Sustainable fuels paper

Sustainable fuels article series

Future-proofing flexible Wärtsilä engine power plants for decarbonised energy systems

As established, modern and flexible engine power plants are an ideal solution as balancing power, due to their flexibility in both fuels and operation profiles. This is needed as batteries alone cannot fulfill the balancing need for fluctuating renewable power sources. Flexible capacity must be ready to start quickly at any time and capable of quickly ramping up and down an unlimited number of times per day. Current Wärtsilä engine power plants can connect to the grid in 30 seconds and reach full load in just two minutes. With such fast ramp ups less fuel is consumed during start up and thus set-up emissions are lower.

There is benefits of having multiple medium-sized power plant units when dynamic power output levels are required. By switching units off and running the remaining units at highest efficiencies, overall fuel consumption and CO2 emissions are minimised.

Current Wärtsilä gas engine power plants can use up to 25 vol% hydrogen blends in natural gas and there is ongoing development for pure hydrogen and other P2X fuels. A fuel change can require changing the combustion parameters of the engine and therefore potentially results in changed output. With hydrogen blends it is expected that there is no impact on component lifetime nor frequency of maintenance. Selection and testing of new materials and components are ongoing for the various P2X fuels concepts and the life cycle aspects are a vital part of that development.

Current Wärtsilä gas engine power plants can use up to 25 vol% hydrogen blends in natural gas and we are developing a concept for pure hydrogen operations to be launched in 2025.

Wärtsilä is working on future fuel development according to its initial timetable

There are good synergies between the Wärtsilä Energy and Marine business units in fuel development needs and Wärtsilä is testing and validating engines and new solutions for both markets.

Wärtsilä continues developing hydrogen power plant solutions and will launch a power plant design for hydrogen blends in 2022 and a concept for pure hydrogen in 2025.

Sustainable fuel capabilities of the Wärtsilä engine types

Sustainable fuel capabilities of Wärtsilä engines

Ready solution           

Industrialisation needed         

Research ongoing

Wärtsilä has proven track record in conversions

Power producers have always been concerned about their existing fleets becoming stranded assets due to changing market conditions and new fuels becoming available. The transition from carbon-intensive fuels e.g. coal or HFO to natural gas is a significant improvement step. Decarbonisation can already now be further enhanced utilising blends or pure biofuels. If the conversion is made to dual-fuel engines they can use an even wider range of fuels. For dual-fuel engines, a switch between liquid fuel and gas can effortlessly be made when the new fuel becomes available locally.

Conversion is generally a more economically viable way to implement future fuels than making greenfield investments. Wärtsilä will have conversion packages for hydrogen engine power plants and also have the capability to develop ammonia and methanol conversions when required. The current understanding is that the bulk of the engine will remain unchanged, while the fuel supply and control systems will be impacted.

Wärtsilä has an extensive track record of optimisations and conversions to new fuels for existing assets – over 100 engines worldwide are converted from HFO to run on gas. The main drivers for conversions from liquid fuels to gas have been the reduction of operational costs, local and GHG emissions. Local NOx emissions are reduced by 80-90%, and as natural gas contains almost no sulphur or ash, SOx and PM emissions are very low. The GHG emissions are reduced by 10-15%. By converting from HFO to natural gas, power producers can become more competitive and meet new emissions regulations – ensuring that they can continue to operate and get a return on their investment despite a changing business environment.

Key factors impacting the switch to sustainable fuels for engine power plants

Financing – many new rules need to be followed to ensure that the investment is sustainable

Fuel availability has to be secured on site depending on scale, mode of supply and local regulations

CapEx – conversion packages may include new and more expensive solutions compared to the current mature solutions such as safety, fuel supply and control systems, storage and emissions control

OpEx is higher due to novel and increased operational complexity

Engine conversion to gas

Wärtsilä collaborates with customers, suppliers and research institutions

Wärtsilä has continuous discussions with customers to utilise sustainable fuels in greenfield projects - or to evaluate fuel blends or fuel conversions for existing assets. Wärtsilä is committed to support its customers to move forward on their path to decarbonisation.

As part of the strong green hydrogen boom Wärtsilä is planning several hydrogen projects with partners and customers ranging from utilising hydrogen blends in existing assets at customers to a P2X2P plant in collaboration with partners.

For the maritime sector, Wärtsilä is currently installing and commissioning the first ammonia pilot dual-fuel engine in Norway. Wärtsilä’s methanol-fuelled engines have powered the Stena Germanica ferry since 2015 and in 2021 the methanol engine solution including fuel storage and supply system (MethanolPac) has been launched.

Sustainable fuels ecosystem

Wärtsilä has invested heavily in its development and production facilities during the last years. In June 2022, the new technology centre, Wärtsilä Sustainable Technology Hub, was opened in Vaasa, Finland. Together with both internal and external partners, the Wärtsilä Sustainable Technology Hub is a collaboration ecosystem both on local and global level. It connects companies, start-ups, organisations and academia in developing future sustainable societies.

Fuel testing and engine development will continue throughout the coming years. Wärtsilä is there to enable the transition to a decarbonised future with innovations in fuel flexible technology and decarbonisation services.


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