Inflatable sails to give cargo ships a greener push

Dirty cargo ships urgently searching for cleaner propulsion alternatives might consider a new spin on an old idea: inflatable sails.

What's new: The Wing Sail Mobility (WISAMO) project, an automated, inflatable wing sail system, was introduced this week by Michelin, the French company known for its tires and restaurant guides.

• Two Swiss inventors co-developed the system with Michelin R&D.
• The telescopic mast is retractable, making it easy for a ship to enter harbors and pass under bridges.
• The puffy, 1,000-square-foot sails, each shaped like an airplane wing, automatically fold up like an accordion on the ship's deck when not in use.

Why it matters: Michelin says the system — which operates in addition to conventional propulsion — can improve a ship’s fuel efficiency by up to 20%. (Watch a video of how it might work here.)

The big picture: The shipping industry, which accounts for almost 3% of the world's carbon emissions, is scrambling to adopt cleaner technologies.

• In 2018 the International Maritime Organization, a United Nations regulatory agency, set tough new targets for greenhouse gas reduction.
• By 2050, shipping needs to reduce emissions by 50% compared to 2008 levels, with the goal of eventually phasing out all greenhouse emissions.

What to watch: French sailor and racer Michel Desjoyeaux has been testing the WISAMO system on a sailboat.

• It will then be tested on a merchant ship in 2022 before going into production.
• The plug-and-play design can be retrofitted to existing vessels — including pleasure craft — or designed into new ships.