“We're developing models to help decarbonize the maritime industry”

Æther Swiss Kite is a cross-disciplinary project initiated three years ago in the wake of the SP80 venture – another EPFL MAKE project that eventually resulted in a startup. While the goal of SP80 was to beat the world speed sailing record with a kite and streamlined boat, Æther has an entirely different focus. The 60-odd students working on the project aim to cut shipping vessels’ greenhouse gas emissions by 20% – or perhaps even more depending on the route, wind conditions and boat speed. Specifically, they are developing an automated control system that can autonomously launch and fly a large kite attached to a shipping vessel.

“Some companies are already marketing this kind of technology, such as the SeaKite system from Beyond the Sea,” says Emmie Martin-Cocher, a second-year master’s student in mechanical engineering and the former vice president of the Æther Swiss Kite student association. “These systems are designed to be deployed on a large scale. Their kite wings measure some 100 square meters and fly 100 to 300 meters above the boat.”

The project team has no intention of revolutionizing the field or competing against these companies. “We’re not an industry heavyweight when it comes to cutting the maritime industry’s carbon emissions,” says Vincent Lellu, a robotics student in the final year of his master’s degree and the association’s new vice president. “But what we can do is help those companies by contributing our open-source control system for improving kite traction.”

Kites moving in figure eights

To pull a boat effectively, the kites need to fly in what’s known as the “power zone” where they can achieve maximum traction. But that’s also where they are the hardest to control. Therefore the kites must follow a figure-eight pattern, just like in kitesurfing, and move in and out of this area to strike the right balance between traction and stability.

Developing any new technology comes with its share of glitches, and this project was no exception. Martin-Cocher admits that their kite has crashed a few times – and will probably crash a few more when the team begins testing fully automated control. Some of the kite wings even tore apart beneath the boat.

Guided with a PS4 controller

As a first step, the project team had to build the structure for developing and testing the kite controls. “You can’t start programming the control algorithms until you have a kite, a boat to pull and the entire load-bearing structure,” says Martin-Cocher. “There are also the motors, the batteries to power them, the wind sensors and more.”

The team has spent several years designing the system architecture – and it’s still a work in progress. For instance, when more powerful motors became available, the team had to update the system’s electronics and mechanical fastenings so that the motors could be installed. Now that the main structure has been built, the focus is on enhancing the algorithms so that the system is fully autonomous. The team initially flew the kite by hand, and then remotely with the help of a PS4 controller. A motor winds and unwinds the ropes to direct the kite’s movements.

Technology adaptable to existing boats

Pierre-Louis Peter, a second-year master’s student in energy, joined the association when it was created and became its president last year. For his semester project, he aimed to quantify the amount of boat fuel that the Æther Swiss Kite system could save. The system is designed to be easily adapted to existing boat fleets. “We want boat operators to be able to install the control box on the deck of a vessel and then use the kite to pull the vessel without having to make any major adjustments,” says Peter. That would reduce the fuel requirement with no need to change the vessel’s architecture or undertake costly renovation work. “Unfortunately, the maritime industry is still heavily reliant on fossil fuels,” he says.

Like any wind-driven technology, the Æther Swiss Kite system is dependent on how the wind blows. For instance, if a boat is traveling at a speed of 10 knots in the same direction as the wind, and the wind is blowing at 12 knots, then the kite has only a 2-knot differential to exploit for traction. “One option could be to lower the boat’s speed and increase the amount of traction, which would cut fuel use,” says Martin-Cocher. “But that kind of decision needs to be made by shipping companies, and many of them would prefer to keep vessels moving quickly in order to maintain operational efficiency.”

Zoé Corlouer, who just completed the second year of her bachelor’s degree in mechanical engineering, recently joined the association to manage its communications and social media. She believes that performance should be viewed as part of a bigger picture. “Technological innovation isn’t the only answer. We also need to change our behaviors and our consumer habits more broadly.”

In their first collaboration with industry, the team will carry out a pilot test on Lake Neuchâtel in October using a barge provided by a gravel quarry. The testing will last one week. “It’ll be the first time we try out our system at scale,” says Peter. The barge is 18 meters long and weighs 10 metric tons, providing a formidable first challenge for the students.Le lecteur anglo ne comprendrait pas forcément le lien entre le projet et une association.