Wärtsilä Ammonia engine
Wärtsilä AmmoniaPac

A complete ammonia fuel supply system for ships, designed to support safe onboard storage, processing and supply of ammonia fuel. Explore how AmmoniaPac can support ammonia-fuelled propulsion and power generation in newbuild and retrofit projects.

Wärtsilä AmmoniaPac – fuel supply system for ammonia-fuelled ships

Wärtsilä AmmoniaPac is a complete fuel supply system for ammonia-fuelled ships, designed to support the safe storage, processing and fuel supply of ammonia fuel onboard. It includes bunkering station skids, storage tanks, main process equipment, and control and monitoring systems that provide stable and reliable gas flow to the engines.

As part of the Wärtsilä ammonia-fuelled power solution, AmmoniaPac supports vessels using ammonia for propulsion and onboard power generation. The system also includes an integrated Ammonia Release Mitigation System, ARMS, to prevent ammonia release from the process system. 

At a glance

What it is:
Wärtsilä AmmoniaPac is a complete ammonia fuel supply system for ships, covering bunkering, onboard storage, fuel processing, control and monitoring, and delivery of ammonia fuel to the engines.

Why it matters:
Ammonia has the potential to be CO2-free with produced using renewable energy and releases no sulphur or particulates when combusted.

How it works:
The system safely bunkers and stores liquid ammonia, processes it onboard, and provides stable and reliable gas flow to Wärtsilä ammonia engines. It uses automation, control and monitoring, and ARMS to support safe fuel handling.

Where it applies:
Wärtsilä AmmoniaPac is suitable for ammonia-fuelled vessels using ammonia for propulsion and power generation, including newbuild projects and retrofit projects subject to vessel-specific requirements and project evaluation.

Why this matters now

Ammonia is becoming one of the marine fuel options ship owners and operators are evaluating as they plan how to reduce greenhouse gas emissions from future vessels and existing fleets.

For technical and sustainability teams, the question is not only whether ammonia can reduce emissions. It is how ammonia can be handled safely and reliably onboard. Wärtsilä AmmoniaPac is designed to address this fuel-handling challenge as part of the ammonia-fuelled vessel system. It combines storage, processing, automation, control and monitoring, and ammonia release mitigation to support controlled onboard operations.

What this solution delivers for you

Wärtsilä AmmoniaPac helps you move from general ammonia-fuel interest to a practical vessel concept by providing the fuel supply system needed to store, handle and deliver ammonia onboard. It is designed for ammonia-fuelled ships and supports both propulsion and onboard power generation applications.

The solution is tailored and vessel optimised to meet operational and regulatory needs, and it can be configured for semi refrigerated and fully refrigerated ammonia using Type-C single shell tanks, depending on the available ammonia and regulatory requirements. 

When AmmoniaPac is delivered as part of the complete Wärtsilä ammonia solution, it is integrated with Wärtsilä ammonia engines, helping to maximise safety in the engine room and fuel handling spaces. For ship owners and technical teams, this means the fuel supply system can be evaluated as part of the wider vessel design, conversion scope and safety case instead of as an isolated component.

How it works

Wärtsilä AmmoniaPac manages the ammonia fuel pathway from bunkering to storage, processing and supply to the engines. The fully automated system includes bunkering station skids, storage tanks and main process equipment, supported by a control and monitoring system. This allows the liquid ammonia to be bunkered and stored safely, then supplied as a stable and reliable gas flow to the engines.

The system design is based on experience in developing Wärtsilä’s LNGPac solution, and it has been designed to comply with evolving class rules for ammonia. It is fully compatible with the Wärtsilä 25 ammonia engine and can adapt to future requirements on fuel supply.

The safety concept includes integrated automation, control and monitoring, and ARMS, which prevents ammonia release from the process system. In addition, the system is designed so that ammonia emissions from normal operations are eliminated.

AmmoniaPac overview

Where it applies

Wärtsilä AmmoniaPac is suitable for:

  • Ammonia-fuelled ships using ammonia for propulsion.
  • Ammonia-fuelled ships using ammonia for onboard power generation.
  • Newbuild projects where ammonia-fuel capability is being evaluated as part of the vessel concept.
  • Retrofit projects, subject to vessel-specific requirements and project evaluation.
  • Vessel designs requiring semi refrigerated or fully refrigerated ammonia storage using Type-C single shell tanks.
  • Above-deck or below-deck arrangements, supported by an integrated airlock and double manhole enclosure.
  • Single-lobe, bi-lobe and prismatic tank arrangements, with optimised tank connection space designs to maximise onboard space utilisation.

Delivery and implementation

Wärtsilä AmmoniaPac is delivered as a vessel-specific ammonia fuel supply system rather than as a generic standalone product. The system design can be tailored and optimised to meet the vessel’s operational and regulatory needs, including the selected ammonia storage arrangement, onboard location, tank configuration and fuel supply requirements.

In practice, the scope can include the bunkering station skids, storage tanks, main process equipment, control and monitoring system, and integrated ARMS. The system can be configured for refrigerated or fully pressurised ammonia and can support above-deck or below-deck locations, depending on the vessel design and project requirements.

For projects where boil-off gas management is an important consideration, a subcooler unit can be included. This way, there is unlimited holding time and worry-free tank BOG management.

For ammonia-fuelled vessel projects, delivery and implementation should also be considered as part of the wider safety and integration work. Wärtsilä can offer a complete ammonia solution, developed with a holistic approach involving customers, classification societies and flag states.

Proof and references

If you are evaluating ammonia fuel supply for a vessel project, it helps to see where the technology is already being applied and how Wärtsilä is supporting ammonia-fuelled vessel development.

Skarv Shipping Solutions new cargo vessel with the Wärtsilä 25 Ammonia solution
~90% lower greenhouse gas emissions with green ammonia

Skarv Shipping Solutions selected the Wärtsilä 25 Ammonia solution, including the AmmoniaPac fuel supply system, for a new short-sea cargo vessel. When operating on green ammonia, the solution is expected to reduce total greenhouse gas emissions by at least 90% compared to an equivalent diesel-powered vessel.

Industry developments

The transition to ammonia as a marine fuel is being shaped by new vessel projects, technology milestones and industry collaboration. Explore Wärtsilä announcements related to ammonia-powered vessels, fuel supply systems and maritime decarbonisation initiatives. 

Frequently asked questions

What is Wärtsilä AmmoniaPac?

Wärtsilä AmmoniaPac is a complete fuel supply system for ammonia-fuelled ships. It includes bunkering station skids, storage tanks, main process equipment, and control and monitoring systems for storing, processing and supplying ammonia fuel onboard. 

Can Wärtsilä AmmoniaPac be used for both propulsion and power generation?

Yes. Wärtsilä AmmoniaPac supports ammonia fuel supply for marine propulsion and onboard power generation applications, including use with the Wärtsilä 25 engine-based ammonia solution.

Is Wärtsilä AmmoniaPac suitable for retrofit projects?

Wärtsilä AmmoniaPac can support both newbuild and retrofit projects, subject to vessel-specific requirements and project evaluation. For retrofit projects, the system should be assessed against the vessel’s available space, tank arrangement, safety requirements and overall ammonia conversion concept.

How does Wärtsilä AmmoniaPac support safe ammonia handling onboard?

Wärtsilä AmmoniaPac supports safe ammonia handling by managing bunkering, storage, processing and fuel supply in a controlled way. The system includes automation, control and monitoring, and an integrated Ammonia Release Mitigation System, ARMS, to prevent ammonia release from the process system.

Why consider ammonia as a marine fuel?

Ammonia is being considered because it has the potential to support major reductions in vessel carbon emissions, especially when produced as green ammonia. The current AmmoniaPac page states that adopting green ammonia can reduce a vessel’s carbon footprint by around 70%, while sulphur and particulate emissions are zero when ammonia is combusted.

Continue exploring ammonia solutions

Whether you are exploring ammonia as a future fuel option, assessing safety implications, or building a business case for vessel decarbonisation, these resources can help you deepen your understanding of ammonia-powered shipping.

Ammonia as marine fuel? Benefits, challenges, and smart adoption: Explore key aspects of ammonia as a marine fuel, including its potential role in shipping decarbonisation.

Expert advice: how to deal safely with ammonia on board ships: Learn more about the practical considerations of handling ammonia onboard and the measures needed to support safe vessel operations.

Excited about ammonia as marine fuel? 6 things you need to know: Get an introduction to some of the topics commonly discussed when evaluating ammonia as a marine fuel option.

Future fuels A to Z: Explore a range of fuel and energy pathways that are being considered as part of shipping's transition toward lower-emission operations.

If ammonia is part of your vessel strategy, start with the fuel supply system.

The safe and reliable use of ammonia onboard depends on more than fuel choice. Contact Wärtsilä to discuss how AmmoniaPac could support your newbuild or retrofit project as part of an ammonia-fuelled vessel concept.

Wärtsilä Marine. Let's connect.

The contents of this page have been written with the help of AI. A Wärtsilä expert has checked and verified these contents.