In the world’s oceans, the international shipping sector is responsible for emitting carbon dioxide (CO₂) equivalent to the entire country of Germany. To stay on track with the Paris Agreement’s 1.5°C goal, a 34% reduction in shipping emissions by 2030 is necessary. However, as low-carbon fuel pipelines won’t be readily available until the 2030s, there is a need for short-term solutions.
One promising solution is the use of sails. Although not the billowing canvases of the past, modern sail technologies can harness renewable wind energy to complement a ship’s engine propulsion. Two designs gaining attention in the shipping industry are Flettner rotors, which spin to generate propulsion, and “wingsails,” inspired by yacht racing designs.
Wind propulsion reduces fuel consumption and greenhouse gas emissions. Combining sails with optimized routes plotted by satellite navigation systems presents an even greater opportunity to slash shipping emissions in the next decade. By deviating from standard courses to leverage favorable winds, ships can use the extra power gained from sails to limit fuel consumption and reduce emissions. The software recommends routes that guarantee the same arrival time, ensuring ships stay on schedule.
Using a computer model simulation, researchers found that a cargo vessel equipped with sails could cut annual carbon emissions by around 10%. When optimal routing is factored in, emission cuts increase to 17%. Routes with ideal wind conditions, such as transatlantic and transpacific crossings, offer even greater potential for annual emission reductions of over 30%.
For instance, ships traveling from the UK to the US can avoid strong headwinds by using sails and optimized routing software, reducing the need for more fuel. On the return journey, ships can take advantage of tailwinds and side winds to increase propulsion.
To achieve the International Maritime Organization’s target of cutting greenhouse gas emissions by 20%-30% by 2030 and meet the Paris Agreement’s 1.5°C target, the shipping industry should embrace wind propulsion and optimized routing on promising routes. This approach allows for substantial carbon reductions in the next decade while waiting for the development of zero-carbon fuels. By integrating technology with tradition, the shipping industry can steer towards its climate goals.