges, especially when it comes 
to storage, energy density, and infrastructure, as most of 
these require significantly more onboard storage volume 
than diesel. For passenger vessels, where space is already at 
a premium, that’s a major consideration.
Among these emerging fuels, methanol is gaining atten-
tion as one of the more practical options for a wide range of 
marine applications. Methanol stands out because it avoids 
many of the challenges associated with other alternatives, 
as it is liquid at ambient conditions, does not require cryo-
genic storage, and can be handled using modified versions 
of existing fuel systems. For operators, this translates to 
fewer design hurdles compared to other options such as 
hydrogen or liquified natural gas (LNG).
While methanol does require more storage volume than 
diesel, it remains manageable within many vessel designs. 
It offers flexibility across different vessel types and is par-
ticularly well-suited for coastal and short-sea route vessels 
including ferries, tour boats, and other operations with 
predictable fueling access. Another advantage is familiar-
ity, as pure methanol is already produced and transported 
globally, and many ports have experience handling it for 
other industries. The market has also been considering a 
dual diesel/methanol technology, but this requires vessels 
to incorporate separate tanks for each fuel and all the af-
tertreatment technologies to meet EPA Tier 4 or IMO III 
regulations, where machinery space is already tight.
Like other fuels, methanol’s true environmental benefits 
depend on how it’s produced. The conventional (grey) 
methanol, which is produced from fossil fuels, offers lim-
ited carbon reduction and a worse emissions profile than 
standard diesel, while green methanol, produced from re-
newable energy, offers significant potential. If production 
scales, green methanol is expected to play a larger role in 
marine decarbonization.
While methanol is gaining traction, other fuels are still 
part of the long-term conversation. For example, ammonia 
offers the potential for zero carbon emissions at the point 
of use, making it attractive for deep-sea shipping. However, 
for passenger vessels, toxicity is a major concern with am-
monia use, and its storage systems are complex. As a result, 
ammonia is generally viewed as a longer-term option, bet-
ter suited to large, ocean-going vessels.
Hydrogen is another option that has strong environmental 
potential but presents practical challenges as it is very low 
energy density by volume, requires high-pressure or cryo-
genic storage, and there is currently limited infrastructure 
for its widespread use. This makes it more viable for niche 
or short-range applications rather than widespread passen-
ger use, at least for now.
Other synthetic fuels can reduce lifecycle emissions and 
may benefit from existing infrastructure. However, as of 
today, they can be costly to produce, and their availability 
is still developing.
KEY CONSIDERATIONS FOR  
PASSENGER VESSEL OPERATORS
With numerous options becoming available and poten-
tially more on the way, choosing a path forward can feel 
uncertain. In practice, most decisions come down to a few 
key factors:
Vessel Type and Route
Short, predictable routes may allow for more flexibility in 
fuel choice, while longer routes may still favor higher ener-
gy density fuels.
Space and Design Constraints
Passenger vessels often have limited room for additional 
Drop-in fuels will offer a 
practical way to reduce 
emissions … allowing  
operators to make progress 
now while keeping  
options open for the future.
FOGHORN FOCUS

View this content as a flipbook by clicking here.