The Canopée: A Sail-Driven Cargo Ship
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The shipping industry is responsible for approximately 3% of global carbon dioxide emissions, and these emissions are on the rise . However, by integrating high-tech sailing equipment into cargo ships and optimizing wind-friendly routes, we could reduce the number of cargo vessels needed by over 50%.
Shipping companies are increasingly exploring wind power as a viable solution to cut fuel costs. Various strategies are being implemented, with some companies constructing entirely new vessels equipped with traditional sails, while others are retrofitting existing ships with modern self-sailing technologies.
Innovative technologies being adopted include: hard sails that mimic the design of airplane wings, Flettner rotors made from rotating cylinders, and suction sails that enhance lift by drawing in air, alongside a giant kite similar to those used in kitesurfing.
According to Gavin Allwright from the International Windship Association, “There are many types of wind propulsion vessels, ranging from those utilizing minimal wind power to ships that derive over half of their energy solely from wind.”
Despite some wind-assisted ships still adhering to conventional operating methods—maintaining fixed speeds and direct routes—Torben Schwedt and colleagues at the German Aerospace Center are innovating by analyzing how altering the route and speed can enhance wind utilization without extending travel times. While it may seem feasible to sail purely on wind energy, he notes that most cargo must meet specific delivery schedules, with fewer trips potentially translating to reduced revenue for ship operators.
The research team envisions a future where ships can generate and store hydrogen. This emerging technology, currently implemented in a limited number of vessels, entails using excess energy from strong winds to produce hydrogen via onboard turbines. This hydrogen could then fuel the ship’s engine during times of low wind.
Utilizing restored historical weather data, the research modeled a yearlong Atlantic crossing via an optimal route, discovering that ships following these ideal paths consumed an average of 75% less energy compared to those on direct courses. Schwedt shared these findings at the recent European Geosciences Union conference in Vienna.
“The most significant savings occur when routes are completely optimized, allowing for substantial detours that may initially seem impractical,” Schwedt explains. “With this approach, we have achieved energy savings ranging from 50% to 100%.” The team aspires to demonstrate that this route optimization can also apply to predictive modeling.
Guillaume Le Grand from TOWT, a French organization specializing in sailing cargo vessels, believes in the validity of these expectations: “That’s precisely what TOWT’s sailing cargo ships have accomplished.”
Tristan Smith from University College London notes, “The notion of optimizing routes for enhancing the performance of wind-powered ships is not new and is indeed sensible.” He adds that yacht racers often select seemingly convoluted routes for this reason.
“Achieving 75-100% energy savings is theoretically feasible, but it greatly depends on the target average voyage speed, which is ultimately dictated by the economics of the vessel’s operation and its cargo,” Smith states. “In our experience, actual savings for most ocean-going vessels tend to be significantly lower.”
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Source: www.newscientist.com
