Wind power, which for centuries was the primary means of propelling ships, is returning to modern commercial shipping with the help of technology. Tankers, bulk carriers and other types of commercial vessels are being fitted with systems that harness wind energy, reducing fuel consumption and emissions.
According to the International Windship Association (IWSA), more than 100 large commercial ships had such systems in June 2026, compared with just 21 in May 2022. That is an almost fivefold increase in four years, reflecting growing interest across the shipping industry.
The ships have a combined carrying capacity of more than 5 million tonnes and are fitted with more than 230 individual wind propulsion systems. IWSA data show that their use helps avoid more than 100,000 tonnes of carbon dioxide equivalent emissions a year.
How wind propulsion works
Wind-Assisted Propulsion Systems, known as Wind-Assisted Propulsion Systems (WAPS), use various technologies to help propel a ship. The basic principle is that the wind provides some of the force needed to move the vessel, reducing the power required from the main engine and, in turn, fuel consumption.
One of the best-known technologies is the Flettner rotor: a large vertical cylinder mounted on deck and spun by electric motors. As the wind flows around the rotating cylinders, it creates an aerodynamic force known as the Magnus effect, which can help propel the ship under suitable conditions.
Another option is rigid sails, which resemble large vertical aircraft wings. Their angle is adjusted to the wind direction to generate a force that helps move the ship. Special sails fitted with air-suction systems are also used to improve their aerodynamic performance.
Computers and automated control systems play a key role. They adjust how the equipment operates in response to wind speed and direction, aiming to maximise performance without necessarily requiring additional crew.
The technology’s effectiveness depends on weather conditions, the ship’s speed and course, and the type of system installed. As a result, fuel savings vary from one voyage to another.
Fuel savings of up to 25%
The main benefit of wind propulsion is lower fuel costs, one of the shipping industry’s largest operating expenses.
According to Norwegian classification society DNV, shipowners and ship management companies have reported fuel savings of between 4.5% and 9% from using WAPS. Under more favourable conditions, potential savings can reach as much as 25% on existing ships.
Even greater benefits may be possible on newbuilds designed from the outset to harness wind energy. In all cases, results are affected by wind speed and direction, the ship’s speed, the route and the system’s technical specifications.
Digital route planning using weather forecasting systems is an important tool for maximising savings. This enables operators to choose routes that make the best possible use of available winds.
Which ships are leading the way
Tankers and bulk carriers are at the forefront of adopting the new systems, according to IWSA data.
The types of ships fitted with wind propulsion systems include:
37 tankers.
24 bulk carriers (bulk carriers), which transport commodities such as iron ore, coal and grain.
24 vehicle carriers and passenger/vehicle ferries.
19 general cargo ships.
Adoption of the technology is not limited to newbuilds. Many of the systems can also be installed on ships already in service, broadening the options available to shipping companies.
Target: 200 ships within the next 12 months
The IWSA expects the market to continue growing rapidly. The association’s secretary general, Gavin Allwright, has noted that testing the systems in real-world conditions and independently verifying their performance are building shipowners’ confidence.
In an estimate made in June 2026, the number of large commercial ships fitted with wind propulsion systems could reach about 200 within the next 12 months.
The industry has also set a long-term goal of extending the technology to 1,000 ships or more.
This prospect is linked both to the need to curb fuel costs and to efforts to reduce greenhouse gas emissions. Despite the technological challenges and reliance on weather conditions, wind is gradually reclaiming its place in modern shipping, combining a traditional means of propulsion with the capabilities of modern engineering and digital systems.