Wärtsilä HY

Market leading hybrid power systems

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Hybrid Solutions

The Wärtsilä hybrid/battery systems "Wärtsilä HY" and its integration with conventional diesel - or dual fuel engine gensets offers significant efficiency improvement by running the engine on optimal load and absorbing many of the load fluctuations through batteries. By increasing the power redundancy, the system allows the engine to operate closer to its optimum design point where it has the highest efficiency and least emissions. This will result in reduced maintenance needs and increased systems performance. Rapid response from the battery system is also among the benefits offered.

The Wärtsilä hybrid/battery systems are suitable for applications in a variety of segments, including offshore vessels, tugs, ferries, and coastal vessels, buildings as well as for retrofits of existing installations.

Wärtsilä HY overview

    Key Benefits 

    • Guaranteed module performance
    • Instant load taking capability
    • No visible smoke under all normal conditions
    • Green mode (zero emissions)
    • Optimized plant dimensioning
    • Built-in redundancy
    • Reduced maintenance (less cylinder-hours, reduced stress to the components)
    • Increased efficiency (lower fuel consumption, fewer emissions)
    • Possible future upgrades (EMS fine-tuning / increased battery capacity)
    • Ship type optimized design and specific application tuning
    • Wärtsilä as the single supplier

    Technical data

    In order to match the specific demands of different market segments, Wärtsilä HY comes in highly customizable forms.

    The standard mechanically driven configuration includes:

    • Main engine with on/off clutch
    • PTO/PTI on the gearbox (or in-line shaft generator/motor)
    • Energy storage system
    • DC link and power drives
    • Energy Management System

    The standard electrically driven configuration includes:

    • Generating set
    • Energy storage system
    • DC link and power drives
    • Energy Management System


    The Wärtsilä HY will have dedicated versions for each category of vessels. The first versions being made available will be designed for tugs and medium sized ferries. This is the first new product of this type launch where each individual version is dedicated to a specific market to secure an optimal fit to the requirements of each application.

    The Wärtsilä hybrid system is designed and integrated to optimise the overall operation of the vessel. The system ensures fuel savings and reduced maintenance costs, in addition to substantial reductions in emissions.

    Wärtsilä HY solutions

    New build and retrofit solutions to meet vessel operating profile


      The Wärtsilä HY Module for Bulkers is a compact containerised solution that can cut a vessel’s emissions by up to 4% by optimising onboard power production, consumption and management, supporting EEXI compliance and securing a more profitable future. 

      The HY Module for Bulkers combines an energy storage system and integrates additional energy sources such as energy from solar panels with Wärtsilä’s highly sophisticated Energy Management System (EMS) to deliver auxiliary power to the grid. The containerised solution can be placed on deck to save space and can be installed without the need for drydocking.

      Cruise & Yacht

      Wärtsilä HY for Cruise is the solution that connects the world of today with a ‘zero emissions’ future, offering a new way of powering cruise ships.

      The best aspects of different technologies are combined into a unique integrated product that goes beyond the standard vessel’s power production concept.

      Wärtsilä HY for Cruise is the best friend of all emission sensible areas. Thanks to its reduced smoke operations it is the perfect product for cruise needs, from arctic to equator.

      Even zero emission areas are not a limit. Further, the capability to combine different fuels with different energy transformers and storage system is the key element in creating an eco-friendly vessel with enhanced safety, flexibility and versatility.

      It is scalable to any size of vessel, from small yachts to huge cruise vessels, and can be applied to any Wärtsilä engine size and type, covering a broad power range, up to 100 MW and beyond.


      Taking the advantage of combining and optimizing Wärtsilä HY with the extensive Wärtsilä propulsion portfolio, ferry operators can deliver less environmental impact on the port communities and better passenger comfort. Engine noise, vibration, and smoke are all drastically reduced. They can even be entirely eliminated when in port and during shorter sailing routes because the engines can be completely switched off, still keeping excellent maneuvering performance, with huge fuel saving and less required maintenance.

      The zero emission operation, or green mode, is illustrated below for a ferry equipped with diesel mechanic propulsion, two main propellers, bow thrusters and rapid wireless charging of the Energy Storage System (ESS). The estimated payback time for this configuration is about 4 years, depending on fuel and shore power price.

      Hybrid propulsion is part of the future for RoRo/RoPax ferries

      DOWNLOAD Whitepaper

      Business White Paper - Hybrid propulsion is part of the future for RoPax ferries

      The first hybrid RoRo


      Dredgers can derive significant benefits from Wärtsilä HY, thanks to the increased load taking capability and enhanced reliability, thus providing smooth and continuous operations, avoiding high stress condition for mechanical components. The EMS ensures instant load taking and dynamic power demand, and can be further tuned for performance optimizing to meet different dredging operation requirements, depending on the assignment. Compared to a conventional machinery arrangement, operating costs are lowered as the EMS control provides an increased energy efficiency with engines running at optimal and stable load for better fuel consumption. The lowered fuel consumption, less total engine cylinders and engine running hours results in a superior payback time of 1-3 years depending on the dredgers operations. Below figure illustrate the hybrid operation mode of a trailing suction hopper dredger as example. 


      The key enablers for offshore vessels are reliable and flexible operations. Wärtsilä HY for OFFSHORE offers lower fuel consumption especially in dynamic positioning operations, while longer time between overhauls enable a higher rate of vessel utilization. ESS redundancy increases even more the safety levels of offshore operations. 


      The first customers to benefit from the Wärtsilä HY revolution have been tug owners, recognizing the huge advantages this innovative product offers. Cold start up, smokeless operations, the start and stop feature, and the extra power boost elevate tugs to the next level.

      With this new set up, any tug is able to assist ships, regardless of the conditions, with unprecedented operation effectiveness and environmental performance.

      The variety of missions and skills required to crew a tug means it is a demanding and critical role in ports and coastal areas across the globe. To meet these demands we know a tug needs to be reliable, efficient, and above all safe in every operating profile.

      Our systems and solutions fit tugs from 700kw to the largest in the market. With the need to have the flexibility and sustainable solutions we are able to deliver highly efficient conventional or LNG and hybrid tug vessels with complete power and propulsion systems, electrical and automation technology, a range of environmental solutions, and much more, all of which are tailored to suit your operational needs. Our smart marine solutions are also bringing new technologies to increase efficiency and reduce costs in a safety-conscious environment from smart navigation between missions to situational awareness for safety Wärtsilä is the partner you can rely on to pull its weight.

      Download BWP HY TUG propulsion system

      Business White Paper: Wärtsilä HY TUG propulsion system

      With regulatory compliance becoming more and more of a global issue, Wärtsilä is launching new propulsion systems for tugs emphasising environmental sustainability. The systems have been developed utilising the company’s strong competences in hybrid propulsion technology. Since tugs typically operate in or close to harbours, they are particularly affected by environmental considerations, and the need to reduce emissions is an increasing concern for tug owners and operators.

      Download Business White Paper

      Recent webinars

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      Our field service capabilities continuously evolve to meet the needs of the increasingly complex nature of the systems used by our customers. We can take full responsibility for service quality regardless of where an asset may be in the world, helping you to realize significant savings in operating costs and enabling you to focus on your core business.

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      Customer stories

      • Harvey Gulf International Marine

        Wärtsilä HY hybrid upgrade has helped make Harvey Gulf International Marine’s operations significantly more fuel efficient and environmentally friendly.

        Read more
      • Maersk Minder

        Wärtsilä HY hybrid upgrade cuts fuel consumption and carbon emissions onboard the Maersk Minder anchor handling tug supply vessel.

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      • Rawabi goes hybrid

        A hybrid retrofit with engines and batteries cut emissions and operating costs and optimised engine operation for the Rawabi 324 anchor handling vessel.

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      • Finnlines’ three new RoRo vessels

        New RoRo vessels enjoy improved efficiency and sustainability with Wärtsilä’s electric hybrid propulsion and energy management and optimisation systems.

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        Wärtsilä Hybrid upgrade brings significant fuel savings for offshore vessel

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        MF Folgefonn was retrofitted into a full scale hybrid and plug-in hybrid ferry

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      • Viking Supply

        Hybrid upgrade for Viking Supply Ships sharpens competitive edge of LNG-powered PSVs

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        Wärtsilä HY solution for operational flexibility combined with notable environmental benefits

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        The Viking Lady platform supply vessel embodies a number of groundbreaking, energy efficient, and emissions reducing technologies.

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