Wärtsilä EnergoFlow

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Wärtsilä EnergoFlow for improved energy efficiency

Vessel owners are facing the twin challenges of ensuring compliance with the IMO’s Energy Efficiency Existing Ship Index (EEXI) and Carbon Intensity Index (CII) measures while also needing to improve operational efficiency in order to remain competitive. Wärtsilä EnergoFlow is an innovative pre-swirl stator that improves a vessel’s propulsive efficiency by creating an optimal inflow for the propeller, reducing both fuel consumption and emissions.

Wärtsilä EnergoFlow creates optimal inflow for the propeller by guiding one side of the stern flow in the opposite direction to the propeller rotation, generating pre-swirl. The solution consists of multiple curved fins and a ring attached to the ship’s hull to prevent the power losses that typically occur in a propeller’s slipstream.

Key benefits

  • Improve fuel efficiency by up to 10% in combination with a new propeller design and Wärtsilä EnergoProFin
  • Reduce NOx and CO2 emissions
  • Take steps towards EEXI compliance through minimum speed reduction
  • Improve vessel CII rating
  • Fast return on investment of one to two years

    Technical info

    Scope of supply

    • System design, supply and class certification
    • Trailing Edge Modification (for fixed pitch propellers)
    • Installation drawings and instructions
    • Design interface with the shipyard or ship designer
    • Supervision by Wärtsilä technicians during installation

    • New, optimised propeller (optional)
    • Scale models of EnergoFlow and/or propeller for tank testing purposes (optional)


    The EnergoFlow system is suitable for a wide range of vessels fitted with either fixed pitch or controllable pitch propellers. The system is easily integrated with these solutions whether they have been originally supplied by Wärtsilä or other manufacturers.

    Articles and whitepaper

    Water whipped up by ship
    19 Sep 2023 · Article
    6 min read
    The top 4 ways to comply with EEXI without slowing down your vessels
    Want to comply with EEXI regulation without reducing your sailing speed? Here...
    11 Jun 2021 · Article
    5 min read
    Wärtsilä’s energy efficiency solutions provide significant savings for Delphis
    Delphis’s ice-classed container ships were fitted with Wärtsilä...
    Grimaldi Ro-Ro ship the Grande Portogallo
    16 Sep 2020 · Article
    3 min read
    Saving the maritime industry, one energy-saving device at a time
    Wärtsilä’s partnership with MARIN and Grimaldi on the LeanShips initiative has...
    Why propulsion efficiency is the name of the game
    14 Mar 2018 · Article
    3 min read
    Why propulsion efficiency is the name of the game!
    By focusing on optimising the lifecycle efficiency of ships, Wärtsilä's role as a full-service...
    Wartsila EnergoFlow boosts propulsion efficiency
    8 Nov 2017 · Article
    4 min read
    Wärtsilä EnergoFlow boosts propulsion efficiency
    Wärtsilä launched its latest energy-saving device for ship engines, a next-generation pre-swirl...
    Wartsila EnergoFlow banner
    White paper
    4 pages
    White paper: Wärtsilä EnergoFlow - Robust and Reliable
    Wärtsilä’s energy efficiency solution, EnergoFlow is a path-breaking solution enabling the...


    22 Feb 2022 · Webinar
    EEXI compliance through Wärtsilä Power Limitation Solutions​
    Power limitation solutions effectively limit engine or shaft power during normal...
    Man working on a propeller
    11 Jun 2020 · Webinar
    Propulsion energy saving technologies
    With the shipping industry facing increased environmental legislation and increasing operational costs,...

    Customer stories

    Discover the benefits others have already gained from Wärtsilä EnergoFlow for improved energy efficiency.

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