The ferry industry is leading shipping's drive to decarbonise. There are plenty of opportunities open to this diverse sector to reach its goals. From flexible engine and propulsion technologies to electrification, hybridisation and future fuels, we take a look at the top eight.
Driven by pressure from the passengers and businesses it serves and increasingly strict global and local regulations, the ferry industry is among the first to target zero-carbon operations. Its diversity, encompassing everything from small commuter vessels to large RoRo and RoPax ships, means there is no one-size-fits-all solution to decarbonising this sector.
Many ferry companies operate with slim profit margins, and demanding schedules are part and parcel of their daily reality. New technologies to improve vessel efficiency and cut emissions need to be introduced with an eye on minimal service disruption and maximum return on investment.
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From bow to stern and everything in between, let’s take a look at what’s on offer to help ferries of all shapes and sizes decarbonise.
Once the sole power source for ferries, engines are increasingly accompanied by electrical sources either onboard or at port. This will not change in the foreseeable future for all but the smallest vessels and those operating short routes. However, operators will increasingly choose engines that are able to burn low-carbon fuels and which can operate in at least partially electrified setups.
An example is a hybrid setup between mechanically driven main engines combined with diesel or gas-electric machinery, all supported by batteries. This type of setup:
The ferry engines of the future will need to be capable of using multiple fuels, and increasing hybridisation will place further demands on integration. And with future fuels likely to be more expensive than conventional fuels, fuel efficiency is key to making them a viable option for ferries.
Even though engine demands are changing, it is still crucial to look for engines that provide:
For high-speed ferries, reducing speed to comply with regulations like CII is not an option. This makes efficient and fuel-flexible propulsion even more critical. When correctly specified and paired with the right engine, they offer unbeatable efficiency above 25–30 knots compared to other propulsion methods.
Waterjets need to generate as much thrust as possible from the input power available and have robust mechanical integrity. They should:
Partnering with a single OEM that can offer the whole package will mean an optimised drivetrain in terms of performance, fuel consumption and OPEX. It also reduces risk by minimising complexity in terms of both vessel design and ongoing maintainability.
Thrusters are critical for ferries of all types and sizes, providing the power for safe, accurate manoeuvring, especially when in port. Thrusters must be carefully integrated with your vessel’s propulsion and engine control systems. This means taking care in the early design stages to identify the optimal number of thrusters and the correct thrust and power output for your application. Doing so will helping to optimise CAPEX and operational efficiency.
Calling in hydrodynamic expertise is a huge benefit because it will help you to optimise the design of the entrances on tunnel thrusters. This:
The key to optimising thruster energy efficiency, and therefore reducing emissions, is to take a holistic view when specifying them. It is important to avoid simply specifying thrusters in terms of the required power output, as this ignores the following critical factors:
Adopting future fuels is a must if the ferry industry is to hit its decarbonisation targets. The challenge is that, for many future fuels, the infrastructure and availability are still maturing. By opting for flexible, multi-fuel engine technology you gain the flexibility to take the first steps towards decarbonisation with a transition fuel such as LNG. You can then progress through drop-in and fuel-blend strategies towards renewable zero-carbon fuels.
Let’s look at the future-fuel menu currently on offer for the ferry industry.
By opting for flexible, multi-fuel engine technology you gain the flexibility to take the first steps towards decarbonisation with a transition fuel such as LNG.
Retrofitting engines and fuel systems to use low-carbon fuels keeps vessels compliant for longer and offers immediate reductions in greenhouse gas emissions. Engaging a single partner rather than multiple vendors to integrate and supply systems and components will make installation and ongoing maintenance simpler and more effective.
Hybrid and fully electric operations are both making inroads in the ferry industry. At the larger end of the scale hybridisation is becoming the norm for newbuild RoPax vessels. Almost all newbuilds today include hybrid propulsion, and some installations include battery power capacities as large as 5–10 MWh. At the smaller end, fully electric ferries are a common sight in countries like Norway.
Designing a hybrid ferry is not as simple as dropping a battery into your existing design. You need to consider the whole propulsion train setup and understand how to manage the complex interactions between power producers and consumers. This is where expert help from a knowledgeable partner really pays off.
A hybrid solution enables fuel savings by optimising propulsion efficiency – something that will become even more relevant as more expensive low and zero-carbon fuels come into play. With a hybrid solution you:
RoPax ferries operating on longer routes and at constant speeds can use a power take-off/power take-in solution with a shaft generator. This provides electrical power for onboard systems, reducing fuel consumption and helping the engines to run close to their optimal design point.
The core of a hybrid system is not the engine or even the battery, but the energy management system (EMS). With an intelligent EMS you can optimise energy flows under different operational modes between the different power producers for maximum efficiency. This means you get the right amount of power from the right source at the right time. If your hybrid system is well-designed, your vessel’s engines should run at a stable, optimal load and waves and other external forces should not create peaks.
A hybrid solution enables fuel savings by optimising propulsion efficiency – something that will become even more relevant as more expensive low and zero-carbon fuels come into play.
If you want to make big, immediate gains in energy efficiency and fuel savings, energy saving technologies and power limitation are a cost-effective and relatively easy way to do so. But choosing the right combination of solutions is critical. Power limitation might help you comply with EEXI, but with strict schedules to stick to it might not be an option. Plus, in the later stages of CII you might need to add other measures to remain compliant.
Let’s look at the options on the table.
Well-maintained engines and other onboard equipment are the starting point for fuel efficiency. The best way to achieve this is with a comprehensive, tailored service agreement. This will help cut fuel consumption and emissions by ensuring that your vessel’s engines run as efficiently as possible throughout its lifecycle.
More advanced agreements can include dynamic maintenance planning, where maintenance is scheduled and performed based on the actual condition of the engine and main components rather than on a fixed schedule based on running hours. This can extend the time between overhauls, increasing uptime and reducing costs while giving you the flexibility to perform major maintenance with minimum disturbance to your operations. You should look for a provider who can tailored the scope of your agreement according to your needs.
To help you get your decarbonisation strategy right first time, there’s Wärtsilä Decarbonisation Services. The service can help you identify the right decarbonisation path for your ferry business with a simple three-step approach:
With dramatically different ship sizes, configurations and operating profiles, the ferry segment requires a wide variety of approaches to decarbonisation. The challenge lies in selecting and employing the right solutions and technologies efficiently, economically and at the right time.
Want to know how your ferry operations can set course for net zero? Get insight and practical guidance in our white paper: The Route to Profitable Decarbonisation