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Retrofitting can reduce CO2 emissions significantly

MAN Energy Solutions is implementing retrofitting technology to convert ship and power plant engines into future-ready machines capable of running on synthetic fuels – gaseous or liquid. Upgrade solutions and advanced customized retrofits by MAN PrimeServ open a world of options. They help you optimize reliability, efficiency, and performance; they lower maintenance expenses and add operational flexibility. More importantly, they enable you to comply with increasing environmental regulations. Retrofitting an engine extends the life cycle substantially, thus abating up to 97% of CO2 compared to e.g., building a new ship.

Our retrofit solutions reduce GHG emissions by up to 20 percent
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Potential in savings of CO2 emissions
Engines have a potential for a future fuel retrofit

Keep your engines, systems, and equipment compliant and competitive 

Cargo ships and power plants are long-term investments. Retrofitted and modernized with high-value MAN Energy Solutions’ products, they become more sustainable, can continue to be used for decades, and are an attractive investment proposition.

Retrofits play an important role in the energy transition and are crucial for achieving a green fleet of ships or power plants that help to meet the targets of the Paris Agreement.

A recent study indicates that around 1,900 two-stroke and 1,800 four-stroke marine and power plant engines have the potential for a future fuels retrofit.

Maximize savings with future fuels through cutting-edge retrofit solutions 

Switching between different fuels is made easy with MAN dual fuel engines, as they are highly versatile and capable of utilizing both liquid and gaseous fuels. This flexibility empowers you to transition between fuels at your convenience, whether driven by factors like fuel costs or regulatory requirements. What's more, these engines can seamlessly switch between fuels even while operating, all without compromising engine performance. Should you wish to convert single fuel engines to dual fuel, please note that such a transformation may necessitate adjustments to your fuel supply infrastructure. Our team of MAN PrimeServ fuel experts is readily available to provide guidance and discuss the various possibilities. 

Converting existing engines to dual-fuel operation is crucial to decarbonize shipping because it’s a powerful measure that can be implemented quickly. This is an essential first step, as all such dual-fuel engines can also be enabled to operate on a range of carbon-neutral synthetic fuels, including synthetic natural gas (SNG), green ammonia and methanol. And from an economic perspective, retrofitting is much more efficient than installing a new engine or building a new ship 

Unlocking efficiency and cost savings 

Our retrofit solutions, upgrades, and services optimize investment returns. They boost efficiency as well as performance, and reduce maintenance, fuel, and lube oil costs. 

Experts in retrofitting and dual-fuel conversions

At MAN Energy Solutions, we have a long-standing experience in retrofitting engines with state-of-the-art technology. We have also pioneered the conversion of large container ships to LNG operation, for example for Hapag-Lloyd, and are currently converting engines on board of a Karadeniz Powership from heavy-fuel-oil to dual-fuel operation.

Finding the perfect fit

Beside methanole, other fuels can also be a solution for your marine application: LNG, bio fuels or amminia. Find your perfect fit now.

News about our retrofit solutions

Thursday, March 21, 2024

MAN 51/60DF Engine Passes 10 Million Operational Hours Milestone

Latest 100 sales within last two years

MAN Energy Solutions has announced that its MAN 51/60DF engine has passed the milestone of 10 million operational hours. The company states that, since its market entry, the dual-fuel engine has proved extremely popular with 310 engines currently in service an increase of almost 100 units since 2022.

The 51/60DF engine, which can run on a wide variety of fuels including natural gas, biogas, bio-fuel, synthetic fuels, distillates and heavy fuel oil, has been in MAN Energy Solutions’ portfolio since 2009. It comes in various power classes from 6.3 to 20.7 MW and is serviced by MAN PrimeServ, MAN Energy Solutions’ after-sales division, on five continents.

Stefan Eefting, Head of MAN PrimeServ Germany, said: “This is a significant milestone that stands testimony to the character of this engine. The 51/60DF has become a fixture in shipping and power-plant operation and stands for absolute reliability – even in high ambient temperatures. Switching between the different fuels happens more or less at the touch of a button and is possible at any point between 0 and 100% load without any loss of power or frequency shift.”

MAN Energy Solutions states that the 51/60DF is extremely reliable in both operation and maintenance. In addition to excellent availability of up to 98%, many of the engine’s core components show remarkably little wear even after extended operation, regardless of whether the engine has been running on heavy fuel oil or gas. Experience to date has also shown that the maintenance intervals achieved have significantly exceeded the expected, planned schedule of 36,000 hours.

Uniquely, MAN Energy Solutions is the only brand to supply all auxiliary system components to its engines. In addition to the MAN turbochargers integrated with MAN engines, customers furthermore receive MAN injection systems, as well as MAN control and automation systems from the one source. Accordingly, all individual systems are optimally matched to one other, meaning that a unique, customised service concept can be offered – a unique selling point for the market.

In terms of fuel, Eefting added: “Fuel flexibility is a must for modern engines. The 51/60DF is already operating on heavy fuel oil, marine diesel and liquid biofuel, biogas, green Synthetic Gas (SNG) and is well proven in numerous installations around the world through its compliance with the ever tougher emission requirements of World Bank and IMO. In the coming years, it will also be capable of operation on other especially green synthetic fuels as methanol and by that contribute to the decarbonisation of the energy and maritime sectors.”


The 51/60DF engine is also available as a retrofit kit for 48/60 engines as part of MAN PrimeServ’s standard retrofit portfolio


  • PR 51.60DF milestone_EN
    PDF, 272 KB English



Nils Søholt

Trade Press Marine

Group Communications & MarktingMAN Energy SolutionsTeglholmsgade 412450 Copenhagen SVDenmark

t +45 33 85 26 69

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Frequently Asked Questions

Can I retrofit older vessels, or are retrofits primarily for newer ships?

Retrofits benefit vessels of all ages, not just newer ones. It extends the operational life of vessels and ensures compliance with evolving industry as well as environmental standards. Retrofit options depend on the vessel's age, condition, and design, but older ships can benefit from retrofits as well.

What are the environmental and regulatory benefits of upgrading to cleaner technologies in marine applications?

Upgrading to cleaner technologies in marine applications provides numerous environmental and regulatory benefits. This includes significant reductions in emissions of air pollutants, compliance with international regulations, improved fuel efficiency, and noise reduction. Moreover, cleaner technologies enhance safety, contribute to long-term sustainability by reducing carbon emissions, and open access to environmentally conscious markets.

What is the expected downtime during a retrofit or upgrade project?

The expected downtime during a retrofit or upgrade project varies significantly based on factors like the project’s size, customization, location, regulatory requirements, and unforeseen issues. Downtime can range from a few weeks to several months. Efficient project planning can help reduce downtime, while unforeseen problems may extend it. The goal is to strike a balance between minimizing downtime and ensuring high-quality and safe work.

Strategic expertise for global sustainability

Apart from retrofit solutions, as an integral component of our future technology portfolio, we also provide enduring core products and digitalization services. With our extensive expertise in these domains, we are mapping out the path towards a sustainable future.