Fixed sails or wings


Cargo ship equipped with sails, source: IWSA

Fixed installations on the ship in the form of a flexible sail, rigid sail or turbosail can make use of the wind to replace some of the propulsion power needed. All possibilities have pros and cons and must be chosen to best suit the ship type, trade and size. The savings are highly dependent on the wind conditions in which the ship operates.

Applicability and assumptions


Source: IWSA

These initiatives are only applicable for ships with enough space and therefore not container ships. There is no vessel age restriction for fixed sails or wings. Stability due to the high placement of additional weight and force from the sails is not assumed to be an issue for the ships. Prices are based on ships not needing changes in design in order to fit the masts. The masts and sails are assumed to have a potential of providing about 710 kW of power per installed mast which will result in a forward thrust and reduce the power needed from the main engine. The effect of each mast is assumed to improve to 1,200 kW in 2020 and keep constant after that. The effect of each mast will vary with the prevailing wind and therefore will not be effective most of the time. It is assumed that the sails only will be operational 15% of the time. The effect and applicability of this measure is also dependent on operating speed (most useful in the lower speed range).

Cost of implementation

The price per mast (including installation) is expected to decrease dependent on how many masts are installed on board. Thus, the capital cost involved will range from $170,000 to $300,000 (USD) per mast installed.

Reduction potential

The reduction potential is dependent on vessel size, segment, operation profile and trading areas. The likely reduction potential is estimated to be in the range of 1% to 10% on main engine fuel consumption.

Other References

  1. Air pollution and energy efficiency / IMO energy efficiency appraisal tool

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