- In the vast expanse of the world’s oceans, a transformation is underway.
- The international shipping sector, made up of thousands of massive cargo ships laden with many of the goods we buy, emits carbon dioxide (CO₂) roughly equivalent to the entire country of Germany.
- Reducing shipping emissions by 34% by 2030 is necessary to stay on course with the Paris Agreement’s 1.5°C goal.
Enter a new solution with ancient origins: sails. Not the billowing canvases of centuries past but high-tech systems capable of harnessing renewable wind energy to supplement the propulsion from a ship’s engine.
Old Idea, New Technology
A number of advanced sail designs are gaining the attention of shipping firms. Two contenders include Flettner rotors, cylinders that spin to generate propulsion, and “wing sails”, which resemble airplane wings and are derived from designs used in yacht racing. Wind propulsion allows ships to use less fuel and so emit less greenhouse gas. However, in our new paper, we found that the real opportunity to slash emissions from shipping this decade lies in combining sails with optimal routes plotted by satellite navigation systems.
Optimized routing is a familiar concept to most of us. You’ll have used it by typing a destination into Google Maps and allowing its algorithms to calculate the quickest way for you to arrive at your destination. The process is similar for ships. But instead of finding the quickest journey, the software models the ship’s performance in water to calculate routes and speeds that minimize fuel use. With optimized routing and sails, ships can deviate from their standard course to seek out favorable winds. The ship may travel a longer distance but the extra power gained by the sails limits the ship’s fuel consumption and reduces the total emissions over the full journey. The software only suggests routes that guarantee the same arrival time, keeping the ship to its original schedule.
Routes with ideal wind conditions have even greater potential. The most promising are typically those far from the equator, such as transatlantic and transpacific crossings, where strong winds can fill large sails. By taking advantage of wind patterns moving across the ocean on these routes, sails and optimized routing can cut annual emissions by over 30%. Take the journey between the UK and the US as an example. A ship setting out on this voyage will typically experience strong headwinds which generate drag and push the ship backwards, meaning more fuel must be burned to maintain the same forward momentum. But by using sails and optimized routing software on this crossing, ships can avoid these headwinds and steer into more favorable winds.
Achieving The Target
The International Maritime Organization (the UN agency responsible for environmental regulation in shipping) has a target of cutting greenhouse gas emissions by 20%-30% by 2030. The Paris Agreement’s 1.5°C target requires even deeper cuts.
Our research shows that cuts to CO₂ of this magnitude are possible this decade using wind propulsion and optimized routing on promising routes. Achieving this will oblige the shipping industry to deploy existing technologies and practices and shift its focus from fuel alone, as zero-carbon fuels will take longer to develop.
As we sail further into the 21st century, our research delivers a clear message to the shipping industry: substantial carbon reductions are feasible this decade. Here is an old idea, one that integrates technology with tradition, that can steer international shipping towards its climate goals.
Did you subscribe to our daily newsletter?
It’s Free! Click here to Subscribe
Source: Manchesterac
