Wärtsilä EnergoFlow is a proven marine energy saving solution that improves ship fuel efficiency by optimising propeller inflow. It reduces fuel consumption, emissions, and operating costs while supporting compliance with IMO regulations. Designed for both retrofits and newbuild vessels, it delivers measurable efficiency gains with fast payback.
A hydrodynamic energy saving device – a pre-swirl stator – installed at the stern to optimise propeller inflow and propulsion efficiency.
Why it matters:
How it works:
EnergoFlow creates pre-swirl in the water flow entering the propeller, reducing energy losses and improving propeller efficiency – so the engine works less to maintain the same speed.
Where it applies:
Shipowners and operators face mounting pressure to reduce fuel consumption while meeting tightening emissions requirements – EEXI, CII, and beyond. At the same time, volatile fuel prices continue to squeeze operating margins.
Improving propulsion efficiency is no longer a nice-to-have. It is a direct lever for protecting profitability, meeting regulatory thresholds, and maintaining vessel charter attractiveness.
EnergoFlow addresses these pressures through practical, proven hydrodynamic optimisation – without major operational disruption.
EnergoFlow lowers the power required to maintain vessel speed, directly improving fuel economy and protecting margins in a volatile cost environment.
A low-risk upgrade path with quantifiable returns – both operational and financial.
Wärtsilä EnergoFlow is a pre-swirl stator consisting of curved fins mounted on the ship's stern, often connected by a ring structure. The fins guide incoming water flow to rotate in the opposite direction of the propeller – creating a more uniform and efficient inflow.
This reduces energy losses in the propeller slipstream, improves blade loading, and lowers the engine power needed to achieve the same vessel speed.
The connecting ring further reduces vortex losses and distributes structural loads, improving durability in demanding sea conditions.
Suitable for shipowners and fleet managers focused on fuel reduction, EEXI compliance, and CII improvement.
EnergoFlow is an engineered solution tailored to each vessel. Delivery typically includes system design, hydrodynamic optimisation, class certification, and installation support.
For retrofits, Wärtsilä provides full design integration with the existing vessel – including trailing edge adjustments for fixed pitch propellers where required. On-site supervision ensures correct implementation.
EnergoFlow can also be combined with optimised propeller upgrades and other energy saving technologies to maximise performance gains.
Each design goes through extensive load analysis, covering both peak loads and fatigue lifetime to ensure the stator performs reliably over the vessel's operating life.
Wärtsilä has developed a dedicated EnergoFlow configuration for twin-skeg LNG carriers – demonstrating how vessel-specific optimisation unlocks measurable savings.
~2.5% fuel consumption reduction
~€350k–420k annual savings per vessel depending on EU exposure
Payback period below 1 year
Reducing fuel consumption and improving your vessel’s CII rating doesn’t require compromise. With Wärtsilä EnergoFlow, you gain a proven, practical upgrade that delivers measurable results - quickly and reliably.
Talk to our experts to explore how it fits your fleet.
