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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

Tuesday, May 16, 2023

PrimeServ SCR Retrofit Makes Cruise Ship Tier III-Compatible

Ultra-compact Selective Catalytic Reduction along with TCA 66 turbochargers help vessel meet exacting Norwegian emission standards

MAN Energy Solutions’ after-sales division, MAN PrimeServ, has completed a retrofit aboard the ‘Ambience’, a vessel belonging to Ambassador Cruise lines, managed by Bernhard Schulte Cruise Services. The scope of the project covered the installation of SCR (Selective Catalytic Reduction) systems, while two of the ship’s four MAN 8L58/64 engines replaced their NA57/T turbochargers with modern MAN TCA 66 units.

The order came about when Ambassador overtook the Ambience with the intention of offering cruises in the key Norwegian Heritage Fjord market with its exacting Tier III emission standards.

Olaf Gunia, Head of PrimeServ Hamburg, said: “This retrofit really establishes Ambassador’s green credentials within the cruise segment and the SCR solution is performing well with a NOx removal rate of 93%. Increasingly, we are receiving similar requests from cruise and ferry operations that wish to become sustainable without the need for mandated industry legislation.”

Bernd Siebert, Head of Retrofits & Upgrades, MAN PrimeServ, said: “This entire project proved challenging owing to – among other factors – the long cold lay-up of the ship due to the covid-19 pandemic, and the tight timeframe for completion. Happily, our work on the Ambience has optimised the interaction between the newly installed SCR system, turbochargers and engines and the vessel is now Tier III-compatible and fit for service in one of the globe’s most pristine, natural environments.”

SCR technical considerations


MAN’s SCR system is the greenest solution available on the market with the highest operational readiness and safety. The SCR will be available from just 15% engine load, enabling clean operation, also during slow-sailing in the fjords as well as close to port and populated areas.

The fully modular SCR solution has also been fully integrated into the Ambience’s engine-control set-up. With its closed-loop system and a weather station that uses environmental data, the NOx-reduction rate is maximised and ammonia-slip minimised to just 10 ppm, comparable to that of a car. Low ammonia slip is not just good because ammonia is a greenhouse gas and affects the climate, but also because it reduces urea consumption enabling the urea-tank size to be minimised.




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.